Which of the following events is unique to meiosis?
A. Formation of a spindle apparatus B. Chromosomal condensation C. Genetic recombination D. Separation of sister chromatids
The Correct Answer and Explanation is :
The correct answer is C. Genetic recombination.
Explanation:
Meiosis is a specialized form of cell division that occurs in sexually reproducing organisms, leading to the formation of gametes—sperm and eggs. One of the defining features of meiosis is genetic recombination, which occurs during prophase I of meiosis I. This process involves homologous chromosomes pairing up and exchanging segments of genetic material through a mechanism called crossing over.
This exchange of genetic material results in new combinations of alleles on each chromosome, contributing to genetic diversity in the offspring. The significance of genetic recombination cannot be overstated; it plays a critical role in evolution by creating variations that can be acted upon by natural selection. This diversity is essential for populations to adapt to changing environments and helps reduce the likelihood of genetic diseases caused by recessive alleles.
The other events listed—formation of a spindle apparatus, chromosomal condensation, and separation of sister chromatids—are not unique to meiosis and also occur in mitosis:
- A. Formation of a spindle apparatus: This structure forms during both meiosis and mitosis, facilitating the separation of chromosomes.
- B. Chromosomal condensation: Chromosomes condense into visible structures during both meiosis and mitosis, allowing for their proper segregation.
- D. Separation of sister chromatids: This occurs in both meiosis II and mitosis, where sister chromatids are pulled apart to opposite poles of the cell.
In summary, while meiosis shares several common processes with mitosis, genetic recombination stands out as a unique event critical for fostering genetic diversity, which is essential for the evolutionary adaptability of species.