What causes ocean water to be colder at the poles than at the equator ?

What best describes the dropping height of a ball that bounces back up to a height of 45 cm

Pls me i need this ! each cell has genes activated depending on it's job and what kind of cell it is. it is the presence of that causes the repressor protein to fall off and unblock the gene on the lac operon. if a gene is turned on then it is being an additional circular chromosome found in some bacteria that is used in genetic engineering.

At what point in the eukaryotic cell cycle does mitosis occur