Q: An organism's cells include organelles and a cell wall. In which taxonomic group or groups might the organism be classified?

OPTIONS:
- plants only
- bacteria or archaea
- plants, fungi, or protists
- bacteria, fungi, or protists
A: plants, fungi, or protists
Q: Some ancient Greeks tried to discover the laws of the universe through thought and logic. Which part of the scientific process were these scientists missing?

OPTIONS:
- analysis
- experiment
- conclusion
- observation
A: experiment
Q: Index fossils help scientists estimate the age of a rock because index fossil species only existed for a relatively short time. What happened to the species that are now used as index fossils?

OPTIONS:
- They became extinct.
- They changed their diets.
- They hid in marine sediments.
- They migrated to new environments.
A: They became extinct.
Q: Which force keeps the planets in their orbits around the Sun?

OPTIONS:
- gravity
- magnetism
- electricity
- friction
A:
gravity