Ques:[What unwanted creature would be found on the surface of a human body using it as a host?
Options:
- (A) Tapeworm.
- (B) Leeches.
- (C) Pesticides
- (D) animals
- (E) insects
- (F) Hookworm
- (G) bacteria
- (H) Bracelet.]
Ans:[Some parasites live on the surface of their host. Leeches are external parasites. Leeches are on the surface of the host .
(B)]

Ques:[Cells with damaged dna are more likely to divide when exposed to what?
Options:
- (A) harmful substances
- (B) apoptotic genes
- (C) sulfur dioxide
- (D) a tumor suppressor
- (E) Electrical energy
- (F) heat or cold
- (G) immune system
- (H) a carcinogen]
Ans:[Oncogenes promote the division of cells with damaged DNA. Carcinogenic or oncogenic effects cause cancer. Carcnogenic substances can promote division of cells with damaged DNA.
(H)]

Ques:[What can be reduced when a population suddenly gets much smaller?
Options:
- (A) Pollution
- (B) The size of the Earth
- (C) Greenhouse gasses
- (D) The size of bottlenecks
- (E) The size of the environment
- (F) Genetic variation
- (G) Plant growth is reduced
- (H) Quality of life]
Ans:[Bottleneck effect occurs when a population suddenly gets much smaller. Genetic variation can be reduced by random genetic drift, population bottlenecks, founder effect. Genetic variation can be reduced when a population suddenly gets much smaller.
(F)]

Ques:[What kind of animal can live in large colonies and have complex behaviors?
Options:
- (A) arthropods
- (B) warm-blooded
- (C) birds
- (D) mammals
- (E) animals
- (F) honeybees
- (G) fur seals
- (H) fish]
Ans:
[Insects may live in large colonies and have complex social behaviors. Insects are just part of the Arthropod subdivision. Arthropods may live in large colonies and have complex social behaviors.
(A)]