Question

What would be the number of chromosomes in the meiocyte and gamete of onion respectively?
A. 24, 12
B. 34, 17
C. 16, 8
D. 14, 17

Answer 1

Hint: Chromosomes are thread-like structures located inside the nucleus of animal and plant cells. Each chromosome is made of protein and a single molecule of deoxyribonucleic acid (DNA). Passed from parents to offspring, DNA contains the specific instructions that make each type of living creature unique.

Complete answer: A meiocyte is a type of cell that differentiates into a gamete through the process of meiosis. Through meiosis, the diploid meiocyte divides into four genetically different haploid gametes. The control of the meiocyte through the meiotic cell cycle varies between different groups of organisms. Onion is diploid i.e., have two sets of chromosomes. A diploid cell of an onion has 16 chromosomes. Haploid gametes are produced during meiosis, which is a type of cell division that reduces the number of chromosomes in a parent diploid cell by half. When meiocyte divides to form gametes, the chromosomes become half i.e., 8. So, the number of chromosomes in a gamete of onion 8.
Hence, the correct answer is C-16, 8

Note: Chromosomes are normally visible under a light microscope only during the metaphase of cell division. Chromosomal recombination during meiosis and subsequent sexual reproduction plays a significant role in genetic diversity. The number of human chromosomes was published in 1923 by Theophilus Painter. By inspection through the microscope, he counted 24 pairs, which would mean 48 chromosomes. His error was copied by others and it was not until 1956 that the true number, 46, was determined by Indonesia-born cytogeneticist Joe Hin Tjio.