KCSE TOPICAL QUESTIONS & ANSWERS
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)
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