Crossing over between homologous chromosomes occurs during which sub-stage of Prophase I in meiosis?
A. Leptotene
B. Zygotene
C. Pachytene
D. Diplotene
Answer: Option C
Solution (By JKExamLibrary)
Prophase I of meiosis is divided into five sub-stages: leptotene, zygotene, pachytene, diplotene, and diakinesis. Crossing over, the exchange of genetic material between non-sister chromatids of homologous chromosomes, occurs specifically during the pachytene stage at structures called recombination nodules.
Explanation:
Vitamin K is required for the gamma-carboxylation of clotting factors II, VII, IX, and X, including prothrombin. Deficiency leads to prolonged clotting time and hemorrhagic disorders.
Explanation:
Gastrin is a hormone secreted by G cells in the stomach antrum, stimulating parietal cells to secrete HCl and promoting gastric motility. It is released in response to food in the stomach.
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