Meiosis is the process of development of gamates in sexually reproducing organisms. Both males and females use meiosis to produce their gametes. In females the process of meiosis is called oogenesis as it produces oocytes which further develops into ova (eggs) and in males spermatogenesis takes place to produce sperms. Meiosis takes place in the germ cells of the organism. Meiosis is also known as reduction division as a diploid cell reduce to develop 4 haploid daughter cells. Prophase I is the initial phase of meiosis. This phase has six substages, therefore it requires more time to complete especially in oogenesis. During prophase I homologous chromosomes pair exchange their DNA this process results in chromosomal crossover. The new combination of DNA in the cross over chromosomes will be a source for genetic variations with production of new combination of allele. In metaphase I homologous pair of chromosome move together along a metaphase plate , microtubules emerge from the spindle and attach at the kinetochores near the centromere of each chromosomes. Microtubule from one side of the spindle attach to one of the chromosome in the homologous pair and that of other side attaches with other chromosome of each pair. Because of microtubules chromosome pair align at the metaphase plate (equator of the cell). The random alignment of chromosome pair at the equator plate will result in different proportion of transfer of genes from maternal and paternal chromosomes. This is the law of independent assortment, hence this will result in genetic diversity in the daughter cells.
photosynthesis removes carbon dioxide from the atmosphere, and cellular respiration puts it back. Photosynthesis releases oxygen into the atmosphere, and cellular respiration uses that oxygen to release energy from food
