Question

Identify the event in meiosis mediated by the enzyme recombinase.

• A. Synaptic pairing
• B. Terminalization
• C. Crossing Over
• D. Interkinesis

Answer 1

The Correct Option is C

Recombinase is a group of enzymes, such as RecA in prokaryotes and Rad51/Dmc1 in eukaryotes, that facilitate genetic recombination. During meiosis, recombinase plays a crucial role in crossing over, which occurs in the pachytene stage of prophase I. This process involves the exchange of genetic material between non-sister chromatids of homologous chromosomes. Recombinase ensures proper alignment, strand invasion, and recombination of DNA segments.

Meiosis is a type of cell division that occurs in gametes (sperm and egg cells in animals, and pollen and ovules in plants). It reduces the chromosome number by half, resulting in four genetically unique daughter cells, each with half the number of chromosomes as the parent cell. This process is essential for sexual reproduction, ensuring genetic diversity and maintaining the stability of the organism's chromosome number across generations.

Thus, the correct answer is (C) Crossing Over, as it is the only event directly mediated by recombinase.

Answer 2

During meiosis, the enzyme recombinase, including proteins like Rad51 and DMC1 in eukaryotes, plays a pivotal role in the process of crossing over. This event occurs during prophase I, where homologous chromosomes exchange genetic material, enhancing genetic diversity. Recombinase facilitates the alignment and strand exchange between homologous DNA segments, leading to the formation of chiasmata. This process is critical for proper chromosome segregation and the generation of genetically unique gametes. Synaptic pairing and terminalization, while related to meiosis, are not directly driven by recombinase activity.

Thus, the correct answer is (C) Crossing Over.