CSEC Biology Paper 2 May/June 2019 - Free CXC Past Paper with Answers

Figure 1 shows apparatus that was set up to measure the rate of transpiration of a potted plant located in a room beside an open window, over 12-hour period.

Describe the procedure that uses the apparatus shown in Figure 1 to investigate the rate of transpiration of the potted plant within the 12-hour period.

State ONE precaution that should be taken to ensure that the results are accurate.

Suggest TWO factors that may affect the rate of transpiration of the potted plant.

The graph in Figure 2 was constructed using the results obtained from the investigation in (a) which measured the rate of transpiration over a 12-hour period.

Draw a suitable table and record the results presented in the graph in Figure 2.

During what time period was the rate of transpiration highest?

Suggest TWO reasons for the shape of the graph during EACH of the following time periods:

6 a.m. to 8 a.m.
9 a.m. to 11 a.m.
12 noon to 2 p.m.

Discuss how transpiration helps plants to move water from their roots to their leaves.

While absorbing water from the soil, plants absorb mineral salts such as magnesium, calcium and nitrogen. State ONE role of magnesium and ONE role of calcium in plants.

Magnesium

Calcium

Nitrogen is used by plants to make protein. Suggest TWO reasons why plants need protein.

Figure 3 is a diagram of the carbon cycle.

<image: Figure 3. The carbon cycle>

State the name of the processes numbered I to IV. I II III IV

Name ONE type of organism responsible for decomposing organic waste.

Explain TWO ways in which the type of nutrition carried out by the organism named in (b) (i) is different from that carried out by plants.

State TWO reasons why the type of organism named in (b) (i) is important in an ecosystem.

Suggest TWO reasons why carbon dioxide is described as a greenhouse gas.

With reference to the carbon cycle, suggest TWO strategies individuals can use to reduce the amount of carbon dioxide in the atmosphere.

Figure 4 shows a diagram of the human respiratory system. Label, on the diagram, the FOUR structures that are directly involved in breathing.

<image: Figure 4. Human respiratory system>

State how any THREE of the structures labelled in (a) function in breathing during inhalation.

Explain how any TWO features of the human lung make it an efficient respiratory surface.

Breathing rate can be affected by several factors. Explain how exercise and smoking may affect a person's breathing rate.

Effect of exercise
Effect of smoking

SECTION B Answer ALL questions.

Describe TWO events that occur in EACH of the following stages of meiosis I.

Prophase I
Anaphase I
Telophase I

Describe TWO events that occur in EACH of the following stages of meiosis I.

Prophase I

Anaphase I

Telophase I

Mutation and sexual reproduction are two processes which can lead to variation in the population of a species. State ONE way in which both processes are similar and TWO ways in which they differ.

Explain the difference between variation in a community and variation in a population, and suggest ONE way in which diversity benefits the community.

Briefly explain how bacteria may become resistant to antibiotics.

Describe the location and structure of the normal human female reproductive system.

A newly married couple wants to delay having children for a few years. Suggest ONE temporary contraceptive method that the couple could use to prevent pregnancy at EACH of the following stages.

Preventing fertilization

Preventing ovulation

Preventing implantation

Explain how EACH contraceptive method suggested in (b) works to prevent pregnancy at each of the following stages.

Preventing fertilization

Preventing ovulation

Preventing implantation

Preventing fertilization

Preventing ovulation

Preventing implantation

State the name of the final products of digestion for EACH of the following types of nutrients.

Carbohydrate

Protein

Fat/lipid

In addition to the macronutrients in (a), list three other types of nutrients in a diet that would promote the maintenance of good health.

Mary is a diabetic but her husband Marvin is not. Explain how the concentration of sugar in Marvin's blood is kept within the normal range several hours before AND after he eats a carbohydrate meal.

Before a carbohydrate meal

After a carbohydrate meal

Explain why Mary is advised to limit her consumption of simple carbohydrates.

CSEC Biology Paper 2 May/June 2019 Questions

Question 1 (25 marks)

Question 2 (15 marks)

Question 3 (15 marks)

Question 4 (15 marks)

Question 5 (15 marks)

Question 6 (15 marks)