CSEC Human and Social Biology Paper 2 January 2007 - Free CXC Past Paper with Answers

Figure 2 is a simplified diagram of parts of the nervous system.

On Figure 2, draw the THREE neurones which make up the simple spinal reflex arc.

Label the motor neurone as M.

Why is it considered dangerous to try one dose of heroin?

Why does a person taking heroin steadily increase the quantity taken?

Excessive use of alcohol is dangerous to the body. Explain how TWO named regions of the body are affected by alcohol consumption.

Figure 3 is a sketch of the human body showing two glands.

Name one hormone associated with EACH of the glands labelled in Figure 3. A: B:

Some hormones are slow-acting, while others act very rapidly. Name ONE hormone that acts rapidly and ONE that acts over a period of hours. Rapid: Slow acting:

Give the name and location of the gland responsible for the production of thyroxin. Name: Location:

Describe TWO effects of thyroxin on the human body when present at a) normal levels b) abnormal levels.

Describe TWO effects of thyroxin on the human body when present at normal levels

abnormal levels.

Complete Table 1 below to show what happens during inspiration.

TABLE 1

Explain why it is more difficult to breathe at high altitudes.

Which muscles contract to force air out of the thorax during deep breathing?

Briefly describe the control of breathing rate by the nervous system.

Name the structures labelled X and Y in Figure 4.

X: Y:

Explain how the structure of the left ventricle assists with its function.

Relate the structure of the arteries and veins to their respective functions.

Name the parts labelled A and B in Figure 5.

A: B:

Describe the functions of the medulla and ureter.

Medulla:

Ureter:

Explain why death occurs within ten days of kidney failure.

What is meant by EACH of the following genetic terms?

Sex-linked genes

Heterozygous

Genotype

Why is colour blindness much more common in males than in females?

By means of a genetic diagram, show the genotype and phenotype of the possible offspring produced by a father with normal vision and a mother who is heterozygous for colour vision.

Your neighbour, Mavis, is afraid of contracting dengue fever. Explain to her how the spread of dengue fever may be prevented in the community.

State TWO symptoms of dengue fever and explain how the disease is spread. Symptoms:

Method of spread:

Your neighbour, Mavis, is afraid of contracting dengue fever. Explain to her how the spread of dengue fever may be prevented in the community.

State how leptospirosis is spread and the organ in the body which is most affected by the disease. Method of spread:

Organ affected:

Explain TWO ways in which EACH of the following affects water resources.

Heavy industry

Agricultural activity

State ONE benefit of EACH of the following processes in the purification of water.

Exposure to ultraviolet light

Fluoridation

Chlorination

Aerification is an important step in water purification. Describe the process of aerification and give TWO benefits of the process.

State TWO uses of nitrogen in living organisms.

Figure 6 shows a part of the nitrogen cycle.

Figure 6: Part of the nitrogen cycle

Identify the factors labelled A, B and C.

Use the nitrogen cycle to explain why it would be unwise for man to destroy all bacteria on earth.

State THREE uses of water in the human body.

Write, in correct sequence, the structures through which water passes on the way from the mouth to the circulation of the blood.

Explain why prolonged diarrhoea can be dangerous.

Draw a diagram of a section through a villus. On the diagram label FOUR of the following parts: a) Blood vessels b) Lymph vessels c) Epithelial cells d) Lacteal e) Blood capillaries

State TWO functions of the epithelial cells of the villus.

Define the term 'diabetes mellitus'.

Define the term 'diabetes mellitus'.

State THREE symptoms of diabetes mellitus.

Differentiate between Type I and Type II diabetes mellitus.

Explain how Type II diabetes mellitus can be brought on by obesity.

Suggest how TWO named forms of therapy, OTHER THAN drugs, can be used to manage diabetes mellitus.

Name THREE materials that are commonly recycled.

Name THREE materials that are commonly recycled.

For ONE of the materials named in (a) (i) above, explain how the recycling process reduces pollution, OTHER THAN by direct reduction.

As a Health Inspector, you visit a remote village not serviced by running water or a garbage collection system. There is garbage all over the village. What advice would you give the villagers about the proper handling and disposal of refuse?