Meiosis contributes to genetic recombination via independent assortment of homologous chromosomes and crossing-over events. Genetic recombination is vital for the existence of genetic variability within a species.
Meiosis is cell division specific to sex cells and involves more than the simple copying of genetic material that occurs during mitosis. Most of the cells in the human body contain 46 chromosomes, half from the mother and half from the father. These are diploid cells. The goal of meiosis is to create reproductive haploid cells, which are cells with only 23 chromosomes. This is necessary so that, after fertilization, an offspring's cells contain the appropriate chromosome number. Meiosis also provides for the random alignment and recombination of genetic material that ensures a person is never a copy of one parent or the other.
Chromosomes exist in pairs as homologous chromosomes. One chromosome from each pair comes from the maternal parent, the other from the paternal parent. During meiosis homologous chromosomes separate independently. Independent assortment means that there is no mechanism by which these chromosomes associate with one another. Because of this, the sex cells that are the end product of meiosis may contain any combination of maternal and paternal chromosomes.
Sometimes, when homologous chromosomes are paired, each may lose a small portion that then reconnects to the other member of the pair. This is crossing over. When crossing over occurs, homologous chromosomes trade genetic material with one another.Learn More
Bacterial transduction is the process by which a bacterium's genetic material is transferred to a second bacterium through a viral medium. The types of viruses that can carry out this process are called bacteriophages, which preferentially infect bacteria and use them to produce virus progeny.Full Answer >
Meiosis leads to increased genetic variation by reshuffling genes and creating random genes. The variation produced by meiosis accounts for differences in closely related individuals, such as members of the same family, as well as genetic differences in people within larger populations. Some genetic differences appear in small deviations, such as slightly different shapes of noses and eyebrows, while others account for variations in skin color and body shape.Full Answer >
Genetic variation is important to evolution because it helps to maintain the health of a population by constituting alleles that may be useful in overcoming stresses such as diseases and pests. Without genetic variation, some of the fundamental mechanisms of evolutionary changes would not operate.Full Answer >
There are three types of human genetic engineering: somatic, germline and cloning. Somatic engineering adds genes to body cells. Germline engineering adds genes to human eggs, embryos or sperm, and cloning creates a copy of an organism.Full Answer >