A plant cell contains a large, singular vacuole that is used for storage and maintaining the shape of the cell. In contrast, animal cells have many, smaller vacuoles. Plant cells have a cell wall, as well as a cell membrane. Animal cells simply have a cell membrane, but no cell wall.
There are many theories about why living thins sleep, however, scientists are still unsure about what the answer to this question may be. Some say it is because of its restorative powers - after a good night's sleep, you feel rested, and all your brain and bodily functions work better than when you are exhausted. During sleep, some rejuvenating and growth hormones are created, which again adds to our advantage. You also relieve stress that has accumulated during the day. These are some of the reasons why we have to sleep.
Your answer would be D, desertification.
Explanation:
1) Egg cells only have half the DNA of the organism
2) in an egg cell the DNA from Mum and the DNA from that is mixed up rather than kept separate
3) egg cells are very large compared to the other cells
