If an organism’s haploid number is 12, its diploid number is A. 12. B. 6. C. 24. D. 3.
The correct answer and explanation is:
Correct Answer: C. 24
To understand this, it’s important to know the difference between haploid and diploid numbers. The haploid number (symbolized as n) refers to the number of chromosomes in a gamete, which is a reproductive cell like a sperm or an egg. These cells contain only one set of chromosomes, meaning one chromosome from each pair.
In contrast, the diploid number (symbolized as 2n) refers to the number of chromosomes in a body cell or somatic cell, which contains two sets of chromosomes—one from the mother and one from the father.
If the haploid number of an organism is 12, that means its gametes carry 12 chromosomes. When two gametes fuse during fertilization, their chromosome numbers combine. So:
Haploid number (n) = 12
Diploid number (2n) = 2 × 12 = 24
This means the resulting zygote will have 24 chromosomes, and every somatic cell of the organism will also have 24 chromosomes.
For example, in humans, the haploid number is 23, and the diploid number is 46. This same principle applies to other organisms, whether the numbers are larger or smaller.
Each species has its own characteristic number of chromosomes. The relationship between haploid and diploid numbers remains the same: the diploid number is always twice the haploid number.
Therefore, if an organism’s haploid number is 12, the correct diploid number is 24, making option C the right choice. Options A (12), B (6), and D (3) do not follow the biological principle of how chromosome numbers relate in sexual reproduction.