THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATIONS COUNCIL OF TANZANIA CERTIFICATE OF SECONDARY EDUCATION EXAMINATION

BIOLOGY

(For Both School and Private Candidates)

Time: 3 Hours Year: 2006

SECTION A

1. For each of the items (i) - (x) choose the correct answer from among the given alternatives and write its letter beside the item number.

(i)Which of the following are the non-living parts of a cell?

1. Cell wall and nucleus
2. Cell wall and vacuoles
3. Cytoplasm and endoplasmic reticulum
4. Cytoplasm and vacuole
5. Cell wall and ribosome

(ii)Which one of the following is a group of animal tissues?

1. Muscles, blood, nerve and epithelia
2. Eye, muscles, skin and blood
3. Cardiac muscles, skin, liver and blood
4. Blood, muscles, skin and kidney 
5. Liver, pancreas, lymph and ear

(iii)Diabetes mellitus is associated with:

1. Too much insulin in the blood
2. Too much glucose in the lymph
3. High glycogen level in the blood
4. Under secretion of insulin in the blood
5. Too little glucagon in the blood

(iv)The Graph below shows changes in dry weight of a germinating seed.

The reasons for the decrease in dry weight and final i" V weight of the germinating seed are:-

1. Stored food being used for photosynthesis and increase due to respiration;
2. Respiration from stored food and increase due to ability to make food by photosynthesis;
3. Respiration from stored food and increase due to absorption of water;
4. Excretion and respiration and increase due to absorption of water;
5. Excretion and increase due to respiration.

Fig. 1

(v) The best distinction between diastolic and systolic blood pressure is that:

1. Diastolic blood pressure is caused by contraction of ventricles while systolic blood pressure is caused by contraction of auricles.
2. Diastolic blood pressure causes blood from contracting auricles to flow into ventricles while systolic blood pressure causes blood from contracting ventricles to flow into pulmonary artery and aorta.
3. Diastolic blood pressure is the same as systolic blood pressure. Therefore there is no distinction.
4. Diastolic blood pressure is lower than systolic blood pressure.
5. Diastolic blood pressure is common.

(vi) Which of the following prevents surfaces of the articulating bones from being worn out by friction?

1. Capsular ligament
2. Synovial membrane
3. Articular cartilage
4. Tendon
5. Synovial capsule

(vii) Figure 2 represents a of a small mammal.

Examine Figure 2 below and answer the questions that follow:

Fig. 2

1. ventral view of cervical vertebra
2. anterior view of thoracic vertebra
3. anterior view of atlas vertebra
4. side view oflumbar vertebra
5. anterior view of caudal vertebra

(viii)The structure labelled A is called:

1. Vertebra arterial canal
2. Posterior facet
3. Neural arch 
4. Anterior
5. Neural facet

(ix) Refer to Figure 3

Fig. 3

Figure 3 is a:

1. Transverse section through a monocot root
2. Transverse section through a dicot stem
3. Transverse section through a dicot root
4. Transverse section through a monocot stem 
5. Longitudinal section of a dicot stem

(x) Observe the punnet square below:

The possible gene combination in square number 3 of Figure 4 above is:

1. bcBc 
2. bbCc 
3. BbCc
4. Bbcc 
5. bbcc

2. Match the items in List A with the responses in List B by writing the correct response beside the item number.

SECTION B

3.(a) Complete the Table below by writing the location of the given joint in the body.

(b)Study Figure 5 below and answer the questions that follow:

Fig. 5

What type of joint does Figure 5 represent?

(i)Name the structures labelled A - F 

(ii) State the function of structure E

4.(a) (i) Define the term mitosis.

(ii) Outline the significance of mitosis to organisms.

(b) Define the following terms and give an example of an organism where each takes place.

(i)Complete metamorphosis

(ii)Incomplete metamorphosis

(iii) Ecdysis

(c) Distinguish diffuse growth from localized growth and name kingdom(s) that exhibit each kind of growth.

5.(a) Explain the adaptation of the lungs for gaseous exchange.

(b) What is the biological importance of shivering during cold weather?

(c) Explain why some trees are killed when a ring of bark is removed from their stems.

6.(a) By means of a suitable table show the source and role of the following mineral elements to the growth of plants and the deficiency symptom• for each element. 

(i) Phosphorous

(ii)Nitrogen

(iii)Calcium

(iv)Iron

(b)Name two enzymes in the human gut which break down proteins, each case state the site of production, the substrate and products.

7. (a) Examine Figure 6 and answer the questions below it.

Fig. 6

(i)Name the structures labelled A - E.

(ii)State the functions of structures F and H.

(b) What does Figure 6 represent?

8.(a) Name four (4) different types of consumers found in natural ecosystem. Figure 7 below represents a pyramid of numbers.

Fig. 7

(i) Place the following organisms in their appropriate trophic levels. Indicate by letters A — E algae, large fish, human being, small fish, and zooplankton.

(ii) Give the name of the highest trophic level in this pyramid.

9.(a) How do cultural practices affect reproductive health in Tanzania? Explain your answer using two (2) cultural practices.

(b) Mention two (2):

(i) Non-communicable reproductive tract infections (RTIs) 

(ii) Non-communicable reproductive tract diseases (RTDs)

10.(a) State Mendel's first law.

(b) Use the words "homozygous", "heterozygous", "dormant" and "recessive" (where suitable) to describe the following gene combinations: 

(i) Bb

(ii) BB

(iii) bb

(c) Explain the meaning of:

(i)sex limited character

(ii)sex linked inheritance

(iii)sex determination

(d) A married couple has four girl children but no boys. Does this mean that the husband produces X-chromosomes only? 

SECTION C

11. (a) What does delaying sex mean?

(b) List the advantages of abstaining from sexual intercourse during adolescence.

(c) Define the term "assertive behavior" and explain its importance in a risk behavior and situation.

(d) Briefly explain how to care and support people living with HIV and AIDS.

12. (a) What is the composition of mammalian blood?

(b) Explain clearly the functions of mammalian blood.

13. (a) Outline the ways by which the human body prevents invasion and infection by disease causing micro organisms.

(b) Discuss the causes, mode of transmission and control of malaria.