Question

How many pairs of chromosomes are present in human beings? Out of these, how many are sex chromosomes? How many types of sex chromosomes are found in human beings? "The sex of a newborn child is a matter of chance and none of the parents may be considered responsible for it" Draw a flowchart showing the determination of sex of a newborn to justify this statement.

Answer 1

Chromosomes are usually located inside the nucleus of plants, as well as the animals. These are thread-like structures made up of protein and single molecules of DNA. The chromosomes are passed from parents to offspring in the process of sexual reproduction.

Complete answer:
The chromosomes are the thread-like structures that are present in the nucleus of a cell. Every species has a particular set of chromosomes. In human beings, 23 pairs or 46 chromosomes are present.

From 23 pairs, 22 pairs of chromosomes or 44 chromosomes are known as autosomes. These are not sex chromosomes. They have the same shape and size. Each autosome store many genes that further have their unique functions.
The remaining one pair of chromosomes or 2 chromosomes are known as sex chromosomes, are allosomes. Allosomes are known as the sex-determining chromosomes. They are different from autosomes as in form, size, and behavior. They are also known as heterosomes.

The sex chromosomes are of two types. These are X and Y-chromosomes. The sex of a child is dependent on the probability of fusion of sex chromosomes during fertilization. Thus, the parents are not answerable for the birth of a girl child or boy child. The probability of a girl child and boy child is 50-50 percent. The chromosome of the female is XX, and the male is XY.
The flowchart representing the determination of sex is given below:

Note: The organisms reproduce asexually or sexually maintain a constant chromosome by adopting different methods.
In sexual reproduction, gametes are formed, which are haploid in nature and then unite to restore the normal diploid condition. Thus, maintaining the chromosome in number in the organism, while in asexual reproduction, the organisms divide the chromosome first and then the cells.