Thyroxine and adrenalin are examples of hormones which control?

1. Analyze the question The question asks what thyroxine and adrenalin (adrenaline) control. Both are hormones, so we need the option that fits the role of hormones in the body.

2. Explain the concept

• Thyroxine is produced by the thyroid gland. It regulates metabolic rate, growth, and development. Too little or too much changes how a person behaves, with sluggishness and dullness in one case and restlessness and nervousness in the other.
• Adrenalin is produced by the adrenal glands. It prepares the body for "fight or flight" by raising heart rate, blood pressure, and blood sugar. It directly shapes how we respond to danger, fear, and excitement.

Hormones are chemical messengers that coordinate body activities and influence behaviour.

3. Step-by-step elimination

• A. Blood grouping: This is determined by genes (A, B, AB, O alleles), not by hormones. ✗
• B. Tongue rolling: This is an inherited trait controlled by genes. ✗
• C. Behavioural patterns: Thyroxine and adrenalin both influence mood, alertness, and reactions such as fear and aggression. ✓
• D. Colour variation: This is mainly genetic (e.g. skin or coat colour), and is not controlled by these two hormones. ✗

4. Answer The correct option is C. behavioural patterns.

5. Exam tip Blood group, tongue rolling, and colour variation are all inherited (genetic) traits. Hormones such as thyroxine and adrenalin are chemical coordinators that affect physiology and behaviour. When a JAMB question pairs hormones with traits, ask yourself: "Is this inherited or hormone-controlled?"