“The maximum concentration of harmful chemicals accumulates in human beings?” State the phenomenon involved and justify this statement.

(b) What is • Phototropism and • Geotropism? With labelled diagrams describe an activity to show that light and gravity change the direction that plant parts grow in. (b) Mention the role of each of the following plant hormones: • Auxin • Abscisic acid.

Updated 1/12/2026

Name the three major regions of human brain. Which part of brain maintains posture and equilibrium of the body?

Updated 1/12/2026

What is the function of genes in an organism?

Updated 1/12/2026

Describe briefly four ways in which individuals with a particular trait may increase in population.

Updated 1/12/2026

“Variations that confer an advantage to an individual organism only will survive in a population.” Justify.

Updated 1/12/2026