Genetics and Society Essay Example | Topics and Well Written Essays - 500 words

Genetics and Society - Essay Example Diploid cells which are destined to produce the male and female reproductive cells undergo a type of cell division referred to as meiosis by which the chromosomes present in the parent cell is reduced to half to form four reproductive haploid cells called gametes. This process of separation and assortment of the homologous chromosomes occurs at random and the resulting haploid cells do not contain only paternal or maternal chromosomes but a mixture of genes from both parental chromosomes. This independent assortment of genes was first observed by Mendel when he was studying the genetics of pea plants and from his study he formulated the principle of independent assortment. The process of meiosis which is responsible for the production of gametes occurs via this principle of independent assortment. Meiosis begins with the replication of a pair of chromosomes in the diploid germ cells which are destined to become male or female gametes. The replicated chromosomal pairs are called siste r chromatids which are initially joined at the central point called the centromere. As the meiotic spindle forms at each pole of the cell with the help of microtubules, the two pairs of homologous chromosomes form tetrads within which any two chromosomes can overlap or recombine to form recombinant DNA which gives rise to new genetic combinations. This process is called crossing-over. Following this the pair of chromatids are pulled towards each pole of the cell and the chromosomal pair is enclosed within a nuclei. The cell then undergoes cytokinesis during which the cytoplasm divides into two giving rise to two daughter cells each containing a haploid chromosome. Thus meiosis is an important process during which pairs of homologous chromosomes are independently assorted to give rise to haploid gametes and also the chromosomes in the tetrad stage recombine to form new combination of genes which is