q: What is needed for changes to occur?
Options:
- (A) exercise
- (B) mutations
- (C) growth
- (D) healthy animals
- (E) environment
- (F) evaporation
- (G) Exfoliation
- (H) births
a: (B)... Explanation: Mutations are essential for evolution to occur. Evolution Change through time. Mutations are essential for changes to occur. That's why the answer is (B).

q: What uses semiochemicals in urine to mark territory?
Options:
- (A) koalas
- (B) bacteria
- (C) humans
- (D) dogs
- (E) bears
- (F) cats
- (G) the Sun
- (H) rabbit
a: (D)... Explanation: Male dogs use pheromones in urine to mark their territory. Pheromones are a sub-category of semiochemicals. Male dogs use semiochemicals in urine to mark their territory. That's why the answer is (D).

q: Which of these trees seasonally sheds its leaves?
Options:
- (A) gone forever
- (B) Exfoliation
- (C) Most plants
- (D) Mulberry
- (E) ligt
- (F) vegetation
- (G) Heavy rains
- (H) homogenous
a: (D)... Explanation: Plants that shed their leaves seasonally each year are called deciduous plants. Mulberry trees are deciduous. Mulberry trees seasonally shed their leaves. That's why the answer is (D).

q: What supplement would a human take to aid in breaking down food?
Options:
- (A) sweating
- (B) Energy
- (C) Enzymes.
- (D) Calcium supplements.
- (E) Energy.
- (F) Antacid.
- (G) Protein supplement.
- (H) evaporation
a:
(C)... Explanation: Digestion is the process of breaking down food into components the body can absorb. Digestive enzymes are necessary for a complete digestion. Enzymes break down food into components the body can absorb. That's why the answer is (C).