CSEC Human and Social Biology Paper 2 May/June 2015 - Free CXC Past Paper with Answers

The human body is composed of about 70% water. All of our body reactions take place in a fluid medium.

State TWO functions of water OTHER THAN it is the medium in which reactions occur.

Apart from water, the human body needs a balanced diet in order for it to perform at its best.

What is meant by the term 'balanced diet'?

Name TWO nutrients which must be present in a balanced diet to provide the energy for a person's activities.

Amari visits the National Science Centre and sees the following experiment being conducted.

A sample of a substance is divided into two parts, one part placed in Test Tube 1 and the other part in Test Tube 2. Benedict's solution is added to both test tubes and the test tubes are shaken. Test Tube 1 is then heated.

The colour changes from blue to orange-red in Test Tube 1. Name the nutrient that is MOST likely present in the sample.

Would there be a colour change in Test Tube 2? Give a reason for your answer.

A survey is conducted on four groups of secondary school students on the number of servings of carbohydrates, fats and proteins that they eat during a one-week period. Table 1 shows these results. Study the information in Table 1 and answer the questions that follow.

TABLE 1: RESULTS OF A SURVEY AMONG FOUR GROUPS OF STUDENTS

Group of Students	Number of Servings of Carbohydrate	Number of Servings of Fat	Number of Servings of Protein
A	125	115	60
B	100	80	81
C	60	7	30
D	60	50	140

Which group of students had the MOST balanced diet? Give a reason for your answer.

Which group of students would be MOST prone to becoming obese? Give a reason for your answer.

Other than diet and exercise, suggest ONE factor that could contribute to obesity.

Figure 1 shows a diagram of a long bone.

Figure 1. Diagram of a long bone

Identify the parts labelled A and B. Write your answers on Figure 1.

State ONE benefit of bones being hollow rather than solid.

Name TWO raw materials required for the process of photosynthesis and ONE product of photosynthesis.

Raw materials Product

Cindy de-starches (starch removed from the leaf) a variegated leaf and then exposes it to light for several hours. She then tests the leaf for starch using iodine.

What are the expected results of her experiment? Explain your answer.

Figure 2 shows a food web.

Figure 2. A food web

Identify the group of organisms that possesses the GREATEST amount of biomass, and suggest the role that they play in the food web.

Organism Role

Explain why each subsequent trophic level possesses LESS energy than the previous level.

Suggest ONE consequence of the parrots being removed from the food web shown in Figure 2.

Identify the LARGEST source of air pollutants in the world today.

Name TWO gases that contribute to global warming.

What is the function of breathing in humans?

Fredrick is training for a track and field event at school. His coach tells him he needs to increase his vital capacity.

State what is meant by the term 'vital capacity'.

To increase his vital capacity, the coach recommends that Fredrick increases his exercise regime and avoid smoking. Explain the effects of exercise and smoking on his vital capacity.

Fredrick's team-mate advises him to start training at higher altitudes in preparation for his next race. Would training at a higher altitude improve his performance? Explain your answer.

Fredrick trains in a city that has polluted air. Will this adversely affect his performance? Give a reason for your answer.

Complete the following sentences by choosing the correct words from the list provided in brackets.

(blood pressure, systole, ventricles, atria, diastole)

When the chambers of the heart contract, this is called ____________________________________. When they relax, this is called ____________________________________. These alternating contractions and relaxations are necessary to force the blood through the blood vessels.

Plaque on the walls of arteries causes the hardening of the arteries.

Name the disease that describes the condition of hardening of the arteries and state ONE symptom of this disease.

Disease Symptom

As a result of the disease named in (b) (i) above, the internal diameter of the artery is reduced and this could lead to the development of hypertension. Name TWO factors that may contribute to hypertension.

The arteries leading to Brian's brain are becoming clogged. Briefly describe the effects that these clogged arteries would have on Brian's brain, and hence on Brian.

Hypertension is often linked to diabetes mellitus. Figure 3 shows the relationship between blood glucose levels and meals, of two persons, Axel and Golda.

Figure 3. Relationship between blood glucose levels and meals, for two persons

Which person, Axel or Golda, is MOST likely suffering from diabetes mellitus? Explain your answer.

Explain ONE way in which genetic engineering has assisted in the treatment of diabetes mellitus.

SECTION B

Answer ALL questions in this section.

Name the process by which eggs and sperms are made and state the importance of this process to fertilization.

Name TWO processes by which genetic variation occurs in humans and state ONE advantage of genetic variation.

Hosé and Maria are a young married couple. Hosé is just starting a new job in which there are many opportunities for promotion but for the time being is not making very much money. Maria is returning to school to study nursing. Maria’s parents advise the young couple to seek family planning counselling.

Suggest THREE advantages to Hosé and Maria of practising family planning.

Discuss THREE ways in which family planning benefits a country at large and not just the nuclear family.

The housefly is an insect which transmits pathogens from waste or faecal matter to foods thus causing diseases. Figure 4 shows the life cycle of the housefly.

Figure 4. Life cycle of the housefly

Name the stages labelled A and B and identify the duration of the processes labelled I, II, III and IV in Figure 4. Write your answers on Figure 4.

After Betty Bob’s graduation dinner, she becomes ill and the doctor suggests that she is suffering from gastroenteritis. Suggest THREE signs/symptoms that Betty Bob may have and advise her of the causative agent for gastroenteritis.

Typhoid is a disease that can also cause gastroenteritis. Suggest ONE OTHER disease that can cause gastroenteritis and explain TWO measures that could be used to prevent the occurrence of gastroenteritis.

CSEC Human and Social Biology Paper 2 May/June 2015 Questions

Question 1 (15 marks)

TABLE 1: RESULTS OF A SURVEY AMONG FOUR GROUPS OF STUDENTS

Question 2 (15 marks)

Figure 1. Diagram of a long bone

Figure 2. A food web

Question 3 (15 marks)

Question 4 (15 marks)

Figure 3. Relationship between blood glucose levels and meals, for two persons

Question 5 (15 marks)

Question 6 (15 marks)

Figure 4. Life cycle of the housefly