question... _ bind to allergens.
Options:
- (A) to stay warm
- (B) mammals
- (C) fur and fat
- (D) animals
- (E) protect them
- (F) Most plants
- (G) Antibodies
- (H) Chemical energy
answer... Antibodies are large, Y-shaped proteins that recognize and bind to antigens. Allergens are also called Antigens. Antibodies bind to allergens.
The answer is (G)

question... How do some insects communicate?
Options:
- (A) sound
- (B) sensory neurons
- (C) Decibels
- (D) electronic waves
- (E) progesterone
- (F) Vibrates
- (G) pheromones
- (H) radio waves
answer... Ants communicate with chemicals called pheromones. Ants are of extreme importance in the insect world. Some insects communicate with chemicals called pheromones.
The answer is (G)

question... What do mammals use their body hair or fur to conserve?
Options:
- (A) food
- (B) energy
- (C) warm
- (D) warmth
- (E) strength
- (F) sunlight
- (G) water
- (H) health
answer...
Mammals conserve body heat with their hair or fur. Heat is emitted energy. Mammals conserve body energy with their hair or fur.
The answer is (B)