<span>Species is a group of reproducing populations that are isolated from other groups. </span>
Answer:
Transcription factors
Explanation:
They are part of the cell's core transcription toolkit, needed for the transcription of any gene. RNA polymerase binds to a promoter with help from a set of proteins called general transcription factors.
Answer: the capillaries.
<span>The blood capillaries are blood vessels with very small caliber. They form the blood distribution and collection network in cells. They are the communication between branches
originating from the arteries and with the smaller
veins. It is on the walls of the capillaries that occurs <span>the exchange of water, oxygen, CO2,
other nutrients and chemical residues.</span></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.