Valves ensure blood flows toward your heart. Vein valves work to bring the blood that flowed down via arteries back up to your heart.
Answer - C. Bodies of water would freeze from the bottom up.
Reason - Since solid water aka ICE is denser than liquid.. Then we can kiss our penguins good buy cause the whole Earth will be submerge of water since the Arctic is made of ice and if it sank boom there goes for the planet and so as Antarctica.
For number 1 the first arrow is the cell wall, the second is the membrane, and the last arrow would be the cytoplasm
For number 2 they are in distilled water Bc they are remaining the same and not shrinking up
For three draw the cells smaller salt water sucks the water out of them
For four they get smaller because the salt has a higher concentration making the water leave the cell. Once water has left the cell begins to shrink