They decrease because the zebra mussel were taking their resources. Leaving them nothing to eat.
B is the answer I strongly believe
Natural selection<span> is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations.</span>
Answer:
1 = A
2 = B
3 = B
Explanation:
1) Black holes occur when really big stars collapse on themselves. And, in order to get big, the star has to be an old one.
2) A black hole is something huge that swallows up everything, while a protostar is just the very beginning of a star.
3) Scientist can't truly know for sure, but they can infer about them due to the effects of the surrounding areas.
Mitochondria are found in plant cells...? I'm not too sure.
