Answer: A
Explanation:
Our universe was born from the Big Bang about 13.5 billion years ago. ... Our solar system began forming about 4.6 billion years ago within a concentration of interstellar dust and hydrogen gas called a molecular cloud. The cloud contracted under its own gravity and our proto-Sun formed in the hot dense center.
Answer:
B. Not all nonvascular plant bear seeds, but all vascular plants do bear seeds.
Explanation:
Answer:
D
Explanation:
Hormones are bigger than the cell pores hence cannot pass through the cell membrane to influence biochemical processes. Therefore, hormones (such as glucagon and insulin) bind onto receptors on the cell membrane, then transmembrane proteins, such as the G-protein, change conformation activating the secondary messengers inside of the cell. Cyclic- AMP is a major secondary messenger significant in activating protein kinases.
Answer:
Atp
Explanation:
This is the correct answer
Louder cause it makes more sound
