(question). What has a centralized nervous system with a brain?
Options:
- (A) Man
- (B) Birds
- (C) leeches
- (D) shark
- (E) evergreens
- (F) salmon
- (G) worms
- (H) pan
(answer). Fish have a centralized nervous system with a brain. Sharks are a type of fish. Sharks have a centralized nervous system with a brain.
The answer is (D)


(question). What shows evolution over geologic time above the level of the species?
Options:
- (A) speciation events
- (B) Leptospirosis
- (C) cliffs
- (D) rapid expansion
- (E) peachleaf willow
- (F) swamp vegetation
- (G) Darwin
- (H) RNA
(answer). Macroevolution is evolution over geologic time above the level of the species. Speciation events are thus examples of macroevolution. Speciation events show evolution over geologic time above the level of the species.
The answer is (A)


(question). What kind of animals has a water vascular system with tubed feet?
Options:
- (A) animals
- (B) starfish
- (C) reeds
- (D) insects
- (E) warm-blooded
- (F) sponges
- (G) sea coral
- (H) four limbs
(answer). Echinoderms have a unique water vascular system with tube feet. Echinoderms are represented by the starfish. Starfish have a unique water vascular system with tube feet.
The answer is (B)


(question). Sharks have as skeleton that contains
Options:
- (A) elastin
- (B) Epidermis
- (C) calcium
- (D) fur and fat
- (E) marrow
- (F) strength
- (G) all matter
- (H) collagen
(answer).

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Cartilage is a tough tissue that contains a protein called collagen. Sharks have a cartilage skeleton. Sharks have as skeleton that contains a protein called collagen.
The answer is (H)