How does meiosis brings about genetic variation?

Meiosis creates sex cells called gametes. Gametes are genetically unidentical and only carry half of the DNA of the original organism. Gametes are used for sexual reproduction, when a new organism is produced to gametes fuse together for a complete set of DNA. Meiosis forms four genetically unidentical sperm cells in males and one genetically unidentical ova with three polar bodies in females. Because the cells produced by meiosis are all genetically unidentical each organism that develops from a fertilized egg will be unique and exhibit genetic variation.

The open ocean begins at the low-tide mark and extends to the end of the continental shelf

above statement is not a true statement about the open ocean because the open ocean has low levels of nutrients. most of the photosynthetic activity on earth occurs in the open ocean within the photic zone. organisms in the deep ocean are exposed to frigid temperatures and total darkness but it does not begin at the low-tide mark.