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10 terms

MBC Chapter 11

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During what phase of the cell cycle does the DNA become replicated?
S
A parent cell divides to form two genetically identical daughter cells in the process of mitosis. For mitosis to take place _____.
the parent cell must first replicate its entire genome
In eukaryotic cells, chromosomes are composed of _____.
DNA and proteins
Which statement is correct concerning the relationship between chromosomes and genes, chromatin, or sister chromatids?
Each unreplicated chromosome consists of two sister chromatids.
Chromatin is a length of DNA in a chromosome that codes for a protein or RNA.
Genes are the DNA - protein material that make up entire chromosomes.
Each replicated chromosome consists of two sister chromatids.
Each replicated chromosome consists of two sister chromatids. Replication of a chromosome's single DNA double helix produces two identical DNA copies called sister chromatids.
Which answer correctly associates a distinctive event in mitosis with the mitotic subphase when it occurs?

Prophase: Chromosomes are replicated.
Telophase: Chromosomes condense.
Anaphase: Sister chromatids separate.
Prometaphase: Chromosomes complete their migration to the middle of the cell.
Anaphase: Sister chromatids separate.

During anaphase ("against-phase"), replicated chromosomes split into two identical sets of unreplicated chromosomes that are pulled to opposite poles of the cell.
How might spindle microtubules assist in the process of splitting centromeres?
creating tension by pulling toward opposite poles
Some cells have several nuclei per cell. How could such multinucleated cells be explained?
The cell underwent repeated mitosis, but cytokinesis did not occur.
Which answer correctly identifies a cell-cycle checkpoint with a criterion for passing it?

G2 checkpoint: Chromosomes have replicated successfully.
G1 checkpoint: Chromosomes have replicated successfully.
S checkpoint: DNA is undamaged.
Metaphase checkpoint: DNA is undamaged.
G2 checkpoint: Chromosomes have replicated successfully.

G2 occurs after S and before M phase, so it is advantageous for the cell to have a checkpoint assessing chromosome replication here.
The M-phase checkpoint is designed to make sure all chromosomes are attached to the mitotic spindle. If this fails to happen, in which stage of mitosis would the cells be most likely to arrest?
metaphase
What two types of defects does a cancerous cell possess?
Cancerous cells possess defects that make proteins required for cell growth active and tumor suppressor genes inactive.