Complete the statements below.
When muscles contract, they become
The muscles of the rear end, legs, and feet are called muscles.
muscles move food down the
digestive tract.

1)  Shorter and thicker

2) Anti-gravity muscles

3) Smooth muscles

For anyone on part 2:

4) contract and produce heat

For anyone on part 3:

5) blood and oxygen

"do a testcross with a homozygous recessive plant."

allowed for the prediction of the properties of missing elements.