CSEC Biology Paper 2 January 2020 - Free CXC Past Paper with Answers

Figure 1 shows the internal structures of a generalized plant cell.

Figure 1. Diagram of the internal structures of a generalized plant cell

Name EACH of the structures labelled A, B, C, D, E and F.

Differentiate between plant cells and animal cells by identifying TWO differences. Explain how EACH difference is important to the plant's existence.

State the expected observation if EACH of the cell types (plant cell and animal cell) was placed in distilled water for 15 minutes. Suggest ONE reason for EACH observation.

Plant cell Observation Reason

Animal cell Observation Reason

Name the process which is responsible for the observation in (b) (i).

Describe the process by which the structure of the boy's eye will allow him to

read the book

observe his friends playing in the distance.

Name the type of corrective lens which would help the boy see distant objects clearly if he is nearsighted.

John is nearsighted but his sister Mary has normal vision. What would cause John's sight to be different from Mary's?

How would wearing corrective lenses/glasses allow John to see objects as clearly as Mary?

Explain why the appearance of the boy's eyes while seated under the shade of the tree would be different if he is seated in the sun.

Figure 3 is a simplified diagram of the carbon cycle.

Figure 3. The carbon cycle

Name the processes labelled A, B, C and D. A B C D

Recently, there has been an increase in human activities which resulted in the increase of atmospheric carbon dioxide. Suggest THREE human activities that could have contributed to the increasing levels of carbon in the ecosystem and for EACH activity, state ONE way by which it increases the carbon levels in the ecosystem.

Suggest THREE practices that can be adopted to reduce the impact of human activity on the carbon cycle.

Human activities can lead to an increase in greenhouse gases. Name TWO greenhouse gases other than carbon dioxide.

Complete the following table to compare the diseases hypertension and yellow fever for each characteristic given.

TABLE 2: COMPARISON OF HYPERTENSION AND YELLOW FEVER

Explain how vaccination works to prevent persons from becoming ill with yellow fever.

Discuss THREE strategies that can be used by hypertensive patients to control their signs/symptoms.

Describe how the human skin helps the body to keep cool on a hot, sunny day.

State ONE similarity and ONE difference between human beings and invertebrates in the ways they cool their bodies on hot days.

Persons with the inherited condition albinism do not produce the pigment (melanin) that gives the skin its dark colour.

Using the symbols A to represent a normal allele and a to represent the albino allele, draw a genetic diagram to illustrate how two heterozygous parents could produce an albino child.

Identify the genotype of the albino child.

State the probability of the albino child being produced.