Leon made a study chart about human-induced changes to the environment.

Environmental Changes Caused by Humans
X
Results from introducing harmful substances into the environment
Example: oil spill
Y
Results from natural areas being cleared and replaced by human development
Example: deforestation
Which headings best complete the chart?

1.X: Habitat Destruction
Y: Pollution
2.X: Long-Term Changes
Y: Short-Term Changes
3.X: Short-Term Changes
Y: Long-Term Changes
4.X: Pollution
Y: Habitat Destruction

The following image is of a diatom. it lives in water and gets food from photosynthesis. it is encased in a hard shell made of something similar to glass or sand . a diatom is a(n) because it has a) multi-celled organism; specialized parts. b) vertebrate; a skeleton. c) insect; an exoskeleton. d) single-called organism; only one cell.

Animal bodies (and even plant bodies for that matter) are complex enough that life couldn't exist without enzymes. enzymes are usually large, complex biological catalysts that are expensive to make. enzymes speed up the rate of chemical reactions without being used up during the reaction (they can be reused many times). they are highly specific in the reactions they regulate. knowing what enzymes are and how they function, why does this explain why complex life forms could not exist if there were no enzymes.

Melting glaciers is a serious threat to the environment what is the possible consequence of melting glaciers on polar bears?