CXC CSEC exam guide: Human and Social Biology - Section A: Living Organisms and the Environment

CXC Human and Social Biology exam guide: Living Organisms and the Environment

CXC CSEC exam guide: Human and Social Biology

Section A- Living Organisms and the Environment

Specific Objectives

Students should be able to:

Explanatory notes


Describe the characteristics of living organisms;

Nutrition, respiration, excretion, growth, irritability, movement, reproduction


Compare the structures of an unspecialized plant and animal cell and selected microbes;

Basic structure of unspecialized plant cell, animal cell and microbes.

(a) Labeled diagrams of plant and animal cell.

(b) Microbes include:

(i) virus;
(ii) bacteria;
(iii) fungi.

(Link to Specific Objective D7)


State the functions of all cell structures;

Cell wall, cell membrane, nucleus, ribosomes, cytoplasm, mitochondria, vacuoles, chloroplasts, endoplasmic reticulum.


Identify selected cells which make up the human body;

Diagrams and features required:

  1. Epithelial cells;
  2. Sperm cells;
  3. Egg cells;
  4. Nerve cells;
  5. Muscle cells.
5. Explain the importance of cell specialization in human;

(a) Cell differentiation.

(b) Relation to cells to the organism as a whole.

6. Distinguish between osmosis and diffusion; *

Explain the importance of osmosis, diffusion and active transport in living systems;

Movement of substances across the cells.

  1. Osmosis as a special type of diffusion.
  2. Cell membrane as a partially permeable membrane.
  3. Movement of water from cell to cell.
  4.  Examples of osmosis occurring in plants and animals.
  5. Diffusion of gases in and out of a living cell.
  6. Experimental activity to demonstrate osmosis and diffusion in living cells.
  7. Active transport – movement of ions against a concentration gradient using energy.

(Link to Specific Objectives B 1.24, B1.26)

8. Explain the process of photosynthesis

(a) Definition of photosynthesis.

(b) Simple treatment involving word equation to summarize the process.

(c) Site of photosynthesis (chloroplast).

(d) Fate of products of photosynthesis.

9. Investigate the effect of light and chlorophyll on the production of starch*
10. Explain the ways in which other living organisms depend on plants directly or indirectly for food;

(a) Plants as producers.

(b) Human beings dependence on plants directly or indirectly for food.

11. Explain the principles of a food chain;

Definition of a food chain and trophic level;

names of organisms feeding at each tropic level (omnivore, carnivore, herbivore, producer, primary and secondary consumers);

reduction of available energy at each trophic level;

utilization of energy at each trophic level.

12. Construct a food chain from a selected habitat; Terrestrial and aquatic (marine and fresh water) habitats.
13. Identify the trophic level of organisms in the food chain;
14. Describe the recycling of carbon and nitrogen in nature.

The importance of recycling nitrogen and carbon in nature,

Nitrogen cycle, the up-take of nitrates by green plants and the formation of plant proteins;

inability of plants to use nitrogen in its unreactive forms;

the role of plants, animals and micro-organisms in the nitrogen cycle;

the role of legumes; the role of herbivores; the role of bacteria and fungi as decomposers.

Carbon cycle: the importance of CO₂ in photosynthesis;

examples of carbon compounds that release carbon when burnt;

the release of carbon dioxide during combustion, respiration and decomposition.


guest (not verified) 10 February 2011 - 12:39pm

Is this all the sections on the syllabus?

admin 10 February 2011 - 6:26pm

In reply to by guest (not verified)


This is one section of the syllabus. The exam guide for Human and Social Biology gives a break-down of all the sections on the syllabus.

In addition, it gives information on the organization of the exam.

RACH (not verified) 23 September 2011 - 5:16pm

i am a new student preparing to take the cxc in 2012 and this really helps a lot.i am sure that i will bhe well prepared by the time i take it with this kind of guide.

admin 22 October 2011 - 8:13am

In reply to by desmond (not verified)

Hello, we are not registering new members right now. We hope to begin registration again shortly.

aNDRE (not verified) 20 April 2012 - 2:43pm

I hope this helps becuz most time this does'nt really come in the exam

shoronia (not verified) 2 April 2013 - 1:12am

This site is very helpful I am sitting exam in January and I am so far behind

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