The second layer of the Earth’s atmosphere, stratosphere.
The answer is due to the increase of myelin. Hope this helps you.
Answer: No there is not im pretty sure there are only those two cell types.
Explanation:
<h2><u>Answer:</u></h2>
The correct option is B (The longer-spined sea urchins existed before the shorter-spined sea urchins.)
<h3><u>Explanation:</u></h3>
The more drawn out spined ocean urchins existed before the shorter-spined ocean urchins.
Since the shorter spined urchins are higher up, that demonstrates that they developed from the more drawn out spined urchins, implying that having the shorter spines was useful to them as an animal types, so the shorter spines came AFTER the more extended spines.