Chapter 12: Mitosis Flashcards
What happens in the sister chromatids after mitosis?
Each of the sisters ends up in a different cell after cell division
The complex of DNA and protein that makes up a eukaryotic chromosome is properly called
chromatin
How many maternal chromosomes are present in a somatic human cell not engaged in cell division?
Human somatic cells contain a total of 46 chromosomes, half of which are maternally derived.
Chromatids are __________
identical copies of each other if they are part of the same duplicated chromosome
Each duplicated chromosome consists of two identical sister chromatids.
A biochemist measured the amount of DNA in cells growing in the laboratory and found that the quantity of DNA in the cells doubled __________.
Between these two phases of the cell cycle, the DNA is replicated during the S phase
During interphase, the genetic material of a typical eukaryotic cell is dispersed in the nucleus as long strands of __________.
chromatin
If a human somatic cell is just about to divide, it has __________ chromatids.
Down syndrome is characterized by cells having three copies of chromosome 21. As a cell in an individual with Down syndrome prepares to enter mitosis, how many chromatids would be present?
Human somatic cells have 92 chromatids just prior to cell division due to the replication of the 46 chromosomes that occurred during the S phase
94.
In telophase of mitosis, the mitotic spindle breaks down and the chromatin uncoils. This is essentially the opposite of what happens in __________.
prophase
During telophase, fragments of the nuclear envelope begin to reassemble along with portions of the endomembrane system.
Assume that you are dealing with a species in which the number of chromosomes in each somatic cell is 14. How many sister chromatids are present in the early telophase of mitosis?
- By telophase, the chromatids have separated and the individual units of DNA (now called chromosomes) are arriving at the poles. There are no chromatids at this point.
In a human skin cell that is going through the cell cycle, when do the centrosomes separate?
prophase: The centrosomes move away from each other during prophase, apparently propelled along the surface of the nucleus by the lengthening bundles of microtubules between them.
Which event or events occur during anaphase? (
A spindle made of microtubules is present during anaphase.
The centrioles are at opposite poles during anaphase.
Cohesins joining sister chromatids at the centromeres are cleaved during anaphase.
Genetically identical chromosomes (previously sister chromatids) move to opposite poles during anaphase.
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During which stage of the cell cycle do sister chromatids separate?
anaphase. Anaphase begins when the cohesins joining sister chromatids are cleaved, allowing the chromatids (now called chromosomes) to move toward opposite poles of the cell.
- does not occur in dividing bacteria. Mitosis might have had its origins in simpler bacterial mechanisms of cell reproduction. Prokaryotes (bacteria) reproduce by a type of cell division called *
Mitosis
binary fission.
When a cell in S phase is fused with a cell in G1, __________.
DNA synthesis begins immediately in the original G1 nucleus. This observation indicates that cytoplasmic signals can participate in the regulation of the cell cycle.
You would be UNLIKELY to see which of the following human cells dividing?
nerve cell
