THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATION COUNCIL OF TANZANIA

ADVANCED CERTIFICATE OF SECONDARY EDUCATION EXAMINATION

133/1 BIOLOGY 1

(For Both Private and School Candidates)

Duration: 3 Hour Year: 2021

Instructions

1. This paper consists of section 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. 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) Briefly describe the stages of the oestrus cycle.

(b) Justify the need for the oestrus cycle in female animals.

2. (a) Find the Respiration Quotient (RQ) for a complete respiration of glucose.

(b) Giving seven points, justify the need for fermentation processes in animals.

3. Give four points to support each of the following facts:

1. Natural system of classification has never been achieved in the fullest sense.
2. Scientists prefer to use natural rather than artificial systems of classification.

4. (a) Eukaryotic cells possess many organelles with special structures suitable for performing specific functions. How does each of the following structure enable the respective organelle to perform its role?

1. Tonoplast in vacuole
2. Glycocalyx in plasma membrane
3. DNA in nucleus
4. Cristae in mitochondria

(b) Describe the "lock and key" model of enzyme action.

5. (a) State digestive roles that will be impaired if the pancreas is severely damaged. Give four points.

(b) Briefly describe what would happen to duodenal enzymes if the pH in the duodenum remained at 2.

6. (a) Why most of the reactions of the cell take place in the cytoplasm? Give four points.

(b) Why is cytoplasm an important part of the cell? Give six points.

7. Using well-labeled diagrams, describe the conduction of a nerve impulse along an unmyelinated neuron.

8. Describe the adaptation of the mammalian foetus, mountain dwellers, and divers to oxygen uptake. The mammalian fetus, high-altitude dwellers, and divers have developed remarkable adaptations to optimize oxygen uptake in their respective environments.

9. Figure 1 represents the changes in the level  hormones in blood during the course of menstrual cycle. Study the figure and answer the tocsin ms that follow:

Figure 1

1. Why are the hormones shown in Figure 1 important in the menstrual cycle?
2. Predict four hormonal changes which would have occurred if pregnancy had occurred on the 18^th day of menstrual cycle.

10. (a) How does xylem adapt to water transportation? Give six points

(b) Explain how capillarity force governs the upward movement of water and mineral salts

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: 2021

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) Viruses are considered to be non-living entities. Justify this statement by giving their five non-living characteristics.

(b) Giving one example in each case, describe ten economic importance of protoctists.

2. (a) Explain the role of major components of the homeostatic system.

(b) Describe how the hypothalamus controls body temperature in the human body.

3. (a) Describe the process of primary growth in plants.

(b) Explain how lateral branches and lateral roots are formed.

4. An experiment was conducted on pure breeding varieties of goats. The black-haired male and whitehaired female goats were crossed, and all the F₁ were black-haired. When the F₁ were selfed, F₂ had the following phenotypes: 

• 418 black-haired goats
• 106 grey-haired goats 
• 36 white-haired goats

Use a Punnett square to show the formation of F₁ and F₂.

5. Giving examples, explain how the following evidences support organic evolution:

1. Palaeontology
2. Comparative Morphology and Anatomy
3. Comparative Biochemistry
4. Comparative Embryology

6. Describe how primary and secondary ecological successions are brought about in ecosystems.