Ques and Ans: What happens to aquatic life if acidity is higher or lower than a narrow range?
Options:
- (A) Plant growth is reduced
- (B) They may not survive.
- (C) Aquatic life sinks
- (D) harm them
- (E) It is endangered
- (F) Damages them
- (G) Aquatic life moves to dry land
- (H) Aquatic life flourishes
(E)
Explanation for the Ans above: [[All life relies on a relatively narrow range of pH, or acidity. If the pH level is higher or lower, aquatic life is endangered. Aquatic life is endangered if acidity is higher or lower than a narrow range.]]

Ques and Ans: _carry signals that control sexual development and reproduction
Options:
- (A) sex hormones
- (B) electricity
- (C) nucleic acid
- (D) Most plants
- (E) animals
- (F) genes
- (G) dendrites
- (H) photons
(A)
Explanation for the Ans above: [[Sex hormones are chemical messengers that control sexual development and reproduction. Chemical messengers carry signals from one nerve branch to another. Sex hormones carry signals that control sexual development and reproduction.]]

Ques and Ans: What is the process of removing feces and excess water from the human body called?
Options:
- (A) recycling
- (B) salivation
- (C) waste production
- (D) excretion
- (E) Exfoliation
- (F) perspiration
- (G) Deposition.
- (H) Deposition
(D)
Explanation for the Ans above:
[[Excretion is the process of removing wastes and excess water from the body. Solid waste is called feces. Excretion is the process of removing feces and excess water from the body.]]