how are the number of chromosomes and DNA content re- established in new generation during sexual reproduction
Answers
Haploid and Diploid chromosomes
The adult organisms of sexual reproduction contain two complete sets of chromosomes (Diploid). But the gametes produced by the adults during reproduction contain half the number of the chromosomes (Haploid). This occurs through a special cell division.
Fertilization
When the gametes fuse during fertilization, the resulting new generation organism gets one pair of chromosome (Haploid) from each parent and thus the chromosome becomes diploid.
Thus, the full number of chromosomes is re-established and the specific chromosome number of a species is maintained.
The germ cell that means the sperm in males and ova in females constitutes that they are haploid in number that means that they have n number of chromosome in them. After fertilization they have 2n number of chromosome in them : one set comes from the ova and another from the sperm. Fertilisation is the fusion of male and female gamete in the reproductive tract of the female organism which results in a newborn.