A substrate binds to an enzyme's active site true or false

True

Explanation:

It's true that a substrate binds to an enzyme's active site because of  non-covalent interactions like the H-bond, ionic interactions, and hydrophobic bonds.

the second type of galaxy is called a barred spiral, which has a thing called a bar straddling the nucleus

c) 50% there are four chromosomes. after crossing over, 2 of the four have been changed. that means any gamete has a 2 in 4 chance or 50% chance of receiving the mutated chromosome.