Heredity

Contents & notes: what this topic covers

Under Heredity, the JAMB Biology syllabus expects you to study:

• 2. Heredity a) Inheritance of characters in organisms
• (i) Heritable characters
• (ii) Non-heritable characters b) Chromosomes – the basis of heredity
• (i) Structure
• (ii) Process of transmission of hereditary characters from parents to offsprings.
• c) Probability in genetics and sex determination.
• d) Application of the principles of heredity in: i) Agriculture
• (ii) Medicine e) Sex – linked characters e.g. baldness, haemophilia, colour blindness, etc.

Study notes & guidance

Study Heredity 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 Heredity, you should be able to:

1. Determine heritable and non-heritable characters with examples.
2. Illustrate simple structure of DNA
3. Illustrate segregation of genes at meiosis and recombination of genes at fertilization to account for the process of transmission of characters from parents to offsprings.
4. Deduce that segregation of genes occurs during gamete formation and that recombination of genes at fertilization is random in nature.
5. Analyze data on cross-breeding experiments.
6. Apply the principles of heredity in the production of new varieties of crops and livestock through cross- breeding.
7. Deduce advantages and disadvantages of out- breeding and in-breeding.
8. Analyze elementarily the contentious issues of genetically modified organisms (GMO) and gene therapy and biosafety.
9. Apply the knowledge of heredity in marriage counselling with particular reference to blood grouping, sickle-cell anaemia and the Rhesus factors.
10. Describe the significance of using recombinant DNA materials in the production of important medical products such as insulin, interferon and enzymes.
11. Identify characters that are sex linked.

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.