Legumes, with the proper soil bacteria, convert nitrogen gas from the air to a plant available form. Therefore, they do not need nitrogen fertilization, and can even add nitrogen to the soil. "Much of the nitrogen benefit of legumes comes from the plant residue - shoots and roots
During meiosis, chromosome pairs are split apart and distributed into cells called gametes. Each gamete contains a single copy of every chromosome, and each chromosome contains one allele for every gene. Therefore, each allele for a given gene is packaged into a separate gamete.
Apoptosis is important for programmed cell destruction when a cell begins to grow abnormally, or when cells become inefficient at completing the cell cycle and providing the specific set of functions to the organism. (cancer/abnormal cells, and old cells)
