In: Biology
In an organism with 52 chromosomes, how many bivalents would be expected to form during meiosis?
Ans.
In any organisms which are sexually produced half of the chromosomes comes from maternal side and half of the chromosomes comes from the paternal side paired with the homologous chromosomes at the time of crossing over in meiosis I.
Before the completion of meiosis I there are S phage in which chromosomal DNA are replicated and forms sister chromatids in each chromosome termed as bivalent chromosome when it is paired with homologous chromosome.
After crossing over these bivalent chromosomes are moves towards opposite pole and forms daughter cell with half of the chromosome.
meiosis II same as mitosis which same daughter cells as parental cell.
Hence in this question as we have mentioned.. In meiosis I DNA content is doubled due to replication and when it paired with homologous chromosomes forms bivalent stage. Hence If any organism has 52 chromosome then there will be 26 bivalent at the time of meiosis I.