A Suggest possible environmental conditions under which the experiment was carried out between 30 and 60 minutes 2mks b Account for the results obtained for plant C 2mks c Suggest the habitat for plant A and B. Give reasons for your answer. 4mks Biology paper 1, 2 3 www.freekcsepastpapers.com Habitat for plant A Reason Habitat for plant B Reasons c The relative rates of photosynthesis in a certain plant were determined at different temperature. The results are shown below. Temperature o C Relative rate of photosynthesis mg hr 25 26 30 37 35 45 40 25 a Account for the rate of photosynthesis at; i 35 o C 2 mks ii 40 o C 2mks b Explain what happens during dark reaction in photosynthesis. 2 mks c In an experiment to show that Oxygen gas is a by-product of photosynthesis a water plant is used. Give two reasons why a terrestrial plant is not used. 2mks d The figure below shows a diagram of part of the male reproductive system. A State the letter on Fig. 5.1 that identifies: 3 mks i Where sperm are made. Ii The part that carries urine and sperm out of the body. Iii Where the fluid that is added to the sperm is made. B Sperm must pass through different structures in the female reproductive system to reach an egg cell. State the names of three of these structures. 3marks c State two ways that sperm are adapted for their function. 2mks e a Distinguish between the terms homodont and heterodont. 1mk b What is the function of carnasial teeth? 1mk c A certain animal has no incisors, no canines, 6 premolars and 6 molars in its upper jaw, in the lower jaw there are 6 incisors, 2 canines, 6 premolars and 6 molars. Write its dental formula 1mk d Suggest the likely type of food eaten by the organism 1mk e The action of ptyalin stops at the stomach. Explain. 1mk f State a factor that denatures enzymes.


Name three methods of population estimation. 3mks ii a Explain the role of human skin in protection of the body. 10mks b Explain the importance of protecting the forest ecosystem with reference to the following. 10mks i Pollution. 4mks ii Water conservation. 4mks iii Climate change. 2mks 8. How are xerophytes adapted to their habitats? 20mks MURANG A SOUTH 231 3 BIOLOGY PAPER 3 Instructions: Answer all question in the spaces provided. F a i You are provided with a pestle, mortar, scalpel, specimen Q and R. Cut from each a cube, each measuring 1cm by 1cm. Put them each in a different test tube having 10mls of solution X. Record the observations in the table below? 2 Mks Specimen ObservationBiology paper 1, 2 3 www.freekcsepastpapers.com Specimen Q Specimen R ii Account for the observations in the experiment involving specimen Q and R? 2 mks ii i Using the remaining portion of specimen Q, Cut 2 other pieces measuring 1cm by 1cm, Crush them separately to form a paste and put them in boiling tubes labelled A and B. To the paste in boiling tube labelled A, add 5mls of solution X. Record the observation in the table below. 1mk BOILING TUBE OBSERVATION A To the paste in boiling tube labeled B add 10mls of distilled water and boil for 5 minutes then allow it cool then add 5mls of solution X. Record the observation in the table below. 1 mk BOILING TUBE OBSERVATION B ii Account for the observations made in b i above involving boiling tube A and B 4 marks Boiling tube A Boiling tube B iii Name the biological substance being investigated and its significance to the living tissues 2mks Biological substance Significance iv Name the factor being investigated in question 2 b above 1mk g a Identify specimens labeled M and G provided. 1mk b From specimen labeled G name any two organs 2mks c i From specimen M remove one leaf.


Record the observation in the table below. 1 mk BOILING TUBE OBSERVATION B ii Account for the observations made in b i above involving boiling tube A and B 4 marks Boiling tube A Boiling tube B iii Name the biological substance being investigated and its significance to the living tissues 2mks Biological substance Significance iv Name the factor being investigated in question 2 b above 1mk g a Identify specimens labeled M and G provided. 1mk b From specimen labeled G name any two organs 2mks c i From specimen M remove one leaf. List any two observable features 2mks ii Use the leaf in part C i above; place that leaf on graph paper provided and trace it carefully on the graph paper. From the traced outline, 1. Count the number of complete full square .. 1mk 2. Count the number of incomplete squares 1mk 3. Calculate the area of each square in cm2 ................... 1mk 4. Calculate the area of the leaf outline...................... 2mks 5. From the information obtained in part d above compare it with a leaf in specimen G. What advantage does a leaf from specimen G has over leaf from specimen M? 1mk Biology paper 1, 2 3 www.freekcsepastpapers.com 6. Giving a reason, in which class does a plant from which specimen G was obtained. 2mks Class Reason h A Study the photographs below of specimen. A, B, and D and then answer the questions that follows. A Name the condition exhibited in A which hinders self- fertilization. 1mk b Explain how the above condition hinders self-fertilization. 1mk c i State the division where plant in photograph D belong and give reason for your answer. Division 1mk Reason 1mk ii State the type of nutrition exhibited by specimen D. 1mk iii Give a reason for your answer in d ii above. 1mk iv Give the function of the structure labelled Y. 1mk 3 B Photograph 1 below represent a plant that grow in relatively wet habitats.


1mk iii Give a reason for your answer in d ii above. 1mk iv Give the function of the structure labelled Y. 1mk 3 B Photograph 1 below represent a plant that grow in relatively wet habitats. Photograph 2 is a magnified portion of the underside of the leaf of photograph 1. Biology paper 1, 2 3 www.freekcsepastpapers.com a State the common name of the plant and state the plant division it belongs. 2mks Common name: Division: b Name the structure labelled T and state its function. 2mks c Name the structure labeled A and B. 2mks d State one major difference between structure labelled B and the rhizoids of a moss plant. 1mk Biology paper 1, 2 3 www.freekcsepastpapers.com MURANG A SOUTH BIOLOGY F4 P3 All candidates to be supplied with: 1. Pestle and mortar 2. Specimen Q: LIVER. 1cm by 1cm per student 3. Specimen R: Banana raw: 3 students can share 1 4. Measuring cylinder 5. Ruler 6. 20ml Hydrogen peroxide Solution X 7. Source of heat 8. 2 Boiling tubes 9. 4 test tubes 10. Distilled water 11. Labels 12. Stop watch. 13. A mango twig with about three leaves labeled m. leaves should be less than 15cm long 14. Any grass twig with about three leaves labeled G. 15. A magnifying hand lens. Biology paper 1, 2 3 www.freekcsepastpapers.comBiology paper 1, 2 3 www.freekcsepastpapers.com WEITHAGA 231 1 BIOLOGY PAPER 1 JULY AUGUST 2023 1. A State the branch of Biology that would be used in solving the problem of disputed parentage. 1mk b Study the diagram below and answer questions that follow i What is the name given to the apparatus shown above 1mk ii What is its use in Biological studies? 1mks 2.


A State the branch of Biology that would be used in solving the problem of disputed parentage. 1mk b Study the diagram below and answer questions that follow i What is the name given to the apparatus shown above 1mk ii What is its use in Biological studies? 1mks 2. The diagram below shows onion cells in a field of view of a light microscope X400 Using the dark line as diameter of field of view, determine the actual diameter of one cell 3mks 3. Identify the functions of a light microscope as shown by the following diagrams 2mks a Function: . B Function 4. Name the main product of the dark stage of photosynthesis. L mark 5. State the function of muscles found in the alimentary canal of mammals. 1mks 6. A What is the function of Sodium hydrogen Carbonate that is added to test solution of non reducing sugars. 1 mark b The equation below represents a process X which is controlled by enzymes. I Name the process X and enzyme R. 2 marks Process X Biology paper 1, 2 3 www.freekcsepastpapers.com Enzyme R 7. Give two forms in which carbon IV oxide is transported in human blood. 2 marks 8. It was found that during germination of pea seeds 9.3cm3 of carbon IV oxide was produced while 9.1cm3 of oxygen was used up. A Calculate the respiratory quotient RQ of the reaction taking place. 2 marks b Identify the type of food substance being metabolized. 1 mark 9. A new respiratory virus COVID 19 was discovered in December 2019 in china. A Name the main organ affected by the virus lmark b State any two symptoms that suggest one may have the virus 2 marks c State preventive measures being employed to curb spread of COVID 19. 1 marks 10. Nitrogen in the atmosphere cannot be directly utilized by plants. State three natural ways it is made available for plant use. 3 marks 11.


Nitrogen in the atmosphere cannot be directly utilized by plants. State three natural ways it is made available for plant use. 3 marks 11. The diagram below represents a longitudinal section of a fruit a Name structures labelled P 1 mark b Describe two adaptations of the fruit for its mode of dispersal. I Mode of dispersal 1mark ii Adaptations 2marks . 12. The diagram below shows regions of growth in a root. Study it and answer the questions that follow. A State the function of part K 1 mark b . State two characteristics of the cells found in zone C 2 marks 13. The dark variety of peppered moth is predominantly found in industrial cities while the spackled white variety is predominantly found in rural areas of Europe. I Name the phenomenon illustrated above I mark ii What is the significance of the phenomenon above to the organism. 1 mark 14. The table below shows the effect of wind, still air and stomatal opening on the rate of transpiration of a plant in milligrams of water lost per hour dm2. Study the table and answer the following questions Stomatal opening m 1 2 3 4 5 6 7 Windy 40 63 74 86 94 110 124 Still air 0 6 12 19 23 27 30 a i Compare the rates of transpiration in windy and still air conditions 1mk A B C KBiology paper 1, 2 3 www.freekcsepastpapers.com ii Explain your observation in a i above 2mks b How does stomatal opening affect transpiration rate? 1mark 15. Explain why division Pteridophyta is considered more advanced than division Bryophyta. 3mks 16. Explain why tropical forests do not have undergrowth 2marks . 17. A bone obtained from a mammal is represented by the diagram below. A Name the bone. 1mk b Which bones articulates with the bone shown in the diagram at the notch? 2mks 18. A . Two pieces of leaf petiole were cut as shown in the diagram below then each piece placed in solution of different concentration. I .


A . Two pieces of leaf petiole were cut as shown in the diagram below then each piece placed in solution of different concentration. I . What physiological process was being investigated in this experiment? 1mark . Ii . Suggest the type of solution piece B was placed. 1mark . Iii . Explain the appearance of piece A after 15minutes. 2marks . B Explain the effect of water logging on the rate of mineral absorption. 2marks . 19. Study the diagram below and answer the questions that follow; a State the expected result at the end of the experiment 1mk b . Account for your answer in a above 2mks 20. Give two reasons why transportation of carbon IV oxide in a red blood cell is advantageous. 2mks 21. State the change that occurs in arterioles in the human skin during thermoregulation 2mks 22 a Name the fluid that is produced by sebaceous gland 1mk b . State two roles of this fluid 2mks Biology paper 1, 2 3 www.freekcsepastpapers.com 23. The diagram below illustrates the structure of bread moulds ; a Name the part labeled J 1mk b . State the functions of the structure labeled K 2mks 24. What is meant by the term biological control? 1mk 25. The diagram below represents a stage during cell division a i Identify the stage of the cell division 1mark ii . Give three reasons for your answer in a i above 3marks b . Name the structures labeled M 1marks 26. Distinguish between divergent and convergent evolution 2mks 27. State three survival values of tactic response. 3marks . 28. The diagram shows a section through part of the mammalian kidney. A Name the parts labeled 1 and 2. 2mks b State two ways in which nephrons of desert animals differ from those of man. 2mks Biology paper 1, 2 3 www.freekcsepastpapers.com WEITHAGA 231 2 BIOLOGY PAPER 2 Theory July August 2023 SECTION A 40 marks 1. A Define sex linkage.


2mks b State two ways in which nephrons of desert animals differ from those of man. 2mks Biology paper 1, 2 3 www.freekcsepastpapers.com WEITHAGA 231 2 BIOLOGY PAPER 2 Theory July August 2023 SECTION A 40 marks 1. A Define sex linkage. 1mk b In a marriage of Jane and Otieno who are both normal for hemophiliac condition, gave birth to four children Susan, Grace, Tom and Peter. Tom the second born child was hemophilic. Later in life Tom married Alice who was normal. Their first born child was hemophiliac. Let H represent gene for normal condition. I What was the genotype of Alice. 1mk ii Work out the phenotypic ratio of F2. 4mks c How does the police force use knowledge on genetics. 1mk d What is the name given to points of contact in a pair of homologous chromosomes 1mk 2. The table below shows the approximate distribution of blood groups in a sample of 100 people in a population. Blood group Frequency Rhesus ve Rhesus -ve A 26 22 4 B 20 18 2 AB 4 3 1 O 50 43 8 a Calculate the percentage of Rhesus negative Rh-ve individuals in the population? 1 mk b Account for i The large number of blood group O individuals in a population. 2 mks ii The small number of individuals with blood group AB. 2 mks c The diagram below represents a blood smear on a glass slide. I State the importance of structure C being large numbers in the blood smear. 1mk ii Give a reason why structure C would be found in large numbers in high altitude than in low altitude. 1mk iii Name the process by which structure A would engulf structure B. 1mk A B CBiology paper 1, 2 3 www.freekcsepastpapers.com 3. The graph below represents the population of animals in a pond over a period of 9 months. The pond is situated in a country with evenly distributed rainfall throughout the year.


1mk A B CBiology paper 1, 2 3 www.freekcsepastpapers.com 3. The graph below represents the population of animals in a pond over a period of 9 months. The pond is situated in a country with evenly distributed rainfall throughout the year. A What times of the year affect the number of the animals adversely 2mks b What is the average number of animals in the pond between April and may 2mks c Give three possible reasons for the drop in the number of animals in the pond 3mks d Give a reason to explain the events in the pond between March and April 1mks 4. A Distinguish between the terms homodont and heterodont 1mk b What is the function of carnassial teeth? 1mk c The diagram below represents the lower jaw of a mammal i Name the mode of nutrition of the mammal whose jaw is shown above 1mk ii State one structural and one functional differences between the teeth labeled J and L 2mks iii a Name the toothless gap labeled K 1mk b State the function of the gap 1mk c Name the substance that is responsible for hardening of teeth 1mk Biology paper 1, 2 3 www.freekcsepastpapers.comBiology paper 1, 2 3 www.freekcsepastpapers.com 5. The diagram below illustrates an experiment to determine the rate of respiration in a small insect. A Name the chemical compound labeled X and state its function. 2 marks Name Function b Why is it necessary to place the flask in a water bath? 1 mark c What changes would you expect to observe in the level of coloured water in the capillary tube after the experiment has run for five minutes? 1 mark d Explain the results stated in part c above. 3 marks e Suggest a control experiment that would be set up for the above experiment. 1 mark SECTION B 40 marks Answer question 6 compulsory and either question 7 or 8 in the spaces provided after question 8 6.


1 mark d Explain the results stated in part c above. 3 marks e Suggest a control experiment that would be set up for the above experiment. 1 mark SECTION B 40 marks Answer question 6 compulsory and either question 7 or 8 in the spaces provided after question 8 6. A research was carried out to determine the trend of growth for some boys and girls. Their average mass in kilograms was taken separately for a period of 20 years and tabulated as shown in the table below. Age Average Mass of boys kg Average mass of girls kg 0 2.5 2.5 2 11.1 11.5 4 15.0 16.0 6 18.5 19.3 8 22.1 27.1 10 25.1 27.1 12 27.5 30.5 14 37.0 35.5 16 44.0 44.0 18 46.9 52.5 20 48.5 55.0 a On the same axis draw a graph of average mass of girls and of boys against the age. 7 marks b From the graph, determine the; i Mass for boys at age of 11 years. 1mark Biology paper 1, 2 3 www.freekcsepastpapers.com ii Growth rate in girls between ages 13 and 15 3 marks c Account for the change in the mass of girls during the age stated in ii above. 2 marks d Explain the trend observed in the curves for both boys and girls. 2 marks e Why do girls above 10 years require intake of food that is richer in iron than boys of the same age. 1 mark f Mention two other factors apart from the diet that affect the rate of growth in boys and girls. 2 marks g Apart from using average mass to estimate growth in human beings, name two other parameters that can be used. 2 marks 7. A Describe the adaptation of floating water lily leaf to its photosynthetic function. 10mks b Describe the activities that take place in the chloroplast of growing plants.


2 marks 7. A Describe the adaptation of floating water lily leaf to its photosynthetic function. 10mks b Describe the activities that take place in the chloroplast of growing plants. 10mks 8. A Explain how the various components of blood cells are adapted to perform their functions. 12mks b Discuss the process of double fertilization in flowering plants. 8mks WEITHAGA 231 3 BIOLOGY PAPER 3 PRACTICAL 1. You are provided with five potato cylinders each measuring 5cm long, liquid S1 and S2, Hydrogen Peroxide, dilute Hydrochloric Acid, and test tubes labeled A,B and C. a i Place one cylinder in a beaker containing liquid labeled S1 and another in the liquid labeled S2. Allow to stand for 30 minutes, then remove the cylinders, wipe them dry using blotting paper. Measure each cylinder in centimeters and record their length and texture in the table given below. 4 marks CYLINDER LENGTH IN CM TEXTURE LIQUID S1 LIQUID S2 ii Account for the results obtained in a i above 2marks iii . Using a scalpel cut one of the cylinders into 5 parts each one centimeter long. Put the pieces into test tube A. Crush the other two using mortar and pestle into a paste. Divide the paste into two equal lots. Put one lot into test tube B and the other into test tube C. To each of the test tubes A and B add 2cm3 of hydrogen peroxide and to test tube C add 1 cm3 of dilute Hydrochloric Acid, then 2cm3 of hydrogen peroxide. Record your observation below. 3marks Test tube A Test tube B Test tube C iv Write a word equation for the reaction that occurs in the test tubes 1mark v Account for the rate of reaction in test tube A, B and C. 4 marks Biology paper 1, 2 3 www.freekcsepastpapers.com 2.


Record your observation below. 3marks Test tube A Test tube B Test tube C iv Write a word equation for the reaction that occurs in the test tubes 1mark v Account for the rate of reaction in test tube A, B and C. 4 marks Biology paper 1, 2 3 www.freekcsepastpapers.com 2. You are provided with plant specimens labeled A, B, C, D, E and F a Using features inorder given below, construct a dichotomous key that can be used to identify the specimens provided 10marks Simple or compound leaves Leaf venation Leaf margin Arrangement of leaves on the stem Pinnate bipinnate or trifoliate nature of leaves b Give two observable differences between stem of specimen labeled E and D 2mks 3. Examine the photographs I and II of seedling specimen shown below and answer the questions that follows; a i Name the parts labelled C and D. 2mks ii Name two hormones that brings about cell division in parts labelled A 2mks b i Name the class to which the specimen belongs. Lmk ii Give two reasons, using observable features to support your answer in b i above 2mks c Give two functions of the structure labeled D. 2mks d Explain how the curvature labeled C is formed 3mks e . Name the type of germination exhibited by the seedlings. Give a reason for your answer. 2mks Type ReasonBiology paper 1, 2 3 www.freekcsepastpapers.com WEITHAGA 231 3 BIOLOGY PAPER 3 PRACTICAL CONFIDENTIAL REQUIREMENTS Each candidate will require the following. 5 Potato cylinders measuring 5cm long and a half cm 0.5 cm wide. Concentrated salt solution in a beaker labeled S2 Distilled water in a beaker labeled S1 10 ml of hydrogen peroxide in a beaker Dilute hydrochloric acid in a beaker 3 test tubes labeled A,B and C. A pair of forceps. A ruler graduated in centimeters cm A test tube rack Filter paper.


Concentrated salt solution in a beaker labeled S2 Distilled water in a beaker labeled S1 10 ml of hydrogen peroxide in a beaker Dilute hydrochloric acid in a beaker 3 test tubes labeled A,B and C. A pair of forceps. A ruler graduated in centimeters cm A test tube rack Filter paper. 2 blackjack twig with at least two leaves labeled specimen A Accacia wattle tree twig with at least two leaves labeled specimen B Tradescentia Leaf labeled specimen C Lantana Tick berry twig with at least two leaves labeled specimen D Bougainvillea twig with at least two leaves labeled specimen E Jacaranda twig with at least two leaves labeled specimen FBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com CEKENAS END OF TERM TWO EXAM 2023 231 1 BIOLOGY PAPER 1 THEORY 1. State the name given to the study of: 2marks i Chemical changes in living organisms. Ii Insects. 2. State the category of variation into which the following traits fall. 2marks a i Skin pigmentation. Ii Blood group . B Give two possible genotypes of blood group A. 2marks 3. Give two differences between scientific names and common names. 2marks Scientific Names Common Names 4. Explain two adaptation that enable the halophytes to survive in their habitats. 2marks 5. I What is parthenogenesis. 1mark ii Monocotyledonous plants do not undergo secondary growth. Explain, 1mark 6. Name two classes of Phylum Arthropoda whose members head is fused with the thorax. 2marks 7. Name two excretory products produced by both plants and animals. 2marks 8. The shirt of a student was stained by a solution of DCPIP. A friend advised him to wash with lemon juice. Explain. 1mark 9. Two freshly cut banana peels A and B measuring 4cm long were cut, which were later placed in solutions of different concentrations in two separate beakers for 30minutes. The appearance after 30minutes is as shown below.


1mark 9. Two freshly cut banana peels A and B measuring 4cm long were cut, which were later placed in solutions of different concentrations in two separate beakers for 30minutes. The appearance after 30minutes is as shown below. A What is the nature of the solution in which piece B was placed. 1mark b Account for the appearance of piece A. 3marks 10. I The ovum is fertilized only by one sperm yet there is millions of sperm surrounding the ovum. Explain. 1mark II Give the role of the following parts of the male reproductive system. A Epididymis 1mark b Prostate gland 1mark 11. When a person has oxygen debt the heart beat increases. Give two importance of the increase in heart beat. 2marks . BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com 12. The diagram below shows part of a nephron from the human kidney. A Give two factors that lead to creation of higher pressure in the structure labelled Q. 2marks b On the diagram above label the part where the sodium ions are reabsorbed and write down the hormone involve in regulating the level of this ions 2marks Name of the hormone; 13. Explain how the following parts of a light microscope are modified to perform their function i Diaphragm 1mark ii Mirror. 1mark 14. A Explain two adaptations of cell membrane to its function. 2marks b Why is oxyhaemoglobin formation is highly preferred during transportation of oxygen in the body. 2marks 15. I Explain how smoking of tobacco lead to lung cancer. 1mark II. How does age affect the breathing rate in human? 2marks 16. In an experiment to investigate an aspect of digestion, two test tubes A and B were set as shown below. The set up was left for 30 minutes and the temperature of water was maintained at 370C. The resulting content in each test tube A and B were placed into two separate visking tubing which were then placed in a beaker containing iodine solution, for 20 minutes. A What was the observation that was made in the visking tubing containing contents of test tube A.


The set up was left for 30 minutes and the temperature of water was maintained at 370C. The resulting content in each test tube A and B were placed into two separate visking tubing which were then placed in a beaker containing iodine solution, for 20 minutes. A What was the observation that was made in the visking tubing containing contents of test tube A. 1mark b Account for the result in visking tubing which was containing contents of test tube B. 3marks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com 17. During a biological excursion a group of form 4 students collected plant specimen whose reproductive organ is shown below. I Name the sub-division of the plant in which the above specimen was obtained. 1mark ii Other than the presence of the above characteristics, state two characteristics of plants in the subdivision named above. 2marks 18. Enzymes are important in various physiological processes in living things. A Differentiate between an enzyme and a hormone 1mark b Name one property of an enzyme exhibited by the lock and key hypothesis 1mark 19. I The transverse section of a young dicotyledous root was cut and iodine solution was applied. One of the part of the section turned to blue-black colour. Identify the part of the root and give a reason for your answer. Part 1mark Reason 1mark II. Distinguish between transpiration and guttation. 1mark 20. The diagram below shows a cell undergoing a stage in cell division. With a reason, identify this stage 2mark Identify Reason . 21. A Define the term immunity. 1mark b Identify one immunizable disease in Kenya 1mark c State two ways in which lymphocytes kill disease causing microorganism. 2marks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com 22. Study the diagram below and answer the questions that follow. I With an arrow, indicate on the diagram the direction of the impulse through the neuron. 1mark ii State the function of the parts labelled P 1mark 23. Name the type of response exhibited by; i Sperm cell when it swims towards the ovum.


I With an arrow, indicate on the diagram the direction of the impulse through the neuron. 1mark ii State the function of the parts labelled P 1mark 23. Name the type of response exhibited by; i Sperm cell when it swims towards the ovum. 1mark ii Leaves of Mimosa pudica when they fold their leaves after being touched. 1mark 24. A Distinguish between hypogeal and epigeal germination. 1mark b State two internal factors necessary for germination 2marks 25. A Give two importance of divergent evolution to animals 2marks b Explain two limitations of fossil record as an evidence for evolution 2marks 26. What causes the following diseases? A Diabetes mellitus 1mark b Diabetes inspidus 1mark 27. Study the diagram below and answer the questions that follows. A Identify the tooth. 1mark b Give a reason for your answer in 27 a above 1mark c State two mineral ions deposited on the bones to harden them. 2marks 28. I. The following is food chain that was presented by a student in class. Grasshopper Lizard Chicken Hawk State two errors that are made in the food chain 2marks II. Give a reason why pyramid of biomass is considered to be more accurate over the pyramid of numbers. 1mark 29. Below are cross section of diagrams of fruits. Identify the type of placentation present in the three diagrams 3marks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com CEKENAS END OF TERM TWO EXAM 2023 231 2 BIOLOGY PAPER 2 THEORY JULY AUGUST 2023 SECTION A: 40 MARKS 1. The figure below shows the teeth in the lower jaw of an adult human a i Name the teeth labelled X and Z 2marks ii Describe the functions of teeth Y and Z 2marks b Name one mineral and one vitamin that are essential for the healthy development of teeth 1mark c The figure below shows a section through a tooth. I Tooth decay is caused by bacteria getting into the dentine.


Identify the type of placentation present in the three diagrams 3marks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com CEKENAS END OF TERM TWO EXAM 2023 231 2 BIOLOGY PAPER 2 THEORY JULY AUGUST 2023 SECTION A: 40 MARKS 1. The figure below shows the teeth in the lower jaw of an adult human a i Name the teeth labelled X and Z 2marks ii Describe the functions of teeth Y and Z 2marks b Name one mineral and one vitamin that are essential for the healthy development of teeth 1mark c The figure below shows a section through a tooth. I Tooth decay is caused by bacteria getting into the dentine. Explain how bacteria can enter the dentine 2marks ii List one action you could take to reduce the risk of tooth decay 1mark 2. A What are the analogous structure as used in evolution 1mark b How do disease causing micro-organisms become resistant to drugs 3mark c The diagram below represents a bone of a mammalBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com i Identify the bone 1mark ii Name the bone that articulate at the point labelled F 1mark iii Explain two adaptations of the bone identified in i above 2marks 3. Study the flow chart below of a process that takes place in both plants and animals a Name the above process 1mark b i In the above process name the chemical reaction represented by X 1mark ii Name the part of the cell where the enzyme controlled reactions in b i above takes place 1mark c Name the product Z in i Plants 1mark ii Animals 1mark d What would be the fate of pyruvic Acid if oxygen supply is availed in the mitochondria of an animal cell 2marks e What is meant by the term oxygen debt 1mark 4.


Explain how bacteria can enter the dentine 2marks ii List one action you could take to reduce the risk of tooth decay 1mark 2. A What are the analogous structure as used in evolution 1mark b How do disease causing micro-organisms become resistant to drugs 3mark c The diagram below represents a bone of a mammalBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com i Identify the bone 1mark ii Name the bone that articulate at the point labelled F 1mark iii Explain two adaptations of the bone identified in i above 2marks 3. Study the flow chart below of a process that takes place in both plants and animals a Name the above process 1mark b i In the above process name the chemical reaction represented by X 1mark ii Name the part of the cell where the enzyme controlled reactions in b i above takes place 1mark c Name the product Z in i Plants 1mark ii Animals 1mark d What would be the fate of pyruvic Acid if oxygen supply is availed in the mitochondria of an animal cell 2marks e What is meant by the term oxygen debt 1mark 4. A Differentiate between the following terms i Dominant gene and recessive gene 1mark ii Continuous variation and discontinuous variation 1mark b In Drosophila melanogaster the gene for eye colour is sex linked. The gene for red eye is dominant. A cross was made between homozygous red eyed female and a white eyed male. Work out the phenotypic ration of the F1 generation. Use R to represent the gene for red eyes 4marks c Suggest two reasons to explain why Drosophila melanogaster is most preferred for studies in modern genetics. 2marks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com 5.


A Tie one end of the visking tubing tightly using a thread. Put 10ml of solution K and 1 ml of solution M3 into the visking tubing. Tie the other end of the visking tubing. Place the visking tubing in a beaker half filled with iodine solution. Take a second visking tubing and repeat the same using M4. Place the beakers containing the visking tubing in a water bath maintained between 35 38 0C. Allow the setups to stand for 30minutes. Then after 30 minutes remove the visking tubings and test their contents and those of the beakers. SAMPLE 1 K M3 6 MARKS CONTENTS IN TEST OBSERVATION CONCLUSION VISKING TUBING Iodine test Benedict s test Biuret s test BEAKER Iodine test Benedict s test Biuret s test SAMPLE 2 K M4 6MARKS CONTENTS IN TEST OBSERVATION CONCLUSION VISKING TUBING Iodine test Benedict s test Biuret s test BEAKER Iodine test Benedict s test Biuret s test b Account for the results in: i Table 1 1mark ii Table 2 2marks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com 2. You have been provided with specimen labelled X. The specimen and the photograph of Y are obtained from the same animal. Use them to answer the question that follow. A Giving two reasons identify Y. i Identity 1mark ii Reasons 2marks b Give two adaptations of the specimen labelled X 2marks c State two observable differences between X and Y 2marks d Make a drawing showing the anterior view of X and label all the parts 4marks e The photograph below shows bones from another animalBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com i Which part of the body was H obtained from 1mark ii Identify G2 1mark iii With a reason name the type of joint at the proximal end of specimen H 2marks 3.


Use them to answer the question that follow. A Giving two reasons identify Y. i Identity 1mark ii Reasons 2marks b Give two adaptations of the specimen labelled X 2marks c State two observable differences between X and Y 2marks d Make a drawing showing the anterior view of X and label all the parts 4marks e The photograph below shows bones from another animalBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com i Which part of the body was H obtained from 1mark ii Identify G2 1mark iii With a reason name the type of joint at the proximal end of specimen H 2marks 3. Study the photographs below and answer the questions that follow a Name the type of relationship in: i Photograph W 1mark ii Photograph M 1mark b Explain your answer in a ii above 2marks c What is the importance of the relationship taking place in the photograph W 1mark d Using observable feature only explain two ways in which the flower is adapted for the activity taking place in photograph M 2marks e . I Give the biological term used to refer to the phenomenon captured in photograph W between organisms A and B towards C 1mark BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com ii State two implications of the phenomenon mentioned in d i above 2marks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com CEKENAS END OF TERM TWO EXAM 2023 231 3 BIOLOGY PAPER 3 PRACTICAL CONFIDENTIAL INSTRUCTIONS These instructions are to enable the head of institution and the teacher in charge of biology to make adequate preparations for 231 3 Biology Practical No one else should have access to this information either directly or indirectly.


I Identity 1mark ii Reasons 2marks b Give two adaptations of the specimen labelled X 2marks c State two observable differences between X and Y 2marks d Make a drawing showing the anterior view of X and label all the parts 4marks e The photograph below shows bones from another animalBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com i Which part of the body was H obtained from 1mark ii Identify G2 1mark iii With a reason name the type of joint at the proximal end of specimen H 2marks 3. Study the photographs below and answer the questions that follow a Name the type of relationship in: i Photograph W 1mark ii Photograph M 1mark b Explain your answer in a ii above 2marks c What is the importance of the relationship taking place in the photograph W 1mark d Using observable feature only explain two ways in which the flower is adapted for the activity taking place in photograph M 2marks e . I Give the biological term used to refer to the phenomenon captured in photograph W between organisms A and B towards C 1mark BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com ii State two implications of the phenomenon mentioned in d i above 2marks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com CEKENAS END OF TERM TWO EXAM 2023 231 3 BIOLOGY PAPER 3 PRACTICAL CONFIDENTIAL INSTRUCTIONS These instructions are to enable the head of institution and the teacher in charge of biology to make adequate preparations for 231 3 Biology Practical No one else should have access to this information either directly or indirectly. Each candidate requires the following 30 ml of solution K mixture of starch and albumin 3 ml of solution M3 enzyme diastase 3 ml of solution M4 boiled enzyme diastase Iodine solution 100ml 6 test tubes in a test tube rack Specimen X Thoracic vertebrae Test tube holder Means of timing Thermometer Water bath to hold two 100ml beakers simultaneously Two visking tubings each 6cm long and threads to tie their ends Two 100 ml beakers Access to Means of heating Sodium hydroxide solution 10 Copper II sulphate solution 1 Iodine solution Benedict s solutionBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com GATUNDU SOUTH JOINT EXAMINATIONS 2023 231 1 BIOLOGY PAPER 1 Theory 1.


Study the photographs below and answer the questions that follow a Name the type of relationship in: i Photograph W 1mark ii Photograph M 1mark b Explain your answer in a ii above 2marks c What is the importance of the relationship taking place in the photograph W 1mark d Using observable feature only explain two ways in which the flower is adapted for the activity taking place in photograph M 2marks e . I Give the biological term used to refer to the phenomenon captured in photograph W between organisms A and B towards C 1mark BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com ii State two implications of the phenomenon mentioned in d i above 2marks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com CEKENAS END OF TERM TWO EXAM 2023 231 3 BIOLOGY PAPER 3 PRACTICAL CONFIDENTIAL INSTRUCTIONS These instructions are to enable the head of institution and the teacher in charge of biology to make adequate preparations for 231 3 Biology Practical No one else should have access to this information either directly or indirectly. Each candidate requires the following 30 ml of solution K mixture of starch and albumin 3 ml of solution M3 enzyme diastase 3 ml of solution M4 boiled enzyme diastase Iodine solution 100ml 6 test tubes in a test tube rack Specimen X Thoracic vertebrae Test tube holder Means of timing Thermometer Water bath to hold two 100ml beakers simultaneously Two visking tubings each 6cm long and threads to tie their ends Two 100 ml beakers Access to Means of heating Sodium hydroxide solution 10 Copper II sulphate solution 1 Iodine solution Benedict s solutionBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com GATUNDU SOUTH JOINT EXAMINATIONS 2023 231 1 BIOLOGY PAPER 1 Theory 1. The diagram below shows an apparatus used during collection of specimen a Identify the apparatus 1mk b What is the use of the apparatus named above 1 mk 2.


I Give the biological term used to refer to the phenomenon captured in photograph W between organisms A and B towards C 1mark BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com ii State two implications of the phenomenon mentioned in d i above 2marks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com CEKENAS END OF TERM TWO EXAM 2023 231 3 BIOLOGY PAPER 3 PRACTICAL CONFIDENTIAL INSTRUCTIONS These instructions are to enable the head of institution and the teacher in charge of biology to make adequate preparations for 231 3 Biology Practical No one else should have access to this information either directly or indirectly. Each candidate requires the following 30 ml of solution K mixture of starch and albumin 3 ml of solution M3 enzyme diastase 3 ml of solution M4 boiled enzyme diastase Iodine solution 100ml 6 test tubes in a test tube rack Specimen X Thoracic vertebrae Test tube holder Means of timing Thermometer Water bath to hold two 100ml beakers simultaneously Two visking tubings each 6cm long and threads to tie their ends Two 100 ml beakers Access to Means of heating Sodium hydroxide solution 10 Copper II sulphate solution 1 Iodine solution Benedict s solutionBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com GATUNDU SOUTH JOINT EXAMINATIONS 2023 231 1 BIOLOGY PAPER 1 Theory 1. The diagram below shows an apparatus used during collection of specimen a Identify the apparatus 1mk b What is the use of the apparatus named above 1 mk 2. Students at Handege secondary school observed that when sodium chloride was poured onto grass the grass dried up. Explain this observation? 2mks 3. Explain why food is stored in an insoluble form in the cells of living things. 2mks 4. A Name the blood vessel that connects arteries to vein.


Explain how blood sugar level is maintained constant in human blood 2mks 15. A During a field trip a plant that had flowers drew the attention of a student. Name the division of the plant. 1mk b Students observed an animal with the following features Dorsoventrally flattened body One pair of legs per segment Poison claws on the head i Name the class to which the animal belongs. 1mk ii State the mode of feeding of the animal 1mk 16. How is mammalian skin adapted for excretion 3mks 17. The paddles of whales and the fins of fish adapt these organisms to aquatic habitats. A Name the evolutionary process that may have given rise to these structures. 1mk b What is the name given to such structures? 1mk 18. A patient with blood group A was involved in a road accident and required urgent blood transfusion. His relatives were invited to donate blood. A Name the compatible blood groups 2 marks b State why other blood groups were not compatible 2 marks 19. A . State two effects of Gibberellins on shoots of plants. 2mks b . Account for loss in dry weight of cotyledons in a germinating bean seed. 1mk . 20. Explain why a pregnant woman excretes less urea compared to a woman who is non pregnant. 2mks 21. Study the reaction below and answer the questions that follow. A What biological processes are represented by A and B? 2mks b Identify the product Y. 1mk c State the bond represented by X. 1mk 22. The oxidation state of a certain food is represented below by a chemical equation. 2C3 H 2O 2N 6O2 NH4 2 CO2 5CO2 5H2 O a Calculate the respiratory quotients RQ of the food substance. 2mks b Identify the food substrate 1mk BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com 23. An experiment was set to investigate a certain aspect of response. A seedling was put on a horizontal position as shown in figure M below.


2mks b Identify the food substrate 1mk BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com 23. An experiment was set to investigate a certain aspect of response. A seedling was put on a horizontal position as shown in figure M below. After 24 hours, the set up was shown in figure N. a Name the response exhibited by the shoot. 1mk b Explain the curvature of the shoot upwards. 3mks 24. During an accident a victim suffered injuries in the head. After the accident he lost his memory and was passing excessive amount of dilute urine. Suggest the part of the brain that was damaged in relation to: a Memory 1mk b Passing large amounts of dilute urine 1mk 25. Name the tissues whose cells are thickened with; a Cellulose and pectin 1mk b Lignin 1mk 26. State the function of the following structures found in the wall of the trachea. 3mks i Cilia ii Mucus iii Rings of cartilage 27. Name the organelle that would be most abundant in: i White blood cell 1mk ii Salivary glands 1mk 28. The diagram below represents a bone of a mammal a Identify the bone. 1 mark b Name the part marked X. 1 mark c Name the bone that articulates at the part labeled F. 1 mark d State two ways in which the bone is adapted to its function. 2 marks 29. A Under which of the following magnifications would one see a larger part of the specimen X 40 or X 500? Give a reason. 2 marks b State how magnification is worked out in a light microscope 1mark BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com GATUNDU SUBCOUNTY JOINT EXAMS 231 2 BIOLOGY PAPER 2 1.


1mk ii Suggest an identity of the enzyme used in the experiment 1mk b i Account for the observation made after 30 minutes 3mks ii Suggest a control experiment for the experiment above 1mk c Give TWO ways of increasing the rate of reaction in the visking tubing in order to have results of the experiment in less than 10 minutes 2mk 3. The diagrams shown below are of two organisms associated with human diseases a i Name the vector of parasite labelled P 1mk ii What is the survival advantage of the close association of the male and female of parasite P as shown in the diagram above? 1mk iii List TWO symptoms of the disease caused by P 2mks b i Name the parasite transmitted by the organism labelled Q 1mk ii Explain why only the female of organism Q transmit human diseases 1mk c Small fish can be used to control spread of human disease associated with Q. Explain. 2mks 4. A cross of red flowered plant and white flowerd plant produced plants with pink flowers. Using letter R to represent gene for red colour and W to represent white colour; a work out a cross between f1 plants. 4mks b Give the i Phenotypic ratio of f2 plants 1mk ii Genotypic ratio of f2 plants 1mk BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com c Name a characteristic in human which is controlled by multiple alleles. 1mk d Which is the biological term used to refer to the condition exhibited by f1 plants. 1mk 5. A State one economic importance of the following plants excretory products. 3mks i tannin ii quinine iii Caffeine b State two reasons why animals need elaborate excretyory system. 2mks c Describe how you can test for presence protein in urine. 3mks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com SECTION B 40 Marks Answer question 6 compulsory and either question 7 or 8 6.


2 marks 3. The photographs below are organisms found in a given ecosystem. Study them carefully and answer the questions that follow. BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com a During an ecological study in the ecosystem above ecologists established the biomass of the four organisms in the table below. Match the biomass with the organisms above to complete the table below. 2 marks Biomass Organism photograph 400 Kg 1000 Kg 100 Kg 600 Kg b Construct a possible food chain for the ecosystem above 2 marks c i Using a suitable scale, use the data provided to construct a suitable ecological pyramid for the above ecosystem. 5 marks ii Account for the shape of the pyramid above 2 marks d Give four major adaptations of specimen X that enable it to survive in the above ecosystem . 2 marks CONFIDENTIAL Question 1 - Half a piece of medium sized potato tuber labeled M - A small piece of liver fresh liver tissue 1cm x 1cm i.e 1 4kg for about 50 students - Wooden splint - Hydrogen peroxide about 10ml per student - Means of burning the wooden splint - Scalpel - Two empty boiling tubes per student Question 2 - 20 ml of concentrated salt solution in a beaker labeled Q per student - 20 ml of distilled water in a beaker labeled solution R per student NOTE: All photographs should be colour printedBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com NTIMARU SUB-COUNTY CLUSTER EXAMS 231 1 BIOLOGY PAPER 1 JULY AUGUST 2023 - 2 Hours 1. In a prolonged drought period, forage was scarce. It made animals reach out for higher forage and this way the giraffes got the stretched long necks. A What is the term used for a characteristic such as the long necks outlined? 1mk b What is the name given to the theory that describes the evolution of such structures like the long necks? 1mk c State and explain the limitation of the theory you named in b above. 2mks 2.


Calculate the total magnification of the microscope 2mks 10. Name the disease of the blood characterized by, a Abnormally large number of white blood cells 1mk b Crescent shaped hemoglobin 1mk 11. A State two roles of hydrochloric acid secreted by the stomach wall. 2mks b Name the cells that secrete the above component. 1mk 12. The diagram below shows various types of gene mutations. A Identify the type of gene mutation shown above. 2mks Mutation 1 Mutation 2 b Distinguish between gene and chromosomal mutations 2mks 13. If the ovaries of a woman are removed during the first four months of pregnancy miscarriage is very likely to occur. However if they are removed after the forth month pregnancy can proceed normally. Explain 3mks 14. State two reasons why anaerobic respiration yields less energy than aerobic respiration 2mks 15. State two reasons why fat is not an efficient substrate. 2mks 16. State two reasons why humans are not used as specimens for genetic studies 2mks 17. The diagram below shows two fused bones of a mammal. A Identify the fused bone 1mk b Name the: i Bone that articulates at the point labeled F 1mk ii The hole labeled G 1mk 18. I Define the term predation 1mk ii State three behavioral adaptations displayed by the prey to minimize predation 3mks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com 19. A shoot of a seedling exposed to light on one side bends towards the source of light as it grows. A Name the response exhibited by the shoot of the seedling 1mk b Explain how the bending towards the source of light occurs 3mks 20. The diagram below shows the position of an image formed in a defective eye. A Name the defect 1mk b Explain how the defect named in a above can be corrected 2mks 21. State three ways by which plants compensate for lack of ability to move from one place to another.


His dispute is incorrect given that he belongs to blood group A. Explain without using a genetic cross or a punnet square. 2marks b Haemophilia is a sex linked trait in humans caused by a recessive gene located in the X chromosome. A man with normal blood clotting marries a woman who also has normal blood clotting in the event of a cut. On getting offsprings, one of their sons turned out to be a haemophiliac. By the use of letter H for Normal blood clotting, illustrate the outcome of the haemophiliac son using a genetic cross. 4marks c Other than haemophilia state two sex linked traits in human. 2marks 2. A student set up materials in an experiment as shown below. Sugar a State the physiological process being investigated. 1mark b If the experiment set up was left over-night, state observation in the set up A and B. 2marks c Account for the observations in each set up. 3marks d If another experiment C was set such that nothing is placed in the potato cup, state and explain the results that would have been obtained. 2marks 3. The diagram below represents bread mould Rhizopus . Fresh potato Boiled Potato WaterBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com a Identify the part labelled A 1 mark b State the function of parts labelled C. 1mark c List two differences between Class chilopoda and diplopoda. 2marks Class chilopoda Class diplopoda d The diagram below represents a section obtained from a plant. Classify the plant from which the section was obtained under the following: 2marks i Division................................................................................................................................... ii Class ...................................................................................................................................... e Give two reasons for your answer in d ii above. 2marks 4. . The diagram below represents a simple respiratory pathway in cells. A Name the process marked X and Y. 2marks b State two differences between process X and Y. 2marks c State the name of substance B and condition under which it is formed. 2marks d Explain how body size affects the rate of respiration in animals. 2marks 5.


2marks c State the name of substance B and condition under which it is formed. 2marks d Explain how body size affects the rate of respiration in animals. 2marks 5. The diagram below shows structures of the bat wing and human arm. Wing membraneBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com a These structures are thought to have same ancestral origin. State one structural similarity and one adaptational difference between the two. I Structural similarity. 1mark ii Adaptational difference. 2marks b Give two other examples of structures in nature that show the type of evolution as in a above. 2marks c Distinguish between the terms chemical evolution and organic evolution . 2marks d What is the study of fossils? 1mark SECTION B 40 MARKS Answer question 6 compulsory and either 7 or 8 in the spaces provided . 6. The table below how the quantities of sweat and urine vary with external temperature. External Temperature 0 c 0 5 10 15 20 25 30 35 Urine cm3 h 100 90 80 70 60 50 40 30 Sweat cm3 h 5 6 10 15 30 60 120 200 a Using the same grid, draw graphs of quantities of urine and sweat produced against external temperature . 6marks b At what temperature is the amount of sweat and urine produced equal. 1mark c Account for the amount of sweat produced as the temperature rises. 3marks d Explain the observations made on the amount of urine produced as temperature rises. 4marks e Explain how the erector pili muscle help in temperature regulation when it is cold. 4marks f How does Anti diuretic hormone affect the amount of urine produced by a mammal per day. 2marks 7. Explain how various structural features of plants affects the rate of transpiration. 20marks 8. A . Describe what happens in the nervous system of a person who withdraws a finger from very hot object 10marks b . Describe the roles of the following plants hormones in growth and development of plants.


2 mks 18. A Beside venation, state two other external characteristics of leaves that can be used to classify plants. 2mks b How can floral parts be used to classify plants 2mks 19. A What is meant by the term seed dormancy? 1mk b State three causes of seed dormancy. 3mks 20. Explain why; a Mammalian testes are located to hang outside the body. 2mks b Four months after fertilization, ovaries can be removed from a human female, without terminating pregnancy. 2mks 21. State three structural differences between arteries and veins. 3 mks 22. What is the function of the following structure in the human reproductive organ? A Fallopian tubes. 1 mk b Epididymis. 1 mk c Scrotal sac 1mk 23. A State two ideas proposed by Lamarck s in his theory of evolution. 2 mks b Why is Larmark s theory not acceptable? 1 mrk BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.comBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com MUMIAS WEST JOINT EXAMINATION 231 2 BIOLOGY Paper 2 THEORY SECTION A 4OMKS Answer ALL the questions in this section in the spaces provided. 1. The diagram below represents a food web in a terrestrial ecosystem. A Which organism has the highest number of preys l mk b Construct food chains with snakes as tertiary consumers 2mks c State the trophic level occupied by hawks in the food chains constructed in b above lmk d Describe how capture-recapture method can be used in estimating the population of fishes in a lake. 4mks 2. Study the diagram below and answer the questions that follow.


A Which organism has the highest number of preys l mk b Construct food chains with snakes as tertiary consumers 2mks c State the trophic level occupied by hawks in the food chains constructed in b above lmk d Describe how capture-recapture method can be used in estimating the population of fishes in a lake. 4mks 2. Study the diagram below and answer the questions that follow. A Name the part labeled A and B 2marks b State the function of the part labeled C 2marks c How is the part labeled E adapted to its function 2marks d Identify the structure that perform the same function as one illustrated above in 2marks i Amoeba ii Fish BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.comBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com 3 a What is multiple allelism? 1mk b A pure breeding black male mouse was mated with a pure breeding brown female mouse. All the offspring had black coat colour. Explain the appearance of black coat colour in the offspring. 1mk i If the black parental mouse was mated with a mouse that is heterozygous for coat colour, work out the genotypic ratio of the offspring. Show your working. 4mks ii State two disorders in human beings that are as a result of chromosomal mutation. 2mks 4. A Explain what happens to excess amino acids in the liver of humans 3mks b Name two parts of human nephron which are only found in the kidney cortex. 2mks c i In what form is carbon ii oxide transported in blood. 1mk ii Explain why it may cause death 2mks 5. The diagram below indicates an organism that grows under shaded places with damp conditions. Study it and answer the questions that follow. A Name the division to which the specimen belongs. 1 mark b Name and state the functions of the parts labelled Q, R and S. 6 marks c Name the two body forms of the organism in its alternation of generation.


2marks . D i Account for the length of hind limb femur between day 3 and day 7. 3 marks ii Day 7 and day 10. 2 marks e State the hormones involved in the growth pattern represented by the graphs. 2 marks f State two advantages for metamorphosis in organisms. 2 marks 7 a Describe the structural adaptations of mammalian heart to its functions 10mks . B Explain the role of osmosis in organisms 10mks 8. Describe the movement of water from the soil up to the leaves and then into the atmosphere. 20 marks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com MUMIAS WEST JOINT EXAMS BIOLOGY 231 3 BIOLOGY PRACTICAL i a You are provided with specimen M. Peel off the epicarp. Scoop three spatulas full of the endocarp and place the portion into a clean beaker. Smash the specimen in the beaker using a glass rod. Add 20 ml of distilled water and stir using the glass rod to form solution M. Using the reagents provided carry out a food test to test for the food substance found in solution M. Spare the remaining solution to be used later. Fill the table below. Reducing sugar test Starch test Observation: Observation: Conclusion: Conclusion: 4mks b Movement of food molecules from the digestive system into the blood stream can be investigated using avisking tube. You have been provided with a 6cm visking tube. PROCEDURE : Soak the visking tube in water for afew minutes then open the visking tubing and tightly tie one end such that there should be no leakage. Fill the tubing with 5ml of solution M from the beaker and tie the remaining end. Ensure again there is no leakage. Rinse the outer surface of the visking tubing to remove any traces of the paste; Immerse visking tubing and its contents in distilled water in a boiling tube. Pour into the boiling tube distilled water such that the visking is fully immersed. Leave the set up undisturbed for at least 20 minutes. Carefully remove the visking tubing and its contents from the boiling tube.


Pour into the boiling tube distilled water such that the visking is fully immersed. Leave the set up undisturbed for at least 20 minutes. Carefully remove the visking tubing and its contents from the boiling tube. After 20 minutes carry out afood test again using the sample of water from the boiling tube in which the visking tube had been immersed. Reducing sugar test Starch test Observation: Observation: Conclusion: Conclusion: 4mks c i Why was the visking tube rinsed before the start of the experiment. 1mk ii Explain what has happened in b above at the end of the experiment. 2mks d Name the part of the digestive system that might be represented by the visking tube. 1mk e i Name the blood vessel that transports oxygenated blood from the part named d above to organ R in question 2 below . 1mk ii With reference to the visking tube provided state one observable feature that adapts the part named in d above to its function. 1mk BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com ii You are provided with a photograph of specimen R showing an organ from the body. You are also provided with a piece of specimen R. Study them and answer the questions that follow. SPECIMEN R. a i Name specimen R. 1mk ii label on the photograph the following parts. 3mks Gall bladder Aorta. Inferior venacava b Explain why malfunctioning of R leads impaired sugar regulation. 3mks c Cut specimen R into two equal pieces. Immerse one piece into aboilling tube. Add alittle water and boil it for five minutes. Label one boiling tube A. Label another boiling tube B. Using a pair of forceps remove the piece of R that has been boiled from the boiling tube and put it in the boiling tube labeled A. Take the remaining piece of R that was not boiled and put it into the other boiling tube labeled B. In each of the boiling tubes A and B add 10 ml of hydrogen peroxide respectively.


Using a pair of forceps remove the piece of R that has been boiled from the boiling tube and put it in the boiling tube labeled A. Take the remaining piece of R that was not boiled and put it into the other boiling tube labeled B. In each of the boiling tubes A and B add 10 ml of hydrogen peroxide respectively. I Record your observation A: 1mk B: 1mk ii Account for the observation in A: 2mks B: 1mks iii Which excretory function of specimen R is being investicated. 1mk iv State one disease that can affect specimen R. 1mk iii You are provided with specimens H and K. Observe the specimens keenly. A State two functions of specimen K. 2 marks b Name the division and class to which specimen H belongs. Division 1 mark Reason 1 mark Class 1 mark Reasons 2 marks c State three adaptations of specimen K for maximum photosynthesis. 3marks d Explain two ways in which specimen H is adapted for survival in its habitat. 2 marks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com MUMIAS WEST JOINT EXAMS BIOLOGY PRACTICAL CONFIDENTIAL Each candidate will require the following; 1. Empty 100ml 250ml beaker test tube rag 2. Distilled water 3. 4 boiling tubes 4. 10ml measuring cylinder 5. Stopwatch 6. Scalpel 7. Glass rod 8. 50ml plastic beaker 9. Spatula 10. Dropper 11. 4 test tubes 12. Specimen R - Asmall piece of liver 13. Specimen H - complete grass 14. Specimen K - Bipinnate leaf 15. Specimen M - Half portion of ripe banana 16. 8cm visking tube 17. 2 pieces of thread 18. Two labels Access to: a Source of heat b Benedict s solution c Iodine solution NOTE: THE PHOTOGRAPH SHOULD COLOURED EASTERN CLUSTER EVALUATION - 2023 BIOLOGY PAPER 1 TERM 2, 2023 1.


8cm visking tube 17. 2 pieces of thread 18. Two labels Access to: a Source of heat b Benedict s solution c Iodine solution NOTE: THE PHOTOGRAPH SHOULD COLOURED EASTERN CLUSTER EVALUATION - 2023 BIOLOGY PAPER 1 TERM 2, 2023 1. State the name given to the study of: a Fish 1 mark b Cell 1 mark 2. Student classified a lion as follows: Kingdom : Animalia Phylun: Mammals Specific name: Panthera leo Identify three mistakes in her work. 3 marks 3. State why it is important for plants to lose water into the atmosphere. 3 marks 4. A Name the disease that causes: i Thickening and hardening of arteries 1 mark ii Formation of clot in blood vessels 1 mark b In a certain person, blood took a long time to clot after a cut. What vitamin deficiency was the person likely to have been suffering from? 1 mark BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com 5. A Name the causative agents of the following diseases. I Pulmonary tuberculosis 1 mark ii Whooping cough 1 mark b In an experiment to analyse a sample of air, a J tube was used to find out the amount of carbon IV oxide and oxygen in the sample. The length of the sample air in J- tube was 8cm and after mixing it with some sodium hydroxide solution for some minutes, the length was reduced to 7.6cm. When pyrogallic acid was also made to mix with the sample of air for some minutes, the length reduced further to 6.6cm. A What was the percentage of: i Oxygen in the air sample? Show your working 2 marks ii Carbon IV oxide in the air sample? Show your working 2 marks b What was the role of: i Sodium hydroxide solution 1 mark ii Pyrogallic acid 1 mark . 6. A Use the data given to answer the questions that follow. Organism Number Lion 10 Grass 1000 Antelope 200 i Construct a possible food chain.


6. A Use the data given to answer the questions that follow. Organism Number Lion 10 Grass 1000 Antelope 200 i Construct a possible food chain. 1 mark ii Construct a pyramid of numbers from the given data. 2marks b What is the role of the following bacteria in the nitrogen cycle? I Nitrobacteria 1 mark ii Clostridium 1 mark iii Thiobacillus denitrificans 1 mark 7. It was observed that when maggots are exposed to light, they move to dark areas. On the other hand, chlamydomonas and spirogyra move towards light. A Name the type of response shown by the organisms. 1 mark b Give one advantage of the response shown by chlamydomonas and spirogyra. 1 mark c Shoot tips are observed to bend towards light coming from one direction. I Name the type of response. 1 mark ii Explain how this response occurs. 4 marks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com 8. A State two factors that cause seed dormancy. 2 marks b What is the role of the following hormones in insect metamorphosis? 2 marks i Juvenile hormone ii Ecdysome 9. A Name any two salivary glands. 2 marks . B Name two digestive enzymes secreted in their inactive form. 2 marks 10. Draw a trifoliate dicotyledonous leaf that has serrated margin and rounded tip apex. 3 marks 11. Two normal parents gave birth to a son later in his years they found out that he always picked up a red jersey when going to school yet the school uniform was a green jersey. They tried to explain to the boy the mistake but the boy could not understand. I Identify the generic disorder the boy was suffering from. 1 mark ii The possible genotype of the parents. 2 marks iii Using a genetic cross determine the boy s genotype. 4marks 12. The figure below illustrates two cells obtained from two different organisms.


2 marks iii Using a genetic cross determine the boy s genotype. 4marks 12. The figure below illustrates two cells obtained from two different organisms. A Give the name used to: i Cell J 1 mark Reason: 1 mark ii Cell R: 1 mark Reason: 1 mark b State the function of the following parts of a microscope i Mirror 1 mark ii Condenser 1 mark iii Stage 1 mark 13. A i What is respiratory quotient. 1 mark ii State its importance. 2 marks b State two factors affecting the rate of respiration. 2 marks 14. State three methods of fossil formation. 3 marks 15. A Name two types of involuntary muscles in mammals. 2 marks b Differentiate between a tendon and ligament. 1 mark c Name two types of synovial joint. 2 marks 16. Explain why: a Four months after fertilization, ovaries can be removed from human female without terminating pregnancy. 2 marks b The chances of fertilization are higher in organisms having internal fertilization. 2 marks 17. List three symptoms of diabetes mellitus. 3 marks 18. State three ways in which osmosis is significant to plants. 3 marks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com EASTERN CLUSTER EVALUATION - 2023 231 2 BIOLOGY PAPER 2 THEORY SECTION A. 1. A What is accommodation? 1mk b Describe the sequence of events that occur in the eye for one to be able to see clearly i a distant object 4mks ii if one moved from a dim lit room to bright light. 3mks 2. The following are short messages sms on cell phone communication between Mrs. Mkenzie and her husband. They can be used as analogies of gene mutation Intentended message Actual message 1. I want a drive I want a driver 2.


Mkenzie and her husband. They can be used as analogies of gene mutation Intentended message Actual message 1. I want a drive I want a driver 2. Yesterday was my shopping day Yesterday was my hopping day 3 My skirt was stolen My shirt was stolen 4 Tomorrow I will be visiting my team Tomorrow I will be visiting my mate a For each of these messages identify the type of gene mutation illustrated 4mks b State one example of chromosomal mutation that lead to i Change in chromosome structure 1mk ii Change in chromosomal number 1mk c Explain why genetic counseling is termed as one practical application of genetics 2mks 3. A What is active transport? 1mk b State three factors that increase the rate of active transport. 3mks c Give four roles of active transport in living organisms. 4mks 4. Three tubes each containing 1ml saliva and 1ml water were incubated in water baths at different temperatures as shown in the diagram below for 30 minutes. Another one tube containing 1ml starch solution was incubated for the same length of time in each water bath. The contents of the two tubes in each water bath was then mixed and incubated for further 30 minutes. The content of each tube was then tested for starch using iodine solution. A What was the aim of the experiment? 1 mark b Why was it necessary to incubate the tubes for 30 minutes before mixing their contents? 1 mark c State the colour changes you would expect to observe after adding iodine solution. 3 marks d Account for the expected observations. 3 marks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com 5. Below is a diagram of a sperm cell. A Identify parts labeled X and Y. 2 marks b Explain how parts W and Z adapt the cell to its function. 4 marks c Using letter P identify or label on the diagram the part of the cell rich in DNA. 1 mark d State the function of part X. 1 mark 6. An experiment was carried out whereby three healthy rats were fed on equal amounts of glucose. After half an hour, the glucose concentration per ml.


1 mark 6. An experiment was carried out whereby three healthy rats were fed on equal amounts of glucose. After half an hour, the glucose concentration per ml. Of blood was measured at 15 minutes intervals for three hours. The following results were obtained. 0 min 15 min 30 min 45 min 60 min 75 min 90 min A 0.800 0.774 0.715 0.680 0.650 0.595 0.555 B 0.745 0.695 0.695 0.660 0.635 0.600 0.545 C 0.795 0.695 0.665 0.635 0.590 0.550 0.495 Mean 0.780 0.72 0.691 - 0.625 - 0.532 a i Calculate the mean concentration of glucose in mg per ml of blood at 45 and 75 minutes. Record your answer on the table. 2 marks ii On the graph paper provided, plot a graph of the mean glucose concentration against time. 6 marks iii What was the mean glucose concentration in the blood after 37.5 minutes? 1 mark iv Give a reason why it was necessary to use three rats in the experiment instead of one. 1 mark v Why was the initial concentration of glucose in the rats not the same? 2 marks vi Account for the difference in mean glucose concentration during the period. 3 marks b Give two reasons why glucose is the main respiratory substrate. 2 marks c Give three ways in which glucose is assimilated in the body. 3 marks 7. A What assumption are made when using the captured recapture method in estimating population of animals. 5 marks b Describe how you would use the capture recapture method to estimate the population of fish in the school pond. 13 marks c State two other methods of estimating population. 2 marks 8. Describe the role of the liver in homeostasis. 20mks Glucose conc.


2 marks 8. Describe the role of the liver in homeostasis. 20mks Glucose conc. Mg ml RatsBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com EASTERN CLUSTER EVALUATION - 2023 231 3 BIOLOGY PAPER 2 PRACTICAL 1. Cut 2 pieces of specimen Q provided; each 4 cm long. Split each half-way at the center cut about 2 cm as shown below on the diagram. You are provided with 2 petri dish S and T. Place one piece on petri dish S, the other on Petri dish T. To S, add distilled water, and T add 25 sucrose solution. Leave the set-up for 15 minutes. Record observation on the table below 2mks Petri-dish Observation S T i Explain the observation in S , T 4mks ii Feel both Q in S and T between 2 fingers and record observations. 2mks iii Explain the significance of the conditions in S to flowering plants. 2mks iv Explain what would happen to red blood cells when placed to 23 sucrose solution. 2mks 2. A student collected a number of organisms as shown below. She constructed a dichotomous key as shown below 4cm 2 cm K7 K8BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com Dichotomous key: 1. A Organism with limbs . Go to 2 b Organism without limbs ... go to 3 2. A Organism with three pairs of limbs .. go to 4 b Organism with more than three pairs of limbs go to 5 3. A Organism with calcareous shell Mollusca b Organism with horny scales on body ...Ophidia 4. A Organism with wings .Diptera b Organism without wings . .Isoptera 5. A Organism with four pairs of limbs . Go to 6 b Organism with more than four pairs of limbs .. go to 7 6.


1mk Significance of this condition 1mk d Account for differences in length of R and S. 1mk e Name the response shown by seedling Q and explain how it occurs Response: 1mk Explain 2mks f State the type of germination 1mk Reason 1mk EASTERN CLUSTER EXAMS BIOLOGY 231 3 CONFIDENTIAL 1. 2 pieces of 4cm long stalk of young bidens pilosa or Tradescantia or zebrina. Means of labelling 2 3 empty petri dishes Distilled water 25 sucrose solutionBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com BOKAKE EXAMINATION 231 1 BIOLOGY PAPER 1 THEORY 1. Name the reagent used for testing presence of 3 marks a Starch b Reducing sugars c Vitamin c 2. State the processes which occur in each of the following organelles. 2 marks a Chloroplast b Mitochondrion c Ribosomes 3. A student observed a specimen through a light microscope. He used the objective lens marked X40.If he indicated the magnification of the image as x 400, what was the eye - piece magnification? Show your working . 3 marks 4. State the function of the following in mammalian trachea. 3 marks a Rings of cartilage b Mucus c Cilia 5. A What do you understand by the term biological control? 1 mark b Explain why all the energy produced by producers does not flow to the tertiary consumers. 2marks 6. Name any three forces that maintain the transpiration stream 3 marks 7. Give the form in which the following gases are transported in blood. 3 marks a Oxygen b Carbon IV oxide. C Carbon II oxide 8. A Name the main group of organisms which comprise the Kingdom Monera. 1mark b State any three ways in which the organisms named in 8 a above affect human lives.


C Carbon II oxide 8. A Name the main group of organisms which comprise the Kingdom Monera. 1mark b State any three ways in which the organisms named in 8 a above affect human lives. 3marks c State the main characteristics of Monera which distinguish it from all other kingdoms. 1 mark 9. Seed germination is affected by certain plant growth regulators. Describe two actions of gibberellins during seed germination 2marks 10. Why is it necessary for an athlete to breathe heavily after running? 2 marks 11. State ways in which the following diseases can be prevented a Typhoid 2 marks b Malaria 2 marks 12. A person fell from the third floor of a storey building and had part of his brain damaged indicate the part of the brain damaged if the person suffers from the following 4marks i Loss of memory and speech ii Inability to regulate body temperature iii Irregular heartbeat and breathing iv Inability to maintain proper body balance and posture 13. A Name the main product of the dark stage of photosynthesis. 1mark b What is the role of chlorophyll during photosynthesis 2mark 14. Name three mechanisms that prevent self-pollination in flowers that have both male and female parts. 3 marks 15. State three applications of anaerobic respiration. 3 marks 16. What is the significance of highly folded inner membrane of a mitochondrion? 2 marks 17. Why is it necessary for blood from the gut to pass through the liver before joining general circulation? 2 marks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com 18. A person s urine tested positive for reducing sugars. A Name the type of sugar present in the urine. 1mark b Name the gland and the hormone which failed to control the above condition. 2marks Gland Hormone c Which disease was the person suffering from? 1mark 19. State two roles played by the process of reproduction. 2marks 20. A Name the genetic disorder in humans that is characterized by inability of blood to clot 1mark ..


State two roles played by the process of reproduction. 2marks 20. A Name the genetic disorder in humans that is characterized by inability of blood to clot 1mark .. b A female human was found to have an extra sex chromosome in her cells. I Give the total number of chromosome in the male individuals cells 1mark ii Explain the possible causes of this condition 2marks iii State two physical characteristics observed in the male individual with such a condition 2marks 21. A State ways in which molars are adapted to their functions. 2marks 22. A Explain why fossil records as evidence of organic evolution are usually incomplete 3 marks b Name the evidence of organic evolution exhibited by occurrence of similar amino acid molecules in a range of organisms 1mark 23. The diagrams below represent germination of a certain seed a Name the type of germination exhibited by the seedling above 1mark b Name the region labeled x 1mark c Explain how the part labeled x of the seedling straightens after exposure to sunlight. 3marks 24. State any one characteristic common to all living organism? 1mark 25. A State one event that occurs in prophase of meiosis I which does not occur in prophase of mitosis. 1 mark b What are the results of the above phenomena? 2 marks 26. Explain why growing grass die a few days when salt is sprinkled on it. 3marks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com BOKAKE JOINT EXAMS 231 2 BIOLOGY PAPER 2 THEORY END OF TERM 2, 2023 SECTION A 40 MARKS 1. The diagram below illustrates circulation in certain organs of the mammalian body. A Identify the blood vessels represented by A, B and C. 3mks b Explain why blood from the small intestines goes to the liver before it goes to any other organ of the body. 2mks c Compare the blood in vessels B and C 1mk B - C - d Outline how a glucose molecule in vessel A finally reaches the heart. 2mks 2. The diagram below represents a section through a human tooth.


3mks b Use information from the table to predict the concentration of a sucrose solution isotonic to the cells in the tulip stem. 1mk c i Give the term which would be used to describe the cells in the tulip stem after immersion in a solution with a sucrose concentration of 0.7 moles per litre. 1mk ii Draw the appearance of a cell from the tulip stem after immersion in a solution with a sucrose concentration of 0.7 moles per litre. 2mks d State one role of the process being investigated in plants 1mk 5. A How many sex chromosomes are there in each human somatic body cell. 1mk b What is meant by the term sex-linkage? 1mk c Haemophilia is due to a recessive gene. The gene is sex linked and located on the X chrosome. In a family where both parents were normal, one of the sons was haemophiliac. I Using letter H for normal blood clotting gene, work out the genotype of the children. 4mks ii What is the probability of a child born by this couple being a boy and haemophiliac. 4mks d Explain why haemophilia is more common in males than in females. 1mk BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com SECTION B 40MARKS Answer questions 6 compulsory and either question 7 or 8: 6. The mean dry weight in milligrams of germinating barley grains was worked out for whole grain, endosperm and the embryo. The means were determined at two day intervals for twelve days. The results are shown in the table below; Time in days Dry weight of whole grain mg Dry weight of endosperm mg Dry weight of embryo Mg 0 49 45 6 2 46 42 6 4 44 35 9 6 42 24 17 8 40 12 25 10 41 8 32 12 45 8 40 a Using the same axes, draw graphs for dry weight of endosperm, embryo and the total dry weight against time.


The mean dry weight in milligrams of germinating barley grains was worked out for whole grain, endosperm and the embryo. The means were determined at two day intervals for twelve days. The results are shown in the table below; Time in days Dry weight of whole grain mg Dry weight of endosperm mg Dry weight of embryo Mg 0 49 45 6 2 46 42 6 4 44 35 9 6 42 24 17 8 40 12 25 10 41 8 32 12 45 8 40 a Using the same axes, draw graphs for dry weight of endosperm, embryo and the total dry weight against time. 7mks b What was the average dry weight of the embryo on day 9? 1mk c Account for the dry weight of; i Endosperm from day 0 to 12. 4mks ii Whole grain from day 0 to 12. 4mks d Other than water which other factors are necessary for germination. 2mks e Name the two types of germination. 2mks 7. A Describe the mechanism of opening and closing of the stomata using the following theories. 12mks a Photosynthetic theory. B Starch sugar inter-conversion theory. C The potassium ion theory. B Explain how respiratory surfaces in animals are adapted to their functions. 8mks 8. A Define pollution. 2mks b Describe water pollution under the following:- i Causes. 6mks ii Effects of pollutants on plants and animals. 6mks iii Methods of controlling pollution. 6mks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com BOKAKE EXAMINATON 231 3 BIOLOGY PAPER 3 PRACTICAL 1. You are provided with solution M, Dilute Hydrochloric acid ,DCPIP, Benedict s solution, 1 copper II Sulphate solution and 10 sodium hydroxide solution. Add 2m1 of hydrochloric acid to solution M and Shake.


6mks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com BOKAKE EXAMINATON 231 3 BIOLOGY PAPER 3 PRACTICAL 1. You are provided with solution M, Dilute Hydrochloric acid ,DCPIP, Benedict s solution, 1 copper II Sulphate solution and 10 sodium hydroxide solution. Add 2m1 of hydrochloric acid to solution M and Shake. Filter the mixture using the filter paper and filter funnel into a boiling tube provided. Wash the residue from the filter paper into a beaker. Using the reagents provided carry out food tests on the residue and filtrate. 15 marks a Residue Food substance being tested for Procedure Observation Conclusion REDUCING SUGARS VITAMIN C PROTEINS b Filtrate Food substance being tested for Procedure Observation Conclusion REDUCING SUGARS VITAMIN C PROTEINS c Account for the observation in a and b above. 2mks d The physiological process demonstrated above occurs in all living things. Name two important processes in animals that depend on it. 2mks 2. You are provided with specimen R and S a i Give a reason why both R and S are fruits. 1mk ii Why is R also reffered to as a seed? 1mk iii Tabulate any two differences between specimen R and S 2mks Specimen R Specimen S b Using a blade provided; carefully make transverse section of specimen S. i Make a labelled diagram of the cut section. Label any three parts. 4mks ii Name the type of placentation in S .Reason 2mks iii What is the likely agent of dispersal of S? Reason 2mkBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com 3. The photograph below is of mammalian organ a i. Name the basic functional units of the organ. 1mk ii State any function of the organ above. 1mk b Name the parts labelled- A, B C 3mks c How is the blood vessel E adapted its function.


A What is sex linkage? 1mark b Name two sex linked traits in Y chromosome in humans 2marks 10. A Explain why Lamarck s theory of evolution is not accepted in modern science 2marks b Give two examples of natural selection in action 2marks 11. Below is a diagram of an organelle that is involved in aerobic respiration a Name the organelle 1mark b Identify the parts labeled A and B 2marks c What is the purpose of in- folding in part labeled D 1mark d Give the mechanical compound which is formed in the organelle and forms the immediate source of energy 1 mark BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.comBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com 12 i Suggest the significance of the following adaptations in bony fish; Flexible vertebral column 1mark Presence of a swim bladder 1mark ii State two features which reduce resistance in fish during swimming 2marks 13. In an experiment on respiration, a mouse was observed to have inhaled 200cm 3 of oxygen and exhaled 199.75 cm 3 of carbon IV oxide in ten minutes. I Calculate the respiratory quotient for the activity in the experiment 2marks II Suggest the food substrate that was broken down 1mark 14. A Explain why malaria cannot be transmitted through blood transfusion 2marks b Explain the significance of the following with respect to ecosystem Decomposers 1mark Predators 1mark 15. State three ways in which seed dormancy benefits a plant 3marks 16. A Explain why maize stalks do not undergo secondary growth yet they increase in girth 3marks b State two characteristics of meristem tic cells 2marks 17. I Explain why two species cannot occupy the same niche 2marks Ii Name the bacteria found in root nodules of leguminous plant 1mark 18. A What are the roles of testes in the mammalian reproductive system? 2marks b Explain why female frogs produce large number of eggs 2marks 19.


I Explain why two species cannot occupy the same niche 2marks Ii Name the bacteria found in root nodules of leguminous plant 1mark 18. A What are the roles of testes in the mammalian reproductive system? 2marks b Explain why female frogs produce large number of eggs 2marks 19. A Differentiate between gaseous exchange and respiration 2marks b State two characteristics of a respiratory surface 2marks 20. Study the diagram below and the answer questions below i Name compound X 1mark ii State the role played by compound X in small intestine 1mark ii Other than trypsin, name two other enzymes produced in precursor form 2marks iii State the role played by compound X in the stomach 1mark 21. Name the organelle that perform each of the following Protein synthesis 1mark Transport of cell secretions 1mark 22. Name the type of muscle found in human heart 1mark BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com KIHARU KAHURO 231 1 BIOLOGY PAPER 2 SECTION A 1. In an experiment to investigate the rate of reaction indicated by the equation. C12 H22 O11 C6 H12 O6 C6 H12 O6 Sucrose fructose glucose It was found out that for products fructose and glucose to form, substance K was needed. Temperature was maintained at 37oC , when substance L was added , the reaction slowed and then stopped. A Suggest the identity of the substances K and l 2marks b Other than temperature, state three factors that increase the rate of reaction 3marks c Explain how substance L slowed the rate of reaction 2mks d What type of reaction is represented by the equation 1mark 2. A Study the diagram below that represents a plant in division Bryophyta i Name the parts Labeled Q and R 2 marks ii State two functions of part T 2marks b During a practical activity , form three students of Bahati secondary collected a specimen whose drawing is shown below during a class activity . State the phylum and class , that the organism belongs giving a reason for each case based on observable features only .


A Suggest the identity of the substances K and l 2marks b Other than temperature, state three factors that increase the rate of reaction 3marks c Explain how substance L slowed the rate of reaction 2mks d What type of reaction is represented by the equation 1mark 2. A Study the diagram below that represents a plant in division Bryophyta i Name the parts Labeled Q and R 2 marks ii State two functions of part T 2marks b During a practical activity , form three students of Bahati secondary collected a specimen whose drawing is shown below during a class activity . State the phylum and class , that the organism belongs giving a reason for each case based on observable features only . Phylum 1mark Reason 1mark Class 1mark Reason 1mark BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com 3. The diagram represents a set up to investigate the conditions necessary for seed germination . The set up was left or 7 days ii What conditions were being investigated in the experiment? 2marks iii Account for the for the expected results in each set up after 7 days A 2marks B 2marks C 2marks 4. The diagram below illustrates circulation in certain organs of the mammalian body . A Identify the blood vessels represented by: A, B C 3marks b Explain why blood from the small intestines goes to the liver before it goes to any other organ of the body. 2marks c Compare the blood in vessel B and C 1mark d Outline how a glucose molecule in vessel A finally reaches the heart. 2marks 5. Haemophilia is a sex linked characteristics caused by a recessive gene carried on the X chromosome. A carrier woman marries a normal man. Use letter H to represent the dominant gene a Work out the phenotypes of F1 generation show your working 5marks b What is the probability of couple getting b a hemophiliac son?


1mark ii Which process in the body is illustrated above? 1mark iii State the part of the body where the above process takes place. 1mark iv State two functions of substance B in the body. 2marks v Name two diseases of the circulatory system caused by excess cholesterol in the food. 2marks b The photograph below an the plants adopted to difficult habitats. Examine them. I Which of the plants are adapted to arid conditions. 2marks ii Give three observable features that enable the plant you have stated in a i above to survive in the arid regions. 3marks iii State three other adaptive feature not observable in the diagram in the photograph of the plants you state in a i above. 3marks iv Give the term used for plants that are adapted to arid and semi-arid conditions. 1mark Q3. You are provided with an actual specimen labeled D. Study it and answer the questions that follows: a State the class from which specimen D was obtained and give two reasons for you answer. Class. 1mark Reason. 1mark b State two observable features that adopt specimen D for gaseous exchange. 2marks c Account for the following features of the specimen D. i Extensive network of veins. 1mark ii Tough leaf blade. 1mark ii Strong and extended petiole. 1mark BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com d Explain why the following procedures would be necessary during the preparation of sections for observation. I Putting the sections in water on a Petridis. 1mark ii Using a sharp scalpel razor blade. 1mar iii Cutting very thin sections. 1mark KIHARU KAHURO BIOLOGY PP3 CONFIDENTIAL, TERM 2 2023 A Specimens i Specimen H Mature orange fruit ii Specimen D Kale sukumawiki leaf with petiole OTHERS 1. Six test tubes per student 2. Scapel Razor blade 3. White tile 4. Droppers 6. Source of heat B Chemical and Reagents 1. DCIPIP 2.


Droppers 6. Source of heat B Chemical and Reagents 1. DCIPIP 2. Iodine solution 3. Benedict s solution 4. About 3cm3 of substance B Olive oil 5. About 20cm2 NaHCO3BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com LUGARI CONSTITUENCY -MOCK 1 231 1 BIOLOGY PAPER 1 JULY AUGUST 2023 1. Study the diagram below showing a portion of an onion epidermis that had been irrigated with a certain solution X. a In one word describe the condition of the cells 1mk b Describe the process that lead to the condition named above. 3mks 2. The following reaction may proceed in forward or backward direction Glucose fructose sucrose water. A What term is used to refer to the backward reaction. 1mk b In which part of alimentary canal does the backward reaction occur? 1mk c Name the enzyme that catalyzes the backward reaction. 1mk 3. The diagram shown below represents a nucleus a State the role of the organelle labelled Q 1mk b Name a Kingdom whose members lack structure labelled P 1mk c Which is the general term given to organisms whose cells have structure P? 1mk 4. After fertilization of an ovule, which parts develops into: - a Testa 1mks b Endosperm 1mk 5 a Explain two roles of diffusion in human beings. 2mks B i Name the process through which a plant takes up some mineral ions against a concentration gradient. 1mk ii State two factors that may affect the process named in b i above. 2mks c Distinguish between haemolysis and plasmolysis. 1mk 6. An insect landed on a leaf of an insectivorous plant. Consequently, the leaf closed with its spines interlocking trapping the insect inside it. Name the response exhibited by the leaf. 1mk p QBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com 7. The figure below represents a plant.


Name the response exhibited by the leaf. 1mk p QBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com 7. The figure below represents a plant. A State the division it belongs to. 1mk b Label the parts labeled a b 2mk c State the role of part labeled d in the life cycle of the organism. 1mk 8. State any two adaptations of the cardiac muscle that enable it to undergo systole. 2mks 9. A Why are carbohydrates and not lipids the first choice respiratory substrates? 2mks b 2C57H110O6 163O2 114CO2 110H2O Energy. Calculate the RQ from the equation in c above. 2mks 10. Below is a diagram of a group of cells of a specific tissue. I Name the tissue 1mk ii This tissue lines the trachea and bronchi. Suggest its function in these structures. 1mk 11. Study the flow chart below which represents a physiological process in mammals A i Name blood components represented by X. 1mk ii What is the significance of product represented by Z. 2mks b Under what condition is thrombokinase released by the platelets? 1mk 12 a Explain what happens to excess amino acids in the liver of humans. 3mks b Which portions of the human nephron are only found in the cortex? 1mks BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.comBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com 13. A potted plant is transferred from outside on a sunny and windy day, to a dark room. A Briefly explain the effect this is likely to have on: i The rate of loss of water from its leaves. 3mks ii The rate of water absorption. 2mks 14. Give a reason why urine of a mammal does not contain amino acids. 1mks 15. A In what form is energy stored in muscles? 1mk b State the role of insulin in human body.


Below is a drawing of a cell. A With two reasons, identify the cell. 2mks Identify. ---------------------. Reasons: b Which of the three structure X, Y and Z speeds up transmission of the impulse. 1mk 22. A Name the pigment that protects humans from the negative effect of Ultraviolet lights. 1mk b Explain how sunlight contributes to stronger bones and teeth in human beings 2mks 22. A State two structural differences between skeletal muscles and smooth muscles. 2mks Skeletal muscle Smooth muscle i ii b What are antagonistic muscles? 1mk BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.comBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com 23. Name the substrates for the following enzymes i Carbonic anhydrase . 1mk ii Cholinesterase . 1mk 24. A tilapia fish has a full length of 300mm but measures 200mm from the mouth tip to its anus. Determine the tail power of the fish 2mks 25. State the differences between cones and rods in terms of the following 2mks Feature Cone Rod Visual acuity Photochemical 26. Impulse transmission across a synapse is in one direction. Explain 2mks 27. The diagram shown below represents a section of the vertebral column a Name the part labelled S 1mk b State TWO ways in which part T is important to movement in human beings 2mks 28. Give TWO features that make modern man to be more adaptable to the environment 2mks LUGARI CONSTITUENCY EXAM 231 2 BIOLOGY PAPER 2 THEORY 1. The flow chart below shows a process in a plant and animal cell T SBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com a Why is this process necessary in living organisms 3 marks b i Name the process labelled X 2 marks ii Name the part of the cell where process X occurs 1 marks c Name products A, B 2marks 2. .


Give TWO features that make modern man to be more adaptable to the environment 2mks LUGARI CONSTITUENCY EXAM 231 2 BIOLOGY PAPER 2 THEORY 1. The flow chart below shows a process in a plant and animal cell T SBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com a Why is this process necessary in living organisms 3 marks b i Name the process labelled X 2 marks ii Name the part of the cell where process X occurs 1 marks c Name products A, B 2marks 2. . A The bar charts show the percentages of a human population with each type of blood group and the percentages of a cattle population with and without horns. Which type of variation is shown in each population? 1mark Human: Cattle: b Albinism lack of skin pigmentation in humans is caused by two recessive alleles. A phenotypically normal non-albino couple have three children; the first two are non-albino, the third is an albino. In your answer, use A for the dominant allele and a for the recessive allele. I What are the genotypes of the parents? 1mark ii Is there a possibility that their next child will be an albino? Explain your answer 2 marks iii The albino child eventually marries a non-albino whose father was an albino. What is the probability that their first child will be an albino? Show all working. 4marks 3. The diagram below shows structures of the bat wing and human arm. BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com These structures are thought to have same ancestral origin. A State one structural similarity and one adaptational difference between the two. I Structural similarity. 1 mark ii Adaptation difference. 2 marks b Give two other examples of structures in nature that show the type of evolution as in a above. 2 marks c Distinguish between the terms chemical evolution and organic evolution . 2 marks d What is the study of fossils called? 1 mark 4.


8mks b Account for the shape of the curve of fresh weight between: i 2 10 weeks. 2mks ii 12 16 weeks. 2mks c Suggest why dry weight remains constant after week 14. 2mks d Describe how the dry weight of the maize could have been determined at various times. 3mks e State two advantages and one disadvantage of fresh weight as a measure of growth. 3mks 7. Describe how the leaves of mesophyte are suited to their function 20marks 8. Describe the nitrogen Cycle 20 marks LUGARI CONSTITUENCY JET EXAM BIOLOGY PAPER 3 PRACTICAL 1. You are provided with a specimen labelled J. a With reasons identify the organ of a plant represented by J. 1mk Reasons 2mks b Using observable features only identify the class to which J belongs. Class 1mk Observable features. 1mk BIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com a c In a previous experiment the lower epidermis and the upper epidermis were peel off, the number of stomata was determined using a microscope at high power objective. The results obtained are recorded in the table below. Arrange number of stomata in the field of view Lower epidemis Upper epidermis 30 13 1 Account for the average number of stomata on the upper and lower side of specimen J. Upper epidermis. 3mks Lower epidermis. 3mks 2 You are provided with photographs of: Specimen SI mango fruit Specimen T1 Garden pen pod U S1 TI a Specimen SI was cut longitudinally. The photograph below shows one half S1 b c d v w XBIOLOGY PAPER 1, 2 3 www.freekcsepastpapers.com i Name the parts labelled a,b,c,d and e 5mks Study the photographs of specimen T1 and name the parts labelled u,v,w,x ,y and z labeled 4mks iii Identify the type of presentation in each fruit.