Explain what you understand by sexual reproduction.

AcademicBiologyNCERTClass 7

In sexual reproduction, a gamete (such as an egg or sperm cell) with a single set of chromosomes (haploid) combines with another gamete to produce a zygote, which then develops into an organism composed of cells with two sets of chromosomes.

Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete (such as an egg or sperm cell) has a single set of chromos (diploid). The majority of multicellular eukaryotes, such as animals, fungi, and plants, go through a life cycle that is characterized by sexual reproduction. In prokaryotic organisms, sexual reproduction is not possible.

In the eukaryotic process of meiosis, which involves genetic recombination, diploid mother cells divide to create haploid cells known as gametes. The DNA sequences of the homologous chromosomes couple up and align with one another, which is followed by an exchange of genetic material between them. The result is the production of four haploid gametes, each with half the chromosomes of each parent cell but with the genetic material in the parental chromosomes recombined after two rounds of cell division.

The process of fertilization involves the union of two haploid gametes into a single diploid cell termed a zygote. Genetic material from both gametes is incorporated into the zygote. A multicellular diploid phase or generation is created after numerous cell divisions occur without the number of chromosomes changing.

Each cell in the human reproductive system has 23 pairs of 46 chromosomes. The gametes that result from meiosis in the gonads of the parents have just 23 chromosomes apiece, which are genetic recombinants of the DNA sequences found in the parental chromosomes. Each cell of the developing child will contain 23 chromosomes from each parent, for a total of 46 when the nuclei of the gametes combine to create a fertilized egg or zygote.

Updated on 10-Oct-2022 12:46:26