Check Your Progress 1.1 1 a cell has 20 chromosomes during Gi ofinterphase, how
ID: 196778 • Letter: C
Question
Check Your Progress 1.1 1 a cell has 20 chromosomes during Gi ofinterphase, how many chromosomes would be present during prophase? 3 1.2 How many chromosomes would each of the two new cells have that resulted from the mitotic division of this cell? 1.3 The different stages of mitosis are not of equal duration; some stages are relatively long while others are quite brief. Because the frequency of cells in each stage is proportional to the relative duration of that stage, you can estimate the relative length of a stage by counting the number of cells arrested in that particular stage. Based orn the number of cells you observed in each stage of mitosis (excluding interphase), which stage do you think takes the longest time to complete? (You may want to review the slide again and count a random sample of 100 cells to answer this question.) 1.4 Which stage takes the shortest time to complete?Explanation / Answer
1.1 The interphase is the phase before actual mitosis starts. To start mitosis all the phases of interphase must be passed i.e- g1, s and g2 phases. during G1 no replication occurs. however during S phase the dna/chromosome replication occurs and (n=20 in question becomes 2n=40) and then G2 continues.
after this phase mitosis has 4 phases- prophase, metaphase, anaphase, telophase
during prophase no change in chromosome number and it remains 40.