1. 1989 Q6 P1
The diagram below represents a mammalian bone
(a) State the functions labelled K and L
(b) State the region of the body in which the bone is found
2. 1991 Q1 P1
State two ways in which skeletal muscle fibers are adapted to their functions
3. 1991 Q5 P1
The diagram below shows the arrangement of bones and muscles in a human arm
1. 1989 Q13 P1
In an experiment, a variety of garden peas having a smooth seed coat was crossed with a variety with a wrinkled seed coat. All the seeds obtained in the f generation had a smooth seed coat. The f generation was selfed. The total number of f2 generation was 7324.
(a) Using appropriate letter symbols. Work out the genotype of the f1 generation
(b) From the information above, work out the following for the f2 generation
2. 1990 Q2 P1
The figure below is a structural diagram of a portion from anucleic acid stand.
1. 1989 Q7 P1
State the difference between Lamarckian and Darwinian theories of evolution.
2. 1991 Q17 P1
(a) What is meant by natural selection
(b) Describe the natural selection brings about adaptation of a species to its Environment
3. 1992 Q5 P1
Two populations of the same species of birds were separated over a long period of time by an ocean. Both populations initially fed on insects only. Later it was observed that one population fed entirely on fruits and seeds, although insects were available.
1. 1989 Q9 P1
Explain why several auxillary buds sprout when a terminal bud in a young tree is
2. 1990 Q11 P1
In an experiment, a group of students set up four glass jars as shown in the diagram
below. Jar A, B and C were maintained at 25 for 7 days, while jar D was maintained at
0 for the same period of time.
EXCRETION AND HOMEOSTASIS
EXCRETION AND HOMEOSTASIS
1.1990 Q7 P1
(a) Explain why the body temperature of a healthy human being must rise up to 390C on a humid day.
(b) In an experiment a piece of brain was removed from a rat. It was found that the rat had large fluctuations of body temperature. Suggest the part of the brain that had been removed.
2. 1991 Q16 P1
(a) Explain how urea is formed in the human body
(b) Describe the path taken by urea from the organ where it is formed until it leaves the human body
3. 1992 Q4 P1
(a) Explain why sweat accumulates on a person’s skin in a hot humid environment.
(b) Name the specific part of the brain that triggers sweating
4. 1992 Q10 P1
Explain why some desert animals excrete uric acid rather than ammonia.
5. 1992 Q19 P1
Explain the part played by each of the following in homeostasis
(a) Insulin and Glucagon
(b) Antidiuretic hormone
6. 1993 Q2 P1
State the role of the following hormones in the body:
b. Antidiuretic hormone
7. 1993 Q10 P1
What osmoregulatory changes would take place in a marine amoeba if it was transferred to a fresh water environment?
8. 1994 Q2 P1
Name two components of blood that are not present in the glomerular filtrate.
9. 1994 Q3 P1
How would one find out from a sample of urine whether a person is suffering from diabetes mellitus?
10. 1995 Q17 P1
Describe how excretion takes place in
(i) Mammalian Kidneys
(ii) Green plants (5 marks)
11. 1996 Q3 P1
When is glycogen which is stored in the liver converted into glucose and released into the blood (1 mark)
12. 1996 Q21 P1
Explain how the mammalian skin is adapted to perform its functions (20 marks)
13. 1997 Q8 P1
A person was found to pass out large volumes of dilute urine frequently.
(a) Name the disease the person was suffering from
(b) Hormone that was deficient
14. 1997 Q15 P1
The equation below represent a metabolic that occurs in the mammalian liver
Amino acids →Organic compounds + urea
(a) Name the process.
(b) What is the importance of the process to the mammal?
(c) What is the source of amino acids in this process
(d) What is the difference between essential and nonessential amino acids?
15. 1999 Q11 P1
Give reasons for each of the following:
a) Constant body temperature is maintained in mammals.
b) Low blood sugar level is harmful to the body.
16. 2000 Q5 P1
State the importance of osmo-regulation in organisms
17. 2000 Q13 P1
The temperature of a person was taken before, during and after taking a cold bath. The results are shown in the graph below
(a) Explain why the temperature fell during bath
(b) What changes occurred in the skin that enabled the body temperature to return to normal?
18. 2001 Q6 P1
Adult elephants flap their ears twice as much as their calves in order to cool their bodies when it is hot. Explain.
19. 2001 Q11 P1
The diagram below represents a mammalian nephron
(a) Name the
(i) Structure labeled P
(ii) Portion of the nephron between point X and Y
(b) Name the process that takes place at point Q
(c) Name one substance present at point R but absent at point S in a healthy mammal
(d) The appearance of the substance you have mentioned in (c) above is a
symptom of a certain disease caused by a hormone deficiency. Name the
(e) State the structural modifications of nephrons found in the desert mammals
20. 2003 Q14 P1
a) Explain how marine fish regulate their osmotic pressure.
b) Explain the role of antidiuretic hormone when there is excess water in the human body.
21. Some students used a model to demonstrate the effect of sweating on human body temperature. Two boiling tubes A and B were filled with hot water. The temperature of water in the tubes was taken at the start of the experiment and then at 5 minutes interval.
The surface of tube A was continuously wiped with a piece of cotton wool soaked in methylated spirit. The results obtained are shown in the table below.
a) On the same axes, plot graphs of temperature of water in the tubes against time.
b) At what rate was the water – cooling in tube A?
c) Why was tube B included in the set up?
d) Account for the rate of cooling in tube A.
e) State two processes of heat loss in tube b.
f) What would be the expected results if tube A was insulated?
g) What would the insulation be comparable to in:
h) Name the structures in the human body that detect:
i) External temperature changes
ii) Internal temperature changes
22. 2004 Q18 P1
How is the mammalian skin adapted to its functions? (20 marks)
23. 2005 Q13 P1
The diagram below shows a section through the mammalian skin.
a) Name the parts labeled E, F and G. (3 marks)
b) State two functions in each case of substance secreted by the structures labelled.
(i) H (2 marks)
(ii) I (2 marks)
24. 2006 Q4 P1
a) Name the fluid that is produced by sebaceous glands. (1 mark)
b) What is the role of sweat in human skin? (2 marks)
25. 2006 Q7 P2
Describe how human kidney functions (20 marks)
26. 2007 Q14 P1
(a) What is the meaning of the terms
(i) Homeostatic (1 mark)
(ii) Osmoregulation? (1 mark)
(b) Name the hormones involved in regulating glucose level in blood (2 marks)
27. 2007 Q2 P2
(a) Explain what happens to excess amino- acids in the liver of humans (3 marks)
(b) Which portion of the human nephron are only found in the cortex? (3 marks)
(c)(i) What would happen if a person produced less antidiuretic hormone? (1 mark)
(ii) What term is given to the condition described in (c) (i) above (1 mark)
28. 2008 Q2 P1
State the importance of the following processes that take place in the nephrons of a human kidney
(a) Ultra filtration ( 1 mark)
(b) Selective reabsorption ( 1 mark)
29. 2008 Q11 P1
(a) What is homeostasis? (1 mark)
(b) Name three processes in the human body in which homeostasis is involved (3 marks)
30. 2009 Q17 P1
Explain why plants do not require specialized excretory organs (4 marks)
31. 2009 Q21 P1
Explain what happens in humans when concentration of glucose in the blood decreases below the normal level ( 4 marks)
32. 2009 Q8 P2
Describe the role of the liver in homeostasis in the human body (20 marks)
33. 2010 Q18 P1
Give two reasons why animals have specialized organ for excretion as compared to plants (2 marks)
34. 2010 Q19 P1
State the changes that occur in arterioles in the human skin during thermoregulation. (2 marks)
35. 2011 Q1 P1
Name two kidney diseases.(2 marks)
36.2011 Q25 P1
State one economic importance of each of the following plant excretory products.
37. 2011 Q7b P2
Explain how the human skin brings about cooling of the body on a hot day. (7 marks)
38. 2012 Q18, 19 P1
18. Why plants able to accumulate most of their waste products for long? (1 mark)
19. List four forms of diabetes mellitus. (4 marks)
39. 2012 Q2 P2
The diagram below illustrates the structure of the kidney nephron.
(a) Name the part labeled E. (1 mark)
(b) How the part is labeled F adapted to its function? (4 marks)
(c) State three physiological mechanisms of controlling the human body temperature during a cold day. (3 marks)
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kcse past papers
1. 1995 Q2 P1
Name the organelle that performs each of the following functions in a cell (2 marks)
a) Proteins synthesis____
b) Transport of cell secretions___
2. 1996 Q8 P1
State two functions of cell sap (2 marks)
3. 1997 Q1 P1
State the functions of the following cell organelles
a) Golgi apparatus
4. 1998 Q3 P1
Which organelle would be abundant in:
a) Skeletal muscle cell
b) Palisade cell
5. 2001 Q7 P1
Name the organelle in which protein synthesis takes place
6. 2004 Q7 P1
State the function of the organelles:
a) Lysosomes (1 marks)
b) Golgi apparatus (2 marks)
7. 2005 Q2 P1
The diagram below represents a cell.
a) Name the parts labelled X and Y (2 marks)
b) Suggest why the structures labelled X would be more on one side than the other. (1 mark)
8. 2006 Q1 P1
a) State the functions of cristae in mitochondria.
b) The diagram below represents a cell organelle.
i) Name the part labelled Y. (1 mark)
ii) State the functions of the part labelled X. (1 mark)
9. 2007 Q2 P1
a) What is the formula for calculating linear magnification of a specimen when using a hand lens?
b) Give a reason why staining is necessary when preparing specimens for observation under the microscope (1 mark)
10.2007 Q4 P1
State three functions of Golgi apparatus (3 marks)
11.2008 Q12 P1
State two functions of the endoplasmic reticulum (2 marks)
12.2009 Q3 P1
State the functions of the following parts of a light microscope (2 marks)
a) Objective lens _______
b) Diaphragm _______
13.2009 Q7 P1
State the function of the following cell organelles
a) Ribosome (1 mark)
b) Lysosomes (1 mark)
14.2009 Q15 P1
Name the type of movement that occurs within a plant cell (1 mark)
15.2009 Q26 P1
How are the mitochondria adapted to their functions? (2 marks)
16.2010 Q3 P1
State the function of:
a) Ribosomes (1 mark)
b) Lysosomes (1 mark)
17.2010 Q9 P1
State two ways in which chloroplasts are adapted to their functions. (2 marks)
18.2011 Q11 P1
State the functions of the following parts of a light microscope.
i) Fine adjustment knob.
ii) Stage (2 marks)
19.2011 Q15 P1
Give reasons for carrying out the following procedures when preparing temporary wet mounts of plant tissues.
a) Making thin plant sections (1 mark)
b) Adding water on the plant section. (1 mark)
c) Placing a cover slip over the plant section. (1 mark)
20.2012 Q3 P1
The figure below is a fine structure of a generalised animal cell as seen under an electron microscope.
a) Name the parts labelled A and B (2 marks)
b) How is the structure labelled B adapted to its functions (2 marks)
21.2012 Q12 P1
a) Name the part of a light microscope used to bring an image of a specimen into sharp focus. (1 mark)
b) Why is it recommended to keep the stage of the microscope dry? (1mark)
22.2012 Q27, 30 P1
27.What is the function of contractile vacuoles in amoeba? (1 mark)
30.Name the organelle that is involved in each of the following: (2 marks)
a) Manufacture of lipids
b) Formation of Lysosomes
TRANSPORTATION IN PLANTS AND ANIMALS
1. 1989 Q3 P1
Explain how the red blood cells of mammals are adapted for efficient transport of oxygen.
2. 1989 Q11 P1
In experiment, a leafy shoot was set-up in a perometer and kept in a dark room for two hours. The set up was then transferred to a well lit room for two hours.
(a) What is the aim of the experiment?
(b) Explain the result which would be expected in each of the two experimental conditions.
3. 1991 Q2 P1
Give two reasons why the pressure of blood is greater in the arteries that in the veins of mammals.
4. 1992 Q6 P1
Most carbon dioxide is transported from tissues to the lungs within the red blood cells and not in the blood plasma.
Give two advantages of this mode of transport.
5. 1992 Q17 P1
The amount of blood flow through various parts of a mammalian body was measured in cubic centimeters per minute at rest and also during physical activities.
The results are shown in the table below
(a) Calculate the percentage changes in the blood flow through the skeletal muscle and the gut when the mammal was subjected to strenuous exercise from rest.
(b) Account giving reasons for the differences in the amount of blood flow through the gut and skeletal muscles.
(c) How does the heart increase blood flow to some parts of the body during astrenuous exercise?
(d) Explain the results obtained for the skin
(e) Name three substances that are removed from the body by the Kidneys.
6. 1993 Q6 P1
State two functions of mammalian blood other than transport of substances
7. 1994 Q1 P1
Name a structure in veins which is not found in other blood vessels, that adapts them to their function.
8. 1995 Q11 P1
The diagram below represents a transverse section of a young stem
(a) Name the parts labelled A and B (2 marks)
b) State the functions of the parts labelled C, D and E (4 marks)
c) List three differences between the section shown above and one that would be obtained from the root of the same plant (3 marks)
9. 1996 Q17 P1
(a) How may excessive bleeding results in death? (4 marks)
(b) Name the process by which the human body naturally stops bleeding? (1 mark)
(c) How can low blood volume be brought back to normal (3 marks)
10. 1996 Q19 P1
The diagram below represents then pathways of water from the soil into the plant.
a) Name the structures labelled K and L. (2 marks)
b) Explain how water from the soil reaches the structure labelled L.(5 marks)
c) Name the process by which mineral salts enter into the plant (1 mark)
11. 1997 Q4 P1
State two ways in which xylem vessels are adapted to their function
12. 1997 Q13 P1
An experiment was carried out to determine the rate of transpiration in three plants A, B and C. Plants, A and B belonged to different species while plants B and C belonged to the same species. Plant C had all its leaves removed. The three plants were of similar size and were exposed to the same environment conditions.
The results are as shown below in the graphs below
(a) Suggest possible environment conditions under which the experiment was carried out between 30 and 60 minutes
(b) Account for the results obtained for plant C
(c) Suggest the habitat for plant A and B. Give reasons for your answer.
13. 1998 Q1 P1
Why are people with blood group O universal donors?
14. 1998 Q18 P1
A hungry person had a meal, after which the concentration of glucose and amino acids in the blood were determined. This was measured hourly as the blood passed through the hepatic portal vein and the iliac vein in the leg. The results were as shown in the table below.
(a) Using the same axes draw graphs of concentration of glucose in the hepatic portal vein and the iliac vein in the leg against time
(b) Account for the concentration of glucose in the hepatic vein from:
(i) 0/1 hour
(ii) 1-2 hour
(iii) 2- 4 hours
(iv) 5 – 7 hours
(c) Account for the difference in the concentration of glucose in hepatic portal vein and the iliac vein between 2 and 4 hours.
(d) Using the data provided in the table explain why the concentration of amino acids in the hepatic portal vein took longer to increase.
15. 1999 Q1 P1
Name two processes that bring about the translocation of manufactured food
16. 1999 Q2 P1
Give two reasons why accumulation of lactic acid during vigorous exercise leads to an increase in heartbeat.
17. 1999 Q14 P1
The photograph below represents a blood smear obtained from a person suffering from a certain disease.
//Diagram not availble now, check progress later
a) Name the structure labelled X.
b) i) Name the structure labelled L
ii) State the function of the source labelled M
c) What disease was the person suffering from?
d) List three ways by which micro-organisms enter the human body.
18. 2000 Q11ab P1
The diagram below represents a section of a leaf.
(a) Name the parts labelled X, and Y
(b) Using arrows indicate on the diagram the direction of flow of water during the transpiration stream
19. 2001 Q3 P1
A person whose blood groups is AB requires a blood transfusion. Name the blood groups of the donors.
20. 2001 Q8 P1
(a) The type of circulatory system found in members of the class insecta is
(b) Name the blood vessel that transports blood from:
(i) Small intestines to the liver
(ii) Lungs to the heart
21. 2002 Q6 P1
In what form is oxygen transported from the lungs to the tissues?
22. 2002 Q16 P1
The diagram below represents part of phloem tissue.
a) Name the structures labelled R and S and the cell labelled T.
b) State the function of the structure labelled S
c) Explain why xylem is a mechanical tissue
23. 2003 Q9 P1
a) Material that strengthens xylem tissue.
b) Tissue that is removed when the bark of a dicotyledonous plant is ringed.
24. 2004 Q2 P1
Distinguish between natural and acquired immunity (2 marks)
25. 2004 Q13 P1
The diagram below shows a vertical section through a mammalian heart.
a) Name the parts labelled A, B, E and F (4 marks)
b) Use arrows to show the direction in which blood flows in the heart. (2 marks)
c) Give a reason why the wall of chamber C is thicker than chamber D (2 marks)
26. 2005 Q3 P1
What is the role of the vascular bundles in plant nutrition? (3 marks)
27. 2005 Q9 P1
Why would carboxyhaemoglobin lead to death? (2 marks)
28. 2005 Q14 P1
A set up that was used to investigate certain process in plants is shown in the diagram below.
a) What process was being investigated? (1 mark)
b) (i) State two precautions that should be taken when setting up the experiment. (2 marks)
(ii) Give a reason for each precaution stated in b(i) above. (2 marks)
c) State three environmental factors that influence the process under investigation. (3 marks)
29. 2006 Q7 P1
a) Name one defect of circulatory system in humans. (1 mark)
b) State three functions of blood other than transport. (3 marks)
30. 2006 Q4 P2
The diagram below represents a traverse section through a plant organ
a). From which plant organ was the section obtained? (1 mark)
b). Give two reasons for your answer in (a) above. (2 marks)
c). Name the parts labelled J, K and L. (3 marks)
d). State two functions of the part labelled M. (2 marks)
31. 2006 Q8 P2
Describe how water moves from the soil to the leaves in a tree. (20marks)
32. 2007 Q9 P1
State two ways in which the root hairs are adapted to their function (2 marks)
33. 2007 Q10 P1
The diagram below represents a plant tissue
(a) Name the tissue (1 mark)
(b) Name the cells labelled K and L. (2 marks)
(c) What is the function of the companion cell? (1 mark)
34. 2007 Q11 P1
(a) What prevents blood in veins from flowing backwards? (1 mark)
(b) State two ways in which the blood cells are adapted to their function (2 marks)
35. 2007 Q6 P2
In the experiment to determine the effect of ringing on the concentration of sugar in phloem a ring of bark from the stem of a tree was cut and removed. The amount of sugar in grammes per 16cm3 piece of bark above the ring was measured over a 24 hour period. Sugar was also measured in the bark of a similar stem of a tree which was not ringed. The results are shown in the table below.
(a) Using the same axes, plot a graph of the amount of sugar against time (6 marks)
(b) At what time was the amount of sugar highest in the
(i) Ringed stem (1 mark)
(ii) Normal stem? (1 mark)
(c) How much sugar would be in the ringed stem if it was measured at 0345 hours? (1 mark)
(d) Give reasons why there was sugar in the stems of both trees at 06 45 hours (2 marks)
(e) Account for the shape of the graph for the tree with ringed stem between:
(i) 06 45 hours and 15 45 hours (3 marks)
(ii) 15 45 hours and 00 45 hours (2 marks)
(f) Name the structures in phloem that are involved in the translocation of sugars (2 marks)
(g) Other than sugars name two compounds that are translocated in phloem (2 marks)
36. 2008 Q20 P1
(a) What is a single circulatory system (1 mark)
(b) Name an organism which has single circulatory system (1 mark)
(c) Name the opening to the chamber of the heart of an insect (1 mark)
37. 2008 Q6 P2
An experiment was carried out to investigate transpiration and absorption of water in sunflower plants in their natural environment with adequate supply of water.
The account of water was determined in two hour intervals. The results are as shown in the table below
(a) Using the same axes, plot graphs to show transpiration and absorption of water in grammes against time of the day (7 marks)
(b) At what time of the day was the amount of water the same for transpiration and absorption? (1 mark)
(c) Account for the shape of graph of:
(i) Transpiration ( 3 marks)
(ii) Absorption ( 3 marks)
(d) What would happen to transpiration and absorption of water if the experiment was continued till 05 00 hours? (2 marks)
(e) Name two factors that may affect transpiration and absorption at any given time (2 marks)
(f) Explain how the factors you named in (e) above affect transpiration (2 marks)
38. 2009 Q6 P1
The diagram below shows a section through a plant organ
(a) (i) Name the class of the plant which the section was obtained ( 1 mark)
(ii) Give a reason for your answer in (a) (i) above
(b) State the functions of the part labelled F (1 mark)
39. 2009 Q28 P1
(a) State three structural differences between arteries and veins in mammals (3marks)
(b) Name a disease that causes thickening and hardening of arteries (1 mark)
40. 2009 Q29 P1
Explain why the rate of transpiration is reduced when humidity is high
41. 2010 Q14 P1
Explain why is not advisable to be in a poorly ventilated room with a burning charcoal. (3 marks)
42. 2010 Q23 P1
Explain three ways in which red blood cells are adapted to their function. (3 marks)
43. 2010 Q 28 P1
State three structural differences between arteries and veins. (3 marks)
44. 2010 Q2 P2
The diagram below shows blood circulation in a mammalian tissue.
a) Name the part labelled P and Q (2 marks)
b) Name the substance that are:
i) Required for respiration that move out of capillaries; (2 marks)
ii) Remove from tissue cells as a result of respiration (2 marks)
c) Explain how substances move from blood capillaries into the tissue cells. (2 marks)
d) Name one component of the blood that is not found in the part labelled P (1mark)
45. 2011 Q16 P1
a) Describe the condition known as varicose veins. (2 marks)
b) What is the role of blood platelets in the blood clotting process? (2 marks)
46. 2011 Q20 P1
The number of stomata on the lower and upper surfaces of two leaves from plant species X and Y were counted under the field of view of a light microscope. The results were as shown in the table below.
a) Which of the two leaves would be expected to have a lower rate of transpiration? (1 mark)
b) Give a reason for your answer in (a) above. (1 mark)
47. 2011 Q7a P2
a) Explain how the structural features in terrestrial plants affect their rate of transpiration. (13 marks)
48. 2012 Q8 P2
What is the probability of a couple with blood group AB getting a child with blood group AB? Show your working. (4 marks)
49. 2012 Q11 (a) P1
(a) State two ways in which heart muscles are special. (2 marks)
50. 2012 Q23, 28 P1
23. Name the strengthening materials found in the following support tissues:
(b) Xylem (2 marks)
28. State two differences between open and closed circulatory systems (2 marks)
51 2012 Q8 P2
(a) Using a relevant example, describe how an allergic reaction occurs in a human being. (10 marks)
(b) Describe how environmental factors increase the rate of transpiration in terrestrial plants. (10 marks)
1. 1992 Q7 P1
Active yeast cells were added to a dilute sugar solution in a container. The mixture was kept in a warm room. After a few hours bubbles of gas were observed escaping from the mixture.
(a) Write an equation to represent the chemical reaction above.
(b) What is the economic importance of this type of chemical reaction in industry?
2. 1993 Q9 P1
Give the formula for calculating the respiratory quotient (R.Q).
3. 1994 Q4 P1
Explain why a baby uses more heat per unit weight than an adult when to the same environmental conditions?
4. 1996 Q14 P1
(a) Describe the path taken by carbon dioxide released from the tissue of an insect to the atmosphere (3 marks)
(b) Name two structures used for gaseous exchange implants (2 marks)
5. 1997 Q3 P1
What are the three end products of anaerobic respiration in plants
6. 2000 Q15 P1
The concentration of the lactic acid in blood during and after an exercise was determined. The results are shown in the graph below
(a) (i) By how much did the lactic acid increase at the end of 13 minutes?
(ii) After how many minutes was the lactic acid concentration 71mg/ 100cm3?
(iii) What would be the concentration of lactic acid at the 60th minute?
(b) Give a reason for the high rate of production of lactic acid during the exercise
(c) Give a reason for the decrease in the concentration of lactic acid after the exercise
7. 2002 Q18 P1
Two person X and Y drunk volumes of concentrated solution of glucose. The amount of glucose in their food was determined at intervals. The results are shown in the table below:
a) On the grid provided, plot graphs of glucose level in blood against time on the same axes.
b) What was the concentration of glucose in the blood of X and Y at the 20th minute?
c) Suggest why the glucose level in person X stopped rising after 30 minutes while it continued rising in person Y.
d) Account for the decrease in glucose level in person X after 30 minutes and person Y after 60 minutes (3 marks)
e) Name the compound that stores energy released during oxidation of glucose.
f) Explain what happens to excess amino acids and development of plants.
8. 2003 Q1 P1
A process that occurs in plants is represented by the equation below.
a) Name the process.
b) State the economic importance of the process named in (a) above
9. 2004 Q4 P1
Other than carbon dioxide, name other products of anaerobic respiration (2 marks)
10. 2005 Q6 P1
Name the substance which accumulates in muscles when respiration occurs with insufficient oxygen. (1 mark)
11. 2006 Q13 P1
a) In what form is energy stored in muscles (1 mark)
b) State the economic important of anaerobic respiration in plants. (2 marks)
12. 2006 Q24 P1
State four ways in which respiratory surfaces are suited to their function. (4 marks)
13. 2006 Q25 P1
A dog weighing 15.2kg requires 216kj while a mouse weighing 50g requires 2736kj per day. Explain. (2 marks)
14. 2007 Q13 P1
(a)Name the products of anaerobic respiration in
(i) Plants (1 mark)
(ii) Animals (1 mark)
(b)What is oxygen debt? (1 mark)
15. 2008 Q3 P2
The equation below represents a process that takes place in plants
(a) Name the process (1 mark)
(b) State two conditions necessary for the process to take place (2 marks)
(c) State what happens to the end- products of the process (5 marks)
16. 2009 Q27 P1
State two ways in which anaerobic respiration is applied in industries (2 marks)
17. 2010 Q5 P1
State three ways in which a respiratory surface is adapted to its function. (3 marks)
18. 2011 Q10 P1
a) Give two differences in the products of anaerobic respiration between plants and animals. (2 marks)
b) Name the site of anaerobic respiration in a cell. (1 mark)
19. 2011 Q19b P1
Write an equation that summarizes the process of aerobic respiration (1 mark)
20. 2012 Q7 P1
The diagram below represents a set-up that students used in an investigation.
(a) Name the physiological process that was being investigated. (1mark)
(b) State the role of potassium hydroxide in flask K. (1mark)
(c) Account for the observation in boiling tube L and flask N. (2 marks)
21. 2012 Q14 P1
(a) Name the type of respiration that is most efficient. (1 mark)
(b) Giving a reason for your answer in (a) above (1 mark)
1. 1992 Q11 P1
The diagram below represents an organ from a bony fish. Study the diagram and answer the questions that follow
(a) Identify the organ and the parts labelled M, N, and P
(b) How the structures are labelled P adapted to their function?
2. 1994 Q14 P1
What are the characteristics do gills of a fish and the mouth cavity of a frog have in common that enables them to be efficient in gaseous exchange?
3. 1996 Q14 P1
(a) Describe the path taken by carbon dioxide released from the tissue of an insect to the atmosphere (3 marks)
(b) Name two structures used for gaseous exchange in plants (2 marks)
4. 1998 Q4 P1
Why are gills in fish highly vascularised?
5. 1999 Q5 P1
Suggest three reasons why green plants are included in a fish aquarium.
6. 1999 Q16 P1
a) Process of inhalation in mammals.
b) Mechanisms of opening and closing of stomata in plants.
7. 2000 Q11c P1
State two ways in which the leaf is suited to gaseous exchange
8. 2001 Q10 P1
Name three sites where gaseous exchange takes place in terrestrial plants.
9. 2002 Q9 P1
Name two gaseous exchange structures in higher plants.
10. 2003 Q13 P1
The diagram below shows gaseous exchange in tissues.
a) Name the gas that diffuses:
i) To the body cells
ii) From the body cells
b) Which compound dissociates to release the gas named in (a) (i) above?
c) i) What is tissue fluid?
ii) What is the importance of tissue fluid?
d) Name the blood vessel with the highest concentration of:
ii) Carbon dioxide
11. 2004 Q3 P1
The diagram below represents a part of the rib cage.
a) Name the parts labelled W, Y and Z. (3 marks)
b) How does the part labelled Z facilitates breathing in? (3 marks)
12. 2005 Q18 P1
Describe how gaseous exchange takes place in terrestrial plants. (20 marks)
13. 2006 Q5 P1
State two ways in which floating leaves of aquatic plants are adapted to gaseous exchange. (2 marks)
14. 2007 Q12 P1
(a)Name two structures for gaseous exchange in aquatic plant (2 marks)
(b)What is the effect of contraction of the diaphragm muscles during breathing in mammals? (3 marks)
15. 2007 Q1 P2
The diagram below represents some gaseous exchange structures in humans
(a) Name the structures labeled K, L, and M (3 marks)
(b) How is the structure labeled J suited to its function? (3 marks)
(c) Name the process by which inhaled air moves from the structure labeled L into blood capillaries ( 1 mark)
(d) Give the scientific name of the organism that causes tuberculosis in humans (1 mark)
16. 2008 Q8 P2
(a)State four characteristics of gaseous exchange surfaces (4 marks)
(b) Describe the mechanism of gaseous exchange in a mammal (16 marks)
17. 2009 Q16 P1
(a) Name the gaseous exchange surface in insects (1 mark)
(b) How is the surface named in (a) above suited to its function (2 marks)
18. 2011 Q19a P1
a) Apart from the lungs, name two gaseous exchange surfaces in a frog. (2 marks)
19. 2011 Q22 P1
State the difference in content of oxygen and carbon (IV) Oxide in the air that enters and leaves the human lungs. (2 marks)
20. 2011 Q3a, b P2
a) Name the causative agents for the following respiratory diseases.
i) Whooping cough. (2 marks)
ii) Pneumonia (2 marks)
b) Describe how oxygen in the alveolus reaches the red blood cells (4 marks)
21. 2012 Q6 P1
The diagram below represents part of gaseous exchange system in human
(a) Name the parts labelled F and G. (2 marks)
(b) State one function of each of the parts labelled H and J (2 marks)
22. 2012 Q5 P2
(a) Describe the process of inhalation. (4 marks)
(b) Explain the mechanism of stomatal opening (4 marks)
INTRODUCTION TO BIOLOGY
1. 1995 Q 1 P1
Motor vehicles move, use energy and produce carbon dioxide and water. Similar characteristics occur in living organisms yet motor vehicles are not classified as living. List the other characteristics of living things that do NOT occur in motor vehicles.
2. 2010 Q 1 P1
Give the name to the study of:
a) The cell (1 mark)
b) Micro--organism. (1 mark)
NUTRITION IN PLANTS AND ANIMALS
1. 1989 Q1 P1
The diagram below shows chemical reactions I, and II which are controlled by enzymes respectively.
Name reaction II and enzyme B
2. 1990 Q1 P1
Explain the biological principles behind the preservation of meat be:-
3. 1991 Q4 P1
State one similarity and one difference between parasitic and predatory modes of feeding
4. 1991 Q9 P1
In an investigation, the pancreatic duct of a mammal was blocked. It was found that the blood sugar regulation remained normal while food digestion was impaired. Explain these observations.
5. 1992 Q1 P1
(a) Name the products of light reaction in photosynthesis.
(b) Explain why insectivorous plants such as Drosera species trap and digest insects
6. 1992 Q12 P1
a) (i) Identify the mode of feeding of the animal whose dental formula is given below
I 0 C0 pm 3 m2
2 0 3 2
(ii) Give reasons for your answer in (a) (i) above
(b) Give four ways by which the tapeworm is (taenia Spp) is adapted to living in the alimentary canal of its host.
7. 1993 Q1 P1
Explain how a greyish black substance develops on a moist slice of bread after a few days.
8. 1993 Q5 P1
Give a reason why lack of roughage in diet often leads to constipation
9. 1993 Q18 P1
(a) Name the various methods used in preserving food.
(b) Explain how each of the methods you have named in (a) above works.
10. 1994 Q20 P1
Describe the economic importance of:
11. 1995 Q5 P1
State the role of light photosynthesis (2 marks)
12. 1995 Q7 P1
Complete the table below on mineral nutrition in plants (3 marks)
13. 1996 Q4 P1
Name the disease in humans that is caused by lack of vitamin C (1 mark)
14. 1996 Q7 P1
(a) State the role of light in the process of photosynthesis (1 mark)
(b) Name one end product of dark reaction in photosynthesis (1 mark)
15. 1997 Q10 P1
Name a disease caused by lack of each of the following in human diet.
16. 1997 Q20 P1
(a) What is meant by the term digestion?
(b) Describe how the mammalian small intestine is adapted to its function
17. 1998 Q2 P1
State one effect of magnesium deficiency in green plants
18. 1998 Q14 P1
In an experiment to investigate a factor affecting photosynthesis, a leaf of a potted plant which had been kept in the dark overnight was covered with aluminum foil as shown in the diagram below
The set up was kept in sunlight for three hours after which a food test was carried out on the leaf.
(a) Which factor was being investigated in the experiment?
(b) What food test was carried out?
(c) (i) State the results of the food test
(ii) Account for the results in c (i) above
(d) Why was it necessary to keep the plant in darkness; before the experiment?
19. 1998 Q20 P1
Explain how the mammalian intestines are adapted to perform their function.
20. 2001 Q5 P1
State two functions of muscles found in the alimentary canal of mammals.
21. 2001 Q12 P1
The graph below shows the effect of substance concentration of the rate of enzyme reaction.
(a) (i) Account for the shape of the graph between A and B
(ii) B and C
(b) How can the rate of reaction be increased after point B?
(c) State two other factors that effect the rate of reaction of enzyme reaction
22. 2001 Q16 P1
An experiment was carried out to investigate the nutritional value of two dry powder animals feeds X and Y over a period of six months. Twenty 5 month’s old castrated goats were use. The goats were divided into two equal groups A and B. The animal’s in group A were fed on feed X throughout the experiment while those of group B were fed on feed Y. The feeds were supplemented with dry hay and water. The average body weight of each group of goats and the weight of the dry powder feeds were determined and recorded each month. The faeces produced by each group was dried and weighed and the average dry faecal output per month was also recorded. The results are as shown below.
(a) (i) What is the relationship between the amount of feed and the faecal output
(ii) Work out the average increase in weight for the animal’s in group A during
The first four months
The last two months
(iii) Account for the average increase weight in goats in group A during the first four months
The last two months
(iv) Which of the two feeds is more nutritious?
Give reason for your answer
(b) State four uses of digested food in the bodies of animals
(c) State four uses of water in the bodies of animals
23. 2002 Q3 P1
a) State the function for co-factors in cell metabolism
b) Give one example of a metallic co – factor
24. 2002 Q10 P1
What happens to excess fatty acids and glycerol in the body?
25. 2003 Q8 P1
State a function of the large intestine in humans
26. 2004 Q9 P1
Name two mineral elements that are necessary in the synthesis of chlorophyll. (2 marks)
27. 2006 Q8 P1
State the role of vitamin C in humans. (2 marks)
28. 2006 Q11 P1
State the role of insulin in human body. (1 mark)
29. 2006 Q17 P1
a) Distinguish between the terms homodont and heterodont. (1 mark)
b) What is the function of carnassials teeth? (1 mark)
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 six molars. Write its dental formula.
30. 2006 Q18 P1
a) State two functions of bile juice in the digestion of food. (2 marks)
b) How does substrate concentration affect the rate of enzyme action? (1 mark)
31. 2006 Q27 P1
Name the end products of the light stage in photosynthesis.
32. 2007 Q6 P1
Describe what happens during the light stage of photosynthesis (3 marks)
33. 2007 Q7 P1
The diagram below represents a section though a human tooth
(a) (i) Name the type of tooth shown (1 mark)
(ii) Give a reason for your answer in (a) (i) above (1 mark)
(b) State the functions of the structures found in part labelled J (2 marks)
34. 2007 Q8 P1
(a) Name a fat soluble vitamin manufactured by the human body (1 mark)
(b) State two functions of potassium in the human body (2 marks)
35. 2007 Q25 P1
(a) The action of ptyalin stops at the stomach. Explain (1 mark)
(b) State a factor that denatures enzymes (1 mark)
(c) Name the features that increase the surface area of small intestines (2 marks)
36. 2008 Q5 P1
(a) State two factors that affect enzymatic activities (2 marks)
(b) Explain how one of the factors stated in (a) above affects enzymatic activities
37. 2008 Q9 P1
Give three factors that determine the amount of energy a human being require in a day (3 marks)
38. 2008 Q10 P1
(a) Name the antigens that determine human blood groups (2 marks)
(b)State the adaptation that enables the red blood cells to move in blood capillaries (1 mark)
39. 2008 Q15 P1
Explain what happens when there is oxygen debt in human muscles (2 marks)
40. 2008 Q16 P1
The diagram below represents a set up that was used to investigate certain process in a plant
(a) State the process that was being investigated (1 mark)
(b) State a factor that would affect the process (1 mark)
41. 2008 Q18 P1
How is the epidermis of a leaf of a green plant adapted to its function (2 marks)
42. 2008 Q23 P1
The diagram below shows a human tooth (2 marks)
(a) Identify the tooth (1 mark)
(b) How is the tooth adapted to its function (1 mark)
(c) State the role of the following vitamins in the human body
(i) C (1 mark)
(ii) K (1 mark)
43. 2008 Q24 P1
Name the sites where light and dark reactions of photosynthesis take place (2 marks)
44. 2009 Q18 P1
Explain how the following factors affect the rate of photosynthesis:
(a) Concentration of carbon (iv) oxide (1 mark)
(b) Light intensity (1 mark)
45. 2009 Q22 P1
Explain how the carnassials teeth of a dog are adapted to their function (2 marks)
46. 2009 Q23 P1
State the function of iron in the human body (1 mark)
47. 2009 Q24 P1
Explain how the following factors determine the daily energy requirement in human:
(a) Age ( 1 mark)
(b) Occupation (1 mark)
(c) Sex (1 mark)
48. 2009 Q2 P2
The diagram below represents the lower jaw of a mammal
(a) Name the mode of nutrition of the mammal whose jaw is shown (1 mark)
(b) State one structural and one functional difference between the teeth labelled J and L
Structural (1 mark)
Functional (1 mark)
(c) (i) name the toothless gap labeled K. (1 mark)
(d) Name the substance that is responsible for hardening of teeth (1 mark)
49. 2010 Q16 P1
What is the role of bile salts in humans? (2 marks)
50. 2010 Q17 P1
The following is the dental formula of a certain mammal:
i 0/3 c 0/1 pm 3/3 m3/3
a) State the likely mode of feeding for the mammal. (1 mark)
b) Give a reason for your answer in (a) above. (1 mark)
51. 2011 Q2 P1
a) Write the dental formula of an adult human. (1 mark)
b) Name two dental diseases. (2 marks)
52. 2011 Q13 P1
State two functions of carbohydrates in the human body (2 marks)
53. 2011 Q18 P1
a) Name one salivary gland in humans. (2 marks)
b) State two functions of saliva. (2 marks)
54. 2012 Q1 P1
How does nutrition as a characteristic of living organisms differ in plants and animals? (2 marks)
55. 2012 Q11 (b) P2
Name the muscles found in the following organs:
Bone……………………………………………………… (2 marks)
56. 2012 Q29 P1
Name two nutrients that are observed without being digested by enzymes in humans. (2 marks)
57. 2012 Q3 P2
(a) In an investigation, equal amounts of water was placed in three test tubes labeled G,H and J. Pond weeds of equal length were dropped in each test tube. The test tubes were then placed in Identical conditions of light and carbon(IV)oxide at different temperatures for five minutes. After five minutes, the bubbles produced in each test tube were counted for one minute. The results were as shown in the table below.
(i) Name one requirement for this process that is not mentioned in the investigation. (1 mark)
(ii) Name the gas produced in this investigation. (1 mark)
(iii) Account for the results in test tubes H and J. (2 marks)
(b) State two ways in which the human intestinal villus is adapted to its function.(4 marks)
1. 1995 Q3 P1
State two ways in which some fungi are harmful to man (2 marks)
2. 1995 Q6 P1
The diagram below represents a fern
(a) The parts labelled A and B ( 2 marks)
(b) The division to which the plant belongs ( 1 mark)
3. 1996 Q5 P1
An organ is with an exoskeleton, segmented body, two pairs of legs per segment, a pair of eyes and a pair short antennae belongs to the phylum (1 mark)
4. 1996 Q6 P1
What are two organisms considered to belong to the same species (2 marks)
5. 1997 Q2 P1
A student caught an animal which had the following characteristics:
The animal belongs to the class?
6. 1998 Q16 P1
A student placed a drop of pond water in a cavity slide and observed it under the microscope. The student observed many fast moving organisms, one of which is represented in the diagram below.
(a) (i) Name the phylum to which the organism belongs
(ii) Give a reason for your answer in (a) (i) above
(b) Name the structures labelled N, P and Q.
(c) State two observable features that enable the organism to move fast.
7. 1999 Q10 P1
Below is a list of organisms, which belong to classes Insecta, Myriapoda and Arachnida: Tick, centipede, praying mantis, tsetse fly, millipede and spider. Place the organisms in their respective classes in the table below.
Give reason in each case.
8. 2000 Q3 P1
State two characteristic features of members of phylum Bryophyta.
9. 2000 Q4 P1
State two ways in which some fungi are beneficial to humans.
10. 2001 Q1 P1
Other than having many features in common, state the other characteristics of a Species
11. 2002 Q1 P1
Beside the abdomen, name the other body part of members of Arachnida.
12. 2003 Q2 P1
Name the phylum whose members possess notochord
13. 2004 Q8 P1
Name the class in the phylum Arthropoda which has the largest number of individuals? (1 mark)
14. 2005 Q5 P1
To which class does an animal with two body parts and four pairs of legs belong? (1 mark)
15. 2006 Q6 P1
a) State three characteristics of Monera that are not found in other kingdoms.
b) Name the class to which a termite belongs (1 mark)
16. 2007 Q1 P1
(a) What is meant by the term binomial nomenclature (1 mark)
(b) Give two reasons why classification is important (2 marks)
17. 2008 Q25 P1
Giving a reason in each case, name the class to which each of the following organisms belong (4 marks)
18. 2009 Q1 P1
(a) Name the external feature which is common in birds, fish and reptiles (1 mark)
(b) State two characteristics of fungi (2 marks)
19. 2010 Q8 P1
State three external differences between chilopoda and diplopoda. (3 marks)
20. 2011 Q3 P1
Give three reasons for classifying organisms. (2 marks)
21. 2011 Q4 P1
State one use for each of the following apparatus in the study of living organisms.
a) Pooter (1 mark)
b) Pitfall traps. (1 mark)
22. 2011 Q8 P1
State three characteristics of the class crustacea. (3 marks)
23. 2012 Q2 P1
The diagram below represents a certain organism collected by a student at the sea shore
(a) Name the class to which the organism belongs (1mark)
(b) Give three reasons for your answer in (a) above (3 marks)
1. 1989 Q14 P1The table below shows the concentration of some ions in pond water and in the cell sap of an aquatic plant growing in the pond.
(i) Sodium ions
(ii) Potassium ions
(b) For each processes named in (a) (i) and (ii) above, state one condition necessary for the process to take place.
2. 1990 Q4 P1The diagram below represents a section through a chloroplast as seen under the electron microscope.
a) Name the structure labeled D
b) In which labeled structure would you expect to find chlorophyll molecules?
c) In which of the labeled structures does carbon dioxide fixation occurs?
3. 1991 Q14 P1A group of students set up an experiment to demonstrate a certain process.
The experiment was set up as shown in the diagram below.
After 10 minutes the students recorded their observation in a table as shown below.
(b) Explain the result in experiment set up
(c) What results would be expected if the experiment was repeated using starch solution which had been boiled with dilute hydrochloric acid for 5 minutes?
4. 1993 Q12 P1An experiment was carried out to investigate the effect of different concentrations of sodium chloride on human red blood cells. Equal amounts of blood were added to equal volumes of the salt solution but of different concentrations. The results are shown in the table below.
Number of red blood cells
(b) If the experiment was repeated using 1.4% sodium chloride solution state the expected results with reference to
(i)The number of red blood cells
(ii)The appearance of red blood cell if viewed under the microscope
5. 1994 Q6 P1Give a reason for each of the following
a) A mature plant cell does not lose its shape even after losing water.
b) Xylem vessels do not collapse even when they do not contain water.
6. 1994 Q12 P1Below is a diagram of an organism
(a) (i) Name the phylum to which the organism belong
(ii) Give reasons for your answer in a (i) above
(b) Outline the process by which the food particles got into the organism.
(c) Describe what happens to the food particles eventually.
7. 1995 Q4 P1Explain what would happen to red blood cells if they are placed in a concentrated salt solution ( 2 marks)
8. 1995 Q10 P1An experiment was carried out to investigate the rate of reaction shown below
Sucrose âFructose + Glucose
For the products fructose and glucose to be formed, it was found that substance K was to be added and the temperature maintained at 370C. When another substance L was added, the reaction slowed down and eventually stopped.
(a) Suggest the identify of substances K and L (2 marks)
(b) Other than temperature state three ways by which the rate of reaction could be increased (3 marks)
(c) Explain how substance L slowed down the reaction (2 marks)
9. 1999 Q15 P1An experiment was carried out to investigate haemolysis of human red blood cells.
The red blood cells were placed in different concentrations of sodium chloride solution. The percentage of haemolysed cells was determined. The results were as shown in the table below.
ii) At what concentration of salt solution was the proportion of haemolysed cells equal to non-haemolysed cells?
iii) State the percentage of cells haemolysed at salt concentration of 0.45%
b) Account for the results obtained at:
i) 0.33 percent salt concentration.
ii) 0.48 percent salt concentration.
c) What would happen to the red blood cells if they were placed in 0.50 percent salt solution?
d) Explain what would happen to onion epidermal cells if they were placed in distilled water.
10. 2000 Q8 P1Why is oxygen important in the process of active transport in cells?
11. 2004 Q16 P1a) What is diffusion (2 marks)
b) How do the following factors affect the rate of diffusion?
i) Diffusion gradient (1 mark)
ii) Surface area volume ratio (1mark)
iii) Temperature (1mark)
c) Outline three roles of active transport in the human body (3 marks)
12. 2005 Q7 P1State the importance of osmosis in plants. (3 marks)
13. 2006 Q12 P1An experiment was set up in the experiment as show below.
The set up was left for 30 minutes.
a) State the expected results. (1 mark)
b) Explain your answer in (a) above (3 marks)
14. 2007 Q3 P1Plant cells do not burst when immersed in distilled water. Explain (2 marks)
15. 2007 Q5 P1Distinguish between diffusion and osmosis (2 marks)
16. 2008 Q4 P1The diagrams below show a red blood cell that was subjected to a certain treatment
(a)Account for shape of the cell at the end of the experiment (2 marks)
(b)Draw a diagram to illustrate how a plant cell would appear if subjected to the same treatment (1 mark)
17. 2008 Q5 P2A freshly obtained dandelion stem measuring 5 cm long was split lengthwise to obtain two similar pieces. The pieces were placed in solutions of different concentrations in Petri dishes for 20 minutes. The appearance after 20 minutes is as shown
(a) Account for the appearance of the pieces in solutions L1 and L2 (6 marks)
(b) State the significance of the biological process involved in the experiment (2 marks)
18. 2009 Q13 P1(a) Distinguish between diffusion and active transport (2 marks)
(b) State one role that is played by osmosis in (1 mark)
19. 2010 Q7 P1Distinguish between haemolysis and plasmolysis. (2 marks)
20. 2010 Q6 P2
In an experiment to investigate a certain physiological process, a boiling tube labeled A and a test tube labeled B were covered with cotton wool. The two tubes were simultaneously filled with hot water and fitted with thermometers. The experimental set-up was as in the diagrams below.
The temperatures reading were taken at the start and after every two minutes for twenty minutes. The results were as shown in the table below.
a) Using the same axes, draw graphs of temperature against time. (6 marks)
b) i) Work out the rate of heat in the boiling tube labeled A and test tube labeled B
i) between the 5th and 15th minutes.
ii) Account for the answers in (b) (i) above. (2 marks)
iii) How does the explanation in (b) (ii) above apply to an elephant and a rat? (2 marks)
c) i) State the role of the cotton wool in this experiment.(1 mark) ii) Name two structures in mammals that play the role stated in (c) (i) above (2 marks)
d) State three advantage of having constant body temperature in mammals. (3 marks)
21. 2011 Q6 P2(a) An experiment was carried out to investigate the population of a certain micro-organism. Two Petri-dishes were used. Into the Petri â dish labeled M, 60cm3 of a culture medium was placed while 30cm3 of the same culture medium was placed in Petri-dish labeled N. Equal numbers of the micro-organisms were introduced in both Petri-dishes. The set-ups were then incubated at 350C. The number of micro-organisms in each Petri-dish was determined at irregular intervals for a period of 60hours. The results were as shown in the table below.
ii) After how many hours was the difference between the two populations greatest? (1mark)
iii) Work out the difference between the two populations at 50 hours. (2marks)
iv) With a reason state the effect on the population of micro-organisms in Petri â dish M if the temperature was raised at 600C after 20 hours. (2marks)
v) Account for the shape of the curve for population in petri-dish N between 46 hours and 59 hours
(b) Explain how the osmotic pressure in the human blood is maintained at normal level (5 marks)
22. 2012 Q4 P1In an investigation, a student extracted three pieces of pawpaw cylinders using a cork borer. The cylinders were cut back to 50mm length and placed in a beaker containing a solution. The results after 40mins were as shown in the table below.
(b) What would be a suitable control set-up for the investigation? (2 marks)
23. 2012 Q13 P1State three factors that affect the rate of diffusion (3 marks)