Mitosis Flashcards
What happens during prophase?
centrioles duplicate and migrate to opposite poles and chromosomes condense
What happens during prometaphase?
the chromosomes are clearly double structures with visible sister chromatids (which are kept in close proximity of each other by the Cohesin complex, a multisubunit protein complex), centrioles have reached the opposite poles and the spindle fibres have formed;
What happens during metaphase?
all centromeres align at the equatorial plane to form the metaphase plate. Microtubules of the spindle fibres associate with the centromere, which in turn associates with a complex protein structure known as the kinetochore. The kinetochore mediates the movement of the chromosomes towards the poles.
What happens during anaphase?
separation of the sister chromatids following splitting of the centromere –known as disjunction- takes place, the daughter chromosomes then migrate to opposite poles
What happens during telophase?
a nuclear membrane will form around the chromosomes and division of the cytoplasm –cytokinesis- takes place
Chromosomes are divided at anaphase to form…
daughter chromosomes
Kinetochores are present in each chromosome at the…
centromere
What must this cell do before it can carry out mitosis? (The cell has a diploid number of chromosomes 2n=4)
Replicate DNA and duplicate the centrosome
Assume that the G1 nuclear DNA content of a species is 30 picograms. What would be the expected DNA content in a somatic cell going through metaphase?
In metaphase the chromosomes have already replicated and ready to be split at the centromere, but the cell has not yet divided and therefore contains double the amount of the DNA, i.e., 60 picograms.
How many chromatids will you see at the end of mitotic prophase in the cell of an organism with a diploid number of 14?
When chromosomes arranged at the metaphase plate, each one of them has at that point two sister chromatids joined at the centromere. Therefore, the total number of chromatids will be 28.
How many chromosomes will be migrating to opposite poles during mitotic anaphase in the cell with diploid number 14?
Once the chromatids split and begin migrating, they “become” chromosomes again, therefore 28 chromosomes in total will be migrating to opposite poles and 14 will end up in each pole, keeping the diploid number of the parental cell the same.
