What feature allows frogs to absorb substances from the environment?
Options:
- (A) four limbs
- (B) poison dart frog
- (C) hydrate their cells
- (D) permeable skin
- (E) layers of fat
- (F) a cuticle
- (G) predators
- (H) double eyelid
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Let's think first: Amphibians have permeable skin that easily absorbs substances from the environment. All frogs are amphibians. Frogs have permeable skin that easily absorbs substances from the environment.... So the answer is [(D)]

Atoms make up many things, like what?
Options:
- (A) glass
- (B) matter
- (C) A computer
- (D) Fuel cells
- (E) copper
- (F) viruses
- (G) Light
- (H) Energy
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Let's think first: Viruses are usually considered to be nonliving. All matter, living and nonliving, is made up of atoms. Viruses are made up of atoms.... So the answer is [(F)]

What are behavior that is intended to attract a mate?
Options:
- (A) a doorbell
- (B) firm hugs
- (C) Complex rituals
- (D) Riding a bike
- (E) Behaviour modifications
- (F) Magnets
- (G) honeybees
- (H) Friendship
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Let's think first: Courtship is behavior that is intended to attract a mate. Complex courtship rituals precede mating. Complex rituals are behavior that are intended to attract a mate.... So the answer is [(C)]

Where do leeches live in relation to their hosts?
Options:
- (A) In their beds
- (B) body water
- (C) competing for resources
- (D) In their shoes
- (E) loose soil
- (F) In their intestines
- (G) important habitats
- (H) On their surface
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Let's think first: Some parasites live on the surface of their host. Leeches are external parasites. Leeches live on the surface of their hosts.... So the answer is [(H)]

Which is higher on the food chain?
Options:
- (A) insects
- (B) animals
- (C) humans
- (D) glucose
- (E) decomposers
- (F) herbivores
- (G) producers
- (H) consumers
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Let's think first: Consumers take in food by eating producers or other living things. Decomposers produce nutrients for producers. Decomposers make nutrients for organisms that become food for consumers.... So the answer is [(H)]

What do organisms cluster around in the ocean floor?
Options:
- (A) kalenchoes
- (B) ferns
- (C) bacteria
- (D) Chimneys
- (E) an object
- (F) alveoli
- (G) graptolites
- (H) allow growth
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Let's think first: Organisms cluster around hydrothermal vents in the ocean floor. Chimneys top some hydrothermal vents. Organisms cluster around chimneys in the ocean floor.... So the answer is [(D)]