Question

1. we want to see whether soil from a volcano has more or less nutrients than soil from other inhospitable environments.

a. independent variable:
b. dependent variable:

1. we want to see if different types of cat have different metabolic rates, resulting in a weight difference.

a. independent variable:
b. dependent variable:

Explanation:

In an experiment, the independent variable is what is changed or controlled, and the dependent variable is what is measured and affected by the independent variable. For the soil - nutrients experiment, the source of soil (volcano or other inhospitable environments) is manipulated, and the amount of nutrients is measured. For the cat - metabolism experiment, the type of cat is manipulated, and the weight (affected by metabolic rate) is measured.

Answer:

5a. Source of the soil (volcano or other inhospitable environments)
5b. Amount of nutrients in the soil
6a. Type of cat
6b. Weight of the cat