Which best describes the end result of meiosis?
A. two diploid cells identical to the parent cell
B. four haploid cells identical to the parent cell
C. two diploid cells different from the parent cell
D. four haploid cells different from the parent cell
The correct answer and explanation is:
The correct answer is: D. four haploid cells different from the parent cell.
Meiosis is a type of cell division that reduces the chromosome number by half and results in four non-identical haploid cells. It occurs in two distinct stages: meiosis I and meiosis II.
In meiosis I, homologous chromosomes (chromosomes that carry the same genes but may have different alleles) are separated. This is the reductional division, where the chromosome number is halved. In meiosis II, the sister chromatids of each chromosome are separated, which resembles mitosis but in a haploid cell.
The key result of meiosis is genetic variation. Through processes like crossing over during prophase I and independent assortment of chromosomes, genetic material is shuffled. This creates gametes (sperm or egg cells in animals) that are genetically distinct from each other and from the parent cell. The haploid cells produced contain half the chromosome number of the parent cell, ensuring that when two gametes fuse during fertilization, the resulting offspring has the correct diploid number of chromosomes.
In contrast, mitosis is a type of cell division that produces two diploid cells that are identical to the parent cell. Since meiosis involves two divisions and reduces the chromosome number, the result is not identical cells. The four haploid cells formed in meiosis have unique genetic combinations due to recombination events and the random distribution of chromosomes.
Therefore, the end result of meiosis is four genetically different haploid cells, each containing half the chromosome number of the parent cell, which is essential for sexual reproduction.