Q: Some what which live off a host kill it, but most do not?
Options:
- (A) offspring
- (B) pets
- (C) poisons
- (D) fungi
- (E) Leptospirosis
- (F) bacteria
- (G) animals
- (H) organisms
A: So, my chain of thought: Some parasites kill their host, but most do not. Parasites are organisms which live off a host. Some organisms which live off a host kill it, but most do not. The answer is (H).

Q: _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: So, my chain of thought: 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. The answer is (A).

Q: What occurs when cell walls ease up?
Options:
- (A) root growth
- (B) air cools
- (C) dilation
- (D) sweating
- (E) Dehydration
- (F) recovery
- (G) Exfoliation
- (H) less water
A:
So, my chain of thought: Dilation occurs when cell walls relax. Slowly leg muscles ease up and shoulders relax. Dilation occurs when cell walls ease up. The answer is (C).