Science
Assertion (A) : Generally, the number of chromosomes in a cell and in a germ cell is not the same in species.
Reason (R) : When two germ cells combine, they restore the normal number of chromosomes in a species.
options
- Both A and R are true, and R is the correct explanation of A.
- Both A and R are true, and R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Genetics
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Answer
Both A and R are true, and R is the correct explanation of A.
Reason —
Assertion (A) is true because in most species, the number of chromosomes in somatic cells (body cells) and germ cells (sex cells) is not the same. Somatic cells are diploid (2n), meaning they have pairs of chromosomes, while germ cells are haploid (n), containing only one chromosome from each pair. This difference results from meiosis, where the chromosome number is halved to ensure stability of chromosome count across generations.
Reason (R) is also true because when two germ cells (a sperm and an egg) combine during fertilization, the normal diploid number of chromosomes is restored in the zygote which maintains the species’ chromosome number from one generation to the next.
Hence, both A and R are true, and R is the correct explanation of A.
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