Logic of a solution: *Head hair is especially important in preventing heat loss from the body. Basically, heat is energy. Head hair is especially important in preventing energy loss from the body.*
*(C)*
The original question: *What does head hair prevent the loss of?
Options:
- (A) matter
- (B) chemicals
- (C) energy
- (D) sunlight
- (E) Nutrients
- (F) warmth
- (G) humidity
- (H) sweating*


Logic of a solution: *Arthropods have a life cycle with sexual reproduction. Sexual reproduction mixes the genes up more than is possible with asexual reproduction. Arthropods have a life cycle with mixing genes up.*
*(H)*
The original question: *Arthropods have a life cycle with what?
Options:
- (A) rapid expansion
- (B) survival
- (C) aerobic capacity
- (D) food and shelter
- (E) an organism's body
- (F) reproduce
- (G) barnacles
- (H) mixing genes up*


Logic of a solution: *Roundworms make up the phylum Nematoda. Within the Nematoda, a range of reproductive systems occur. A range of reproductive systems occur in roundworms.*
*(D)*
The original question:
*What has a range of sexual reproductive systems? 
Options:
- (A) Computer systems.
- (B) Most plants
- (C) animals
- (D) Roundworms.
- (E) mammals
- (F) Art reproductions.
- (G) insects
- (H) Stuffed toy bears.*