Q: What organ systems link exchange surfaces with cells throughout the body? Choices: - vascular - pulmonary - nervous - circulatory A:
circulatory

Q: In what do a roundworm's eggs pass from host to the environment? Choices: - skin - arms - mouth - feces A:
feces

Q: Q: What type of disturbance do even dominant plants depend on in many biomes? Choices: - mass extinction - radiation - seismic force - periodic A:
A: periodic

Question: Q: Burning gas to run our cars is an example of how human activity is contributing to what global event? Choices: - ozone change - carbon change - metamorphic change - climate change A:
Answer: climate change

*Question*
Q: The geologic time scale is divided into eons, eras, periods, and? Choices: - cultures - tropics - zones - epochs A:
**Answer**
epochs

Q: Mineral crystals that form when magma cools are usually _______ than crystals that form when lava cools. Choices: - older - denser - smaller - larger A:
larger