What is the animal with unique characteristics? to be choosen from every other ones? pls ​

Atypical human cell is approximately 12.00 μm in diameter and enclosed by a membrane that is 5.000 nm thick. (a) what is the volume of the cell including the membrane? (b) what is the volume of the cell membrane? (c) what percent of the total volume does its membrane occupy? to simplify the calculations, model the cell as a sphere. enter your answers using four significant figures.

What was the land like over 500 million years ago? what was under the sea?

Acceleration is a direct result of a.) balanced forces b.) unbalanced forces c.) gravity d.) velocity