Here are the answers to your questions:
**Question 1 A)** Osmosis is defined as:
- **The movement of water across a semipermeable membrane down a concentration gradient from high to low, using no energy.** (Correct Answer)
**Question 2 A)** Active transport is defined as:
- **The movement of molecules up a concentration gradient from low to high, using energy.** (Correct Answer)
**Question 3 A)** An environment is considered isotonic when:
- **The concentration of solute in the environment and the concentration inside the cell are at equilibrium.** (Correct Answer)
**Question 4 A)** Cells dispose of large waste molecules through a process called:
- **Exocytosis.** (Correct Answer)
**Question 5 A)** If a cell is dropped into a saltwater solution and shrivels up, it can be inferred that the type of saltwater solution is:
- **Hypertonic.** (Correct Answer)