WAEC 2020 Biology · Question 5

Use the list of insects below to answer the question below; I. Cotton stainer II. Honeybee III. Termite IV…

Question

Use the list of insects below to answer the question below; I. Cotton stainer II. Honeybee III. Termite IV. Weevil The insects whose activities are both beneficial and harmful to humans are;

A.I and II
B.II and III
C.II and IV
D.III and IV

Answer: B. II and III

Explanation written with AI and checked against the answer key

Analyze the question: We need insects whose activities are both beneficial and harmful to humans, not just one or the other.

Go through each insect:

I. Cotton stainer: It feeds on cotton bolls and stains the lint, so it is a pest. It has no real benefit to humans. Harmful only.
II. Honeybee: It gives honey and wax and pollinates crops (beneficial). It can also sting people and sometimes disturbs farm workers (harmful). Both.
III. Termite: It destroys wooden structures, crops and paper (harmful). It also aerates and enriches the soil, and its alates (winged termites) are eaten as food by many Nigerians and used as feed for poultry and fish (beneficial). Both.
IV. Weevil: It destroys stored grains, beans and cereals. It is harmful only.

Conclusion: The insects with both beneficial and harmful effects are II (honeybee) and III (termite).

Exam tip: Remember that a "both" question needs two sides. Think of cotton stainers and weevils as pure pests (crops and stored produce). Honeybees and termites are the classic "double-role" insects: honeybees give honey but sting, and termites give food and soil improvement but destroy wood.

AI can make mistakes. Report anything that looks wrong.