Question

(8) barnacles grow on a whale without harming the giant mammal.
a mutualism
b commensalism
c predation
d parasitism
(9) lice live on human hair and cause problems for humans
a mutualism
b commensalism
c predation
d parasitism

Explanation:

• For question (8): Commensalism is a symbiotic relationship where one organism benefits (barnacles get a place to live and access to food as the whale moves) and the other (whale) is neither helped nor harmed.
• For question (9): Parasitism is a relationship where one organism (lice) benefits (gets food - human blood) and the other (human) is harmed (gets problems like itching, discomfort).

Answer:

1. B. commensalism
2. D. parasitism