THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATIONS COUNCIL OF TANZANIA

ADVANCED CERTIFICATE OF SECONDARY EDUCATION EXAMINATION

133/1 BIOLOGY 1

(For Both School and Private Candidates)

Time: 3 Flours  Year: 2022

Instructions

1. This paper consists of sections A and B with a total of ten (10) questions.
2. Answer all questions in section A and two (2) questions from section B.
3. Section A carries seventy (70) marks and section B carries thirty (30) marks.
4. Except for diagrams which must be drawn in pencil, all writing should be in blue or black ink.
5. Cellular phones and any unauthorised materials are not allowed in the examination room,
6. Writ your Examination Number on every page of your answer booklet(s).

SECTION A (70 Marks)

Answer all questions in this section. Each question carries ten (10) marks.

1. (a) A scientist placed 2 cm³ of starch solution in a test tube followed by 2 cm³ of saliva which was boiled to 75 ^°C. He then carried out starch test and observed a positive result. Briefly explain the observation.

(b) Eukaryotes have cells with organelles bound by membrane(s). Why is it advantageous for the organdies to be bound by the membrane(s)? Give three points.

2. (a) A biologist found some new insects which were supposed to be placed in the taxa. Among the tools which a biologist demanded for this work was a biological key. Why do you think a biologist needed a biological key? Give one point.

(b) Suppose that you have been assigned to construct a Dichotomous Key;

1. Describe the procedure you would follow.
2. How would you use the key constructed to classify the organisms?

3. (a) What would happen to an organism if its nervous system is severely damaged? Give four points.

(b) Figure 1 is a part of a neuron. Study it carefully and then answer the questions that follow:

Figure 1

1. Identify the type of neuron presented in Figure 1.
2. Which feature has helped you to make identification in (b) (i)?
3. What would happen to the neuron if each of the parts labeled A and B is severely damaged? Give two points for each.

(b) Explain how electron transport takes place in the photosystems I (PSI) and II(PSII).

5. (a) Why is it necessary for a respiratory surface to have each of the following features?

1. Large surface area to volume ratio
2. Moist surface
3. Thin membrane
4. Permeable membrane

(b) Glycolysis leads to the formation of pyruvic acid. How is the pyruvic acid converted to ethanol? Explain by giving two points.

6. (a) What would happen to a cell if its membrane lacks antigens? Give two points.

(b) In what ways is water important to plants? Give four points.

7. Figure 2 represents a vertical section through an angiosperm ovary at the beginning of fertilization. Study it carefully and then answer the questions that follow:

Figure 2

(a) Using the given labels:

1. list in correct order the parts of the ovary through which the pollen tube must grow in order to reach the embryo sac.
2. identify a part which performs similar function as the umbilical cord in human being.

(b) If fertilization occurs successful:

1. which part of the seed/fruit would develop from each of the parts labelled B, D, G and F?
2. what will be the fate of each of the pads labelled A and I?

SECTION B (30 Marks)

Answer two (2) questions from this section. Each question carries fifteen (15) marks

8. The release of energy from a glucose molecule occurs in three stages namely: glycolysis, Krebs' cycle and electron transport chain. Identify two essential features of each slue and explain how electron transport chain occurs in aerobic respiration.

9. Why should a mammalian placenta be formed immediately after implantation? Explain by giving six points.

10. Oxygen taken in through human nose enters the lungs and then it is transported to all parts of the body. Describe three ways in which oxygen is transported in human body.

THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATION COUNCIL OF TANZANIA

ADVANCED CERTIFICATE OF SECONDARY EDUCATION EXAMINATION

 133/2 BIOLOGY 2

(For Both Private and School Candidates)

Duration: 3 Hour Year: 2022

Instructions

1. This paper consists of six(06) questions.
2. Answer five(05) questions
3. Each question carries twenty(20) marks.
4. All writing must be in black or blue ink except drawings which must be in pencil
5. Communication devices and any unauthorized are not allowed in the examination room
6. Write your Examination Number on every page of your answer booklet(s).

1. (a) In five points, describe the structural similarities and differences between the bodies of birds and mammals.

(b) Explain how amphibians adapt to their environments.

2. Describe the process of osmoregulation by Anti-Diuretic Hormone (ADH) in the human body.

3. (a) Explain internal and external factors that affect seed germination.

(b) With the aid of a diagram, describe five events which occur during the telophase stage of mitosis.

4. A cross between pure yellow testa and green testa bean seeds produced yellow testa seeds in F₁. On selfing the F₁ plants, F₂ had the phenotypes shown in the following table:

Carry out genetic crosses to show the phenotype and genotype of F₁ and F₂

5. (a) Briefly describe four theories of the origin of life.

(b) Outline strengths and weaknesses of each of the theories described in 5(a).

6. (a) Giving an example in each, describe the interdependence of the following groups of organisms in the ecosystem:

(b) In five points, explain how energy flows within an ecosystem.