The Ecology of Populations

Contents & notes: what this topic covers

Under The Ecology of Populations, the JAMB Biology syllabus expects you to study:

• 5. The Ecology of Populations
• (a) Population density and overcrowding.
• (b) Adaptation for survival i. Factors that bring about competition ii. Intra and inter-specific competition iii. Relationship between competition and succession.
• (c) Factors affecting population sizes: i. Biotic (food, pest, disease, predation, competition and reproductive ability).
• ii. Abiotic (temperature, space, light, rainfall, topography, pressure, pH) etc.
• (d) Ecological succession i. primary succession ii. secondary succession

Study notes & guidance

Study The Ecology of Populations using a recommended Biology textbook that follows the JAMB syllabus. Work through the contents listed above one by one, make brief notes in your own words, and then practise as many questions on this topic as you can — in Biology, understanding and steady practice matter far more than memorising. Use the objectives below as a checklist: if you can do each one confidently, you have mastered this topic.

Objectives — candidates should be able to

After studying The Ecology of Populations, you should be able to:

1. Determine the reasons for rapid changes in human population and the consequences of overcrowding.
2. Compute/calculate density as the number of organisms per unit area.
3. Relate increase in population, diseases, shortage of food and space with intra- and inter-specific competition.
4. Determine niche differentiation as a means of reducing intra-specific completion.
5. Relate competition to succession.
6. Deduce the effect of these factors on the size of population.
7. Determine the interactions between biotic and abiotic factors, (e.g. drought or scarcity of water which leads to food shortage and lack of space which causes increase in disease rates).
8. Trace the sequence in succession to the climax stage of stability in plant population.

These objectives are from the official JAMB syllabus. Use them as a checklist — if you can do each one confidently, you have mastered this topic.

Source: official JAMB UTME Biology syllabus (IBASS, jamb.gov.ng). Reproduced for study use. Last checked: 17 Sept 2026. Always confirm the current syllabus on the official portal.