Q: Fact 1: Most invertebrates have a more complex nervous system. Fact 2: Invertebrates are animals without a backbone. Given the two facts above, animals that tend to have complex nervous systems are missing what?

OPTIONS:
- Energy
- Energy.
- nervous system
- Chlorophyll
- backbone
- alleles
- abdomen
- brain

A: backbone

Q: Fact 1: Endocrine hormones travel throughout the body in the blood. Fact 2: Puberty leads to hormonal and sexual changes. Given the two facts above, puberty leads to sexual changes that travel throughout the body in what?

OPTIONS:
- blood
- A drug.
- hair
- sleep
- painful
- years
- eyes
- chest

A: blood

Q: Fact 1: Threatening behavior causes a fight-or-flight response in animals. Fact 2: Adrenaline is for emergency use only in a fight and flight situation. Given the two facts above, what is adrenaline a response to?

OPTIONS:
- earthquakes
- water
- magnetism
- threats
- Heart rate
- hormones
- threatened
- heat

A: threats

Q: Fact 1: Creating paper requires cutting down trees. Fact 2: Trees only grow to be cut down. Given the two facts above, what needs to grow for paper to be made?

OPTIONS:
- paper
- books
- trees
- birds
- grass
- flowers
- fibers
- plants

A:
trees