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
1 Like
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.
Answered By
2 Likes
Related Questions
Which of the following is not a role of decomposers in the ecosystem?
options
- Natural replenishment of soil.
- Enrichment of oxygen in atmosphere.
- Waste decomposition.
- Break-down of dead remains.
Assertion (A) : On adding dil. HCl to a test tube containing a substance ‘X’, a colourless gas is produced which gives a pop sound when a burning match stick is brought near it.
Reason (R) : In this reaction metal ‘X’ is displaced by Hydrogen.
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.
Assertion (A) : A convex mirror always forms an image behind it and the image formed is virtual.
Reason (R) : According to the sign convention, the focal length of a convex mirror is positive.
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.
Assertion (A) : If the lions are removed from a food chain it will not affect the food chain, however if the plants are removed from a food chain it will disturb the ecosystem.
Reason (R) : Plants are producers who can make food using sunlight, while lions are consumers.
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.