Gravity , Explosion
<u>Explanation:</u>
Nebulae are made of dust and gases—mostly hydrogen and helium. The dust and gases in a nebula are very spread out, but gravity can slowly begin to pull together clumps of dust and gas. As these clumps get bigger and bigger, their gravity gets stronger and stronger.
Eventually, the clump of dust and gas gets so big that it collapses from its own gravity. The collapse causes the material at the center of the cloud to heat up-and this hot core is the beginning of a star.
Answer:
The correct answer is A.
Explanation:
A mutagen changes the level of mutations that occur in the DNA either by affecting it physically or chemically. This helps researchers create different organisms with altered phenotypes according to what the research needs so that the genes can be investigated further under a controlled environment.
So the answer is A.
I hope this helps.
3. any trait that confers even a small increase in the probability that its possessor will survive and reproduce will be strongly favored and will spread through the population.
Explanation:
- Natural selection is a nonrandom process by which biological traits become more or less common in a population as a function of the differential reproduction of their bearers of differences in the rate of survival.
- Natural selection can act on any heritable phenotypic trait and operate among any entities that reproduce, show inheritance of their characteristics from one generation to the next, and vary in fitness.
- Natural selection is the machine that drives evolution. It also explains adaptation.
