Evaluate the effect of crossing over on the genetic composition of an organism AND explain the effect crossing over on genetic diversity in a population.
Evaluate the effect of crossing over on the genetic composition of an organism AND explain the effect crossing over on genetic diversity in a population.
No offspring looks exactly like their parents and crossing over seems to be responsible for this. It is a phenomenon that occurs at the time of meiotic cell division. In this process, there is an exchange of genetic material between non-sister chromatids of two homologous chromosomes. This results in the rearrangement of alleles between the chromosomes which ensures the formation of new varieties. This process is also known as the recombination of genes. Crossing over occurs during the Pachytene stage of Prophase I of meiosis.
Crossing over considerably affects the genetic composition of an individual and defines the basis of meiotic division. For producing an offspring, two parental cells, each of which provides half of their genetic content to a developing gamete are needed. Suppose, if we have a parent A with genes AABBCC and parent B with genes aabbcc, then in a gamete parent A will only provide half of their genetic content as ABC. Similarly, parent B will also provide half of its genetic content i.e., abc. In gamete, every single gene can move independently of each other and produces a recombined offspring such as AABBCc which is a recombined individual. This generates differences or variabilities in the genetic composition of parents and offsprings.
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