What has a nervous system?
Options:
- (A) Nerve tonic
- (B) Jellyfish
- (C) Air
- (D) fur seals
- (E) Cardiovascular system
- (F) animals
- (G) chickens
- (H) elephants
--
Let's think first: Most invertebrates have a nervous system. Jellyfish and insects are invertebrates. Jellyfish have a nervous system.... So the answer is [(B)]

What helps to insulate and protect the body?
Options:
- (A) tail fins
- (B) Animal fur
- (C) fur seals
- (D) keratin
- (E) nitrogen
- (F) snow
- (G) Epidermis
- (H) poultry
--
Let's think first: Hair helps to insulate and protect the body. Hair is composed of the protein keratin. The protein keratin helps to insulate and protect the body.... So the answer is [(D)]

What harms the respiratory and circulatory systems?
Options:
- (A) oil
- (B) rain
- (C) sulfur
- (D) cars
- (E) tires
- (F) coal
- (G) tar
- (H) bicycles
--
Let's think first: Air pollution harms the respiratory and circulatory systems. Cars are a significant source of air pollution. Cars harm the respiratory and circulatory systems.... So the answer is [(D)]

Where do all adult echinoderms live?
Options:
- (A) soil
- (B) desert
- (C) freshwater
- (D) fossils
- (E) water
- (F) Earth
- (G) small
- (H) aquariums
--
Let's think first: Adult echinoderms have radial symmetry. All animals with radial symmetry live in water. All adult echinoderms live in water.... So the answer is [(E)]

What does pollen consist of tiny grains of?
Options:
- (A) it helps plants in growing
- (B) the female sexual organs
- (C) Something with exactly eight protons
- (D) seeds
- (E) Microscopic organisms
- (F) the male sex cells of plants
- (G) bees
- (H) sub-units of species
--
Let's think first: Pollen consists of tiny grains that are the male gametes of plants. Animals that reproduce sexually produce sex cells, or gametes. Pollen consists of tiny grains that are the male sex cells of plants.... So the answer is [(F)]

Cytokinesis is the final stage of cell division in what items?
Options:
- (A) infected
- (B) insects
- (C) animals
- (D) Plants.
- (E) fungi
- (F) plants
- (G) food
- (H) parasites
--
Let's think first: Cytokinesis is the final stage of cell division in eukaryotes as well as prokaryotes. All plants are eukaryotes. Cytokinesis is the final stage of cell division in plants.... So the answer is [(D)]