Which statement about enzymes is correct? a an enzyme decreases the rate of a chemical reaction. b an enzyme is shaped to interact with specific molecules. c an enzyme increases the activation energy of a chemical reaction. d an enzyme is broken down during a reaction and has to be replaced.

Which best compares habitat and niche? o niche is a place in which organisms live, and habitat is the way in which an organism fits into its habitat. o habitat is a place in which organisms live, and niche is the way in which an organism fits into its habitat. habitat is a group of organisms that live in an area, and niche is a specific species that lives in that areao niche is a group of organisms that live in an area, and habitat is a specific species that lives in that area.

The table shows dates and appearance of index fossils. which rock layers can be dated most precisely? a) a layer containing both a fossil 4 and a fossil 3 b) a layer containing both a fossil 2 and a fossil 3 c) a layer containing both a fossil 1 and a fossil 4 d) a layer containing both a fossil 1 and a fossil 2

How water is moving through the ecosystem ?