Question

Briefly explain the role of chromosomes in heredity and its importance.

Answer 1

Chromosomes:

• These are the vehicles which play a vital role in heredity by passing the traits from parents to offspring.
• These are the thread-like structures which are composed of DNA and proteins.
• These are found in the nucleus of cells.
• Typically, humans have 46 chromosomes which are organized into 23 pairs with one set inherited from each parent.
• Each of the chromosome contains numerous genes, that are segments of DNA which encode specific instructions for the development and functioning of an organism.
• Genes are the units of heredity which are responsible for passing on traits or characters such as eye color, hair texture, and susceptibility to certain diseases.
• During the process of sexual reproduction, the chromosomes undergo a crucial event called Meiosis.
• Meiosis - this is a specialized form of cell division which occurs in reproductive cells i.e., sperm and eggs and results in the production of gametes i.e., sex cells with half the number of chromosomes that are found in other cells.
• This reduction in chromosome number plays a vital role to ensure the proper number of chromosomes which is restored during fertilization.
• During fertilization, when an egg and a sperm cell unite, each contributes half of the required chromosomes which results in a full complement of chromosomes in the offspring.
• The combination of this genetic material from both the parents creates a unique genetic makeup for each individual.
• The interaction and arrangement of genes on chromosomes determine how traits or characters are inherited.
• The phenomenon of tendency of genes located on the same chromosome to inherit together is known as genetic linkage.
• The genes can also undergo recombination during meiosis where the portions of the genetic material are exchanged between the chromosomes.
• This recombination contributes to the genetic diversity and the generation of new combinations of traits or characters in the offspring.
• The changes in the DNA sequence known as mutations also occur in chromosomes.
• These alterations or changes may be inherited and can lead to variations in the traits or the development of genetic disorders.

Chromosomes:

• These are the carriers of genes and they serve as the vehicles for passing genetic information from parents to offspring.
• These are known as the Physical basis of heredity.