The number of chromosomes in parents and offspring of a particular species remains constant due to-
The number of chromosomes in parents and offspring of a particular species remains constant due to-
The correct option is B Halving of chromosomes during gamete formation.
The correct option is B.
Explanation for correct option-
- An adult organism has a diploid chromosomal state. In sexual reproduction, the haploid male and female gametes fuse to form a diploid zygote, which later develops into a new individual.
- The gametes are haploid because the process of gamete formation involves meiotic divisions, which reduces the chromosome number by half. This ensures that the number of chromosomes in both parents and offspring remains constant.
Explanation for incorrect options-
Option A:
A zygote formed after the fusion of haploid gametes is diploid. The doubling of chromosomes after zygote formation will lead to a tetraploid state, which is not the state of chromosomes in parents.
Option C:
The doubling of chromosomes after gamete formation will give rise to diploid gametes, whose fusion will give rise to a tetraploid individual. This will not ensure consistency in the number of chromosomes in two generations.
Option D:
The gametes naturally formed are in haploid condition (n). Halving the number of chromosomes after gamete formation will result in further deduction of chromosome (n/2), and the fusion of these gametes (n/2) will give rise to a haploid (n) zygote. This is not the chromosomal state of the parent individual.
Final answer: The number of chromosomes in parents and offspring species remains constant because the number of chromosomes gets halved during gamete formation.
Halving of chromosomes during gamete formation.
The correct option is B.
Explanation for correct option-
- An adult organism has a diploid chromosomal state. In sexual reproduction, the haploid male and female gametes fuse to form a diploid zygote, which later develops into a new individual.
- The gametes are haploid because the process of gamete formation involves meiotic divisions, which reduces the chromosome number by half. This ensures that the number of chromosomes in both parents and offspring remains constant.
Explanation for incorrect options-
Option A:
A zygote formed after the fusion of haploid gametes is diploid. The doubling of chromosomes after zygote formation will lead to a tetraploid state, which is not the state of chromosomes in parents.
Option C:
The doubling of chromosomes after gamete formation will give rise to diploid gametes, whose fusion will give rise to a tetraploid individual. This will not ensure consistency in the number of chromosomes in two generations.
Option D:
The gametes naturally formed are in haploid condition (n). Halving the number of chromosomes after gamete formation will result in further deduction of chromosome (n/2), and the fusion of these gametes (n/2) will give rise to a haploid (n) zygote. This is not the chromosomal state of the parent individual.
Final answer: The number of chromosomes in parents and offspring species remains constant because the number of chromosomes gets halved during gamete formation.
