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Form 3 Biology Paper 2 End of Term 2 Examination 2022

Class: Form 3

Subject: Biology

Level: High School

Exam Category: Form 3 End Term 2 Exams

Document Type: Pdf

    

Views: 485     Downloads: 7

Exam Summary


NAME___________________________________________ ADM_______________ CLASS_______
BIOLOGY PAPER 2 FORM THREE (THEORY)
TIME: 2 HOURS
INSTRUCTIONS
1. This paper consists of two sections A and B. Answer All the questions in section A in the spaces provided.
2. In section B answer questions 6 (Compulsory) and either Questions 7 or 8 in the spaces provided.
SECTION A
1. The diagram below shows the traverse section of a young stem.
5.png
(a) Name the tissues labeled B and C (2mks)
B………………………………………………………………………………………. C……………………………………………………………………………………….
(b) What type of cells are found in the parts labeled D (1mk) ............................................................................................................................................................................................................................................................................................................
(c) State the function of the tissue labeled C and E (2mks) ............................................................................................................................................................................................................................................................................................................
(d) List two differences between the section above and the one that would be obtained from the root of the same plant (2mks) ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
(e) On the diagram above name the tissue that protects all the other tissues (1mk)

2. Study the homeostatic scheme below:
6.png
(a) Identify the hormones labeled A and B (2mk) ............................................................................................................................................................................................................................................................................................................
(b) Name the site of action of hormone A (1mk) ......................................................................................................................................................
(c) Identify the feedback labeled D (1mk) ......................................................................................................................................................
(d) Name the disease that is caused by a deficiency in hormone A (1mk) ......................................................................................................................................................
(e) State two symptoms of the disease you have named in (d) above (2mk) ............................................................................................................................................................................................................................................................................................................
(f) Distinguish between diabetes mellitus and diabetes insipidus (1mk) ……………………………………………………………………………………………………………………………………………………………………………………………………..
3. The diagrams below represent two plant cells A and B placed in two different solutions. Study the diagrams and answer questions that follow:
7.png
a) Identify the nature of solution into which each cell was placed. (2mk)
A …………………………………………………………………………………........ B ………………………………………………………………………………………
b) Name the physiological process responsible for the observed results. (1mk)
……………………………………………………………………………………….. c) Give the correct biological term used to describe cell A. (1mk) ………………………………………………………………………………………...
d) Describe what would happen if a red blood cell was placed in the solution in which cell B was placed. (2mk)
………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………
e) Explain why freshwater amoeba do not burst when placed in distilled water. (2mk)
………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………
4. To estimate the population size of crabs in a certain lagoon, traps were laid at random 400 crabs were caught, marked and released back into the lagoon. Four days later, traps were laid again and 360 crabs were caught. Out of the 360crabs, 90 were found to have been marked
(a) Calculate the population size of the crabs in the lagoon (3mks)
(b) What is the name given to this method of estimating the population size (1mk)
(c) State two assumptions made by the students during the investigation (2mks) ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………….
(d) Name two abiotic factors that can influence the population and distribution of the crabs in the lagoon (2mks) ............................................................................................................................................................................................................................................................................................................
5. a) Name the plant organs in which meiosis take place. (2mk)
……………………………………………………………………………………………………………………………………………………………………………………………..
b) Identify the figure below. (1mk)
8.png
c) Using the diagram, explain the meaning of double fertilization in flowering plants.
(1mk) ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………….
d) What happens to the structure above after fertilization? (1mk)
……………………………………………………………………………………………………………………………………………………………………………………
e) State three adaptations of fruits to animal dispersal. (3mk)
………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

SECTION B
6. In an experiment to investigate a certain process in a given plant species, the rate of carbon (IV) oxide consumption and the rate of carbon (IV) oxide released were measured over a period of time of the day. The results of the investigation are shown in the table below.
9.png
a) On the same axis plot graphs of volume of CO2 consumed and CO2 released against time. (8mks)
b) Name the biological process represented by
i) CO2 consumption: …………………………………………………...(1mk)
ii) CO2 release: ……………………………………….………………... (1mk)
c) Account for the shape of the curve for
i) CO2 consumption (2mks)
ii) CO2 release (2mks)
d) i) From the graph state the time of the day when the plant attains the compensation point. ………………………………………………………….(1mk)
ii) What is meant by compensation point? (1mk) …………………………………………………………………………………………………………………………………………………………………………….
e) Explain how temperature affects the rate of CO2 consumption in a plant. (1mk)
f) Under certain conditions CO2 concentration in blood of a mammal rises above normal.
i) State the two physiological changes that occur in the body to lower the CO2 level back to normal. (2mks)
………………………………………………………………………………………………………………………………………………………………
ii) Most CO2 is transported from tissues to the lungs within RBC and not in the plasma. State the advantage of this mode of transport. (1mk)
7. a) Describe how water molecules are absorbed from the soil and moves to the leaves in a tree. (10mk)
b) Describe the mechanism of inhalation in human beings. (10mk)
8. a) Describe the features and mechanisms that prevent self-fertilization in flowering plants. (10mks)
b) Explain any five adaptations of the ileum to the process of absorption. (10mks)

 

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