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BIOLOGY PAPER 231/1 K.C.S.E 1997
QUESTIONS
Answer all the questions in this section in the spaces provided
- State the functions of the following cell organelles
- Golgi apparatus
- Ribosomes
- A student caught an animal which had the following characteristics:
Body divide into two parts
Simple eyes
Eight legs
The animal belong to the class
- What are the three end products of anaerobic respiration in plants
- state two ways in which xylem vessels are adapted to their function
- In an accident a victim suffered brain injury. Consequently he had loss of memory. Which part of the brain was damaged?
- Oil can be applied on the stagnant water to control the spread of malaria.
- How does this practice control the spread of malaria?
- Give a reason why this practice should be discouraged
- State three structural differences between biceps muscles of the gut.
Biceps | Gut Muscles |
Striated | Unstriated |
Multinucleated | Uninucleated |
Long fibres | Short fibres |
Cylindrical | Spindle shaped |
- A person was found to pass out large volumes of dilute urine frequently.
Name the
- Disease the person was suffering from
- Hormone that was deficient
- state three pieces of evidence that support the theory of evolution
- Name a disease caused by lack of each of the following in human diet.
Vitamin D
Iodine
SECTION B (40 MARKS)
- The following below represents a feeding relationship in an ecosystem
- Write down the food chains in which the guinea fowls are secondary consumers
- What would be the short term effects on the ecosystem if lions invaded the area?
- Name the organism through which energy from the sun enters the
food web.
- A person was able to read a book clearly at arm’s length but at normal reading distance.
- State the detect the person suffered from?
- Why was he unable to read book clearly at normal distance
- How can the defect be corrected?
- 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
- Suggest possible environment conditions under which the experiment was carried out between 30 and 60 minutes
- Account for the results obtained for plant C
- Suggest the habitat for plant A and B. Give reasons for your answer.
Habitat for plant A
Habitat for plant B
- The diagram below represents a simplified nitrogen cycle.
- Name the organisms that cause process E and J
- Name the process represented by F and H.
- Name the group of organism represented by G
- The equation below represent a metabolic that occurs in the mammalian live
Amino acids →Organic compounds + urea
- Name the process.
- What is the importance of the process to the mammal?
- What is the source of amino acids in this process
- What is the difference between essential and nonessential amino acids?
- In a breeding experiment, plants with red flowers were crossed. The produced 123 plants with red flowers and 41 with white flowers
(a) Identify the recessive character
Give a reason
(b) What was the genotype of the parent plants that gave rise to the plants with a red and white flowers?
- Which letters in figures 1 and 2 represents the organs that produce female gametes?
Figure 1
Figure 2
- What is the function of the structure labeled S?
- Name the structure labeled W
- Which letters in figures 1 and 2 represents the structures where fertilization takes place
- Which letter in figure 1 represents the structure where male gametes are produced?
SECTION C (40 marks)
- An experiment was carried out to determine the growth rates of bamboo and a variety of maize plants in two adjacent plots. The average height and average dry weight of plants from the two populations were determined over a period of twenty weeks. The data is as shown in the table below.
BambooMaizeAge in weeksAverage height (Metres)Average weight (Grams)Average height
(Metres)Average weight
(Grams)21.3520.32044.01820.52968.24450.857812.16821.2781013.98011.71721214.19571.94201414.310252.17041614.410622.18951814.611272.19262014.612292.1908Between which two weeks did the greatest increase in weight occur in
- Bamboo plants
- Maize plants
- (i) Which of the two types of plants had a higher productivity by the end of the experiment
(ii) Give a reason for your answer in (b) (i) above
- Between weeks 14 and 18, the average height of the maize plants remained constant while average dry weight increased.
Explain this observation
- Suggest how the change in the average dry weight bamboo and maize
Plants would have been at week 22 if the experiment was continued.
- Why was it appropriate for this experiment to use
(i) Dry weight instead of fresh weight
(ii) Weight and height
- Describe how the average height and weight of the plants were determined in this experiment.
Average height
Average dry Weight
- Give a reason why secondary thickening does not occur in bamboo and maize plants
- (a) What is parasitism?
(b) Describe how the tapeworm is adapted to a parasitic mode of life
- (a) What is meant by the term digestion?
(b) Describe how the mammalian small intestine is adapted to its function