is situated opposite to origin of replication site . . Significance of DNA It is responsible for the transmission of hereditary information from one generation to next generation. Figure .
Replication of DNA DNA polymerase Original DNA Okazaki fragment RNA primer Primase Helicase Topoisomerase Parent DNA Genetics It contains information required for the formation of proteins. It controls the developmental process and life activities of an organism. . Sex Determination The formation of zygote into male or female sex during development is called sex determination.
Sex is determined by the chromosomes of an individual. . . Sex Determination in Human Recall that human beings have pairs of chromosomes out of which pairs are autosomes and one pair ( rd pair) is the sex chromosome.
The female gametes or the eggs formed are similar in their chromosome type ( +XX). Therefore, human females are homogametic . The male gametes or sperms produced are of two types. They are produced in equal proportions.
The sperm bearing ( +X) chromosomes and the sperm bearing ( +Y) chromosomes. The human males are called heterogametic. Figure . Sex determination in human Female Male It is a chance of probability as to which category of sperm fuses with the egg.
If the egg (X) is fused by the X-bearing sperm an XX individual (female) is produced. If the egg (X) is fused by the Y-bearing sperm an XY individual (male) is produced. The sperm, produced by the father, determines the sex of the child. The mother is not responsible in determining the sex of the child.
Now let’s see how the chromosomes take part in this formation. Fertilization of the egg ( +X) with a sperm ( +X) will produce a female child ( +XX). while fertilization of the egg ( +X) with a sperm ( +Y) will give rise to a male child ( +XY). .
. Mutation The term mutation was introduced by Hugo De Vries in when he observed phenotypic changes in the evening primrose plant, Oenothera lamarckiana . Mutation is an inheritable sudden change in the genetic material (DNA) of an