For a certain animal cell n 23 For this animal how many chr

For a certain animal cell, n = 23. For this animal, how many chromatids are in a somatic cell in G_1? Human brain cells do not divide, so what specific part of the cell cycle are they arrested in? A drug that disrupts tubulin polymerization is applied to some cells. What specific part of the cell cycle will be disrupted? Examine the cell at the right in metaphase I How many chromatids? What is n (haploid chromosome number) for this organism? When a baby girl is born, her oocytes have begun meiosis but are paused at the end of Prophase I. At puberty hormones trigger meiosis to proceed for a few oocytes in each month. At the same time the hormones trigger mitosis for the surrounding follicle cells that support the oocyte. How many chromosomes are present in the developing oocytes of a baby girl?

Solution

1 . A . The chromosome has a single chromatid before the replication of dna in S phase

So For somatic cells where n =23 , 2n=46 . Each cell at g1 phase has 46 chromosomes and 46 chromatids (2n)

B. Brain cells do not divide , they get arrested at g1 phase . The replication occurs at S phase. Brain cells do Not undergo S phase. They are arrested at g1 phase or enter into G_o phase.