Cell cycle and mitosis Flashcards
In what form does DNA exist during
interphase versus M phase/mitosis,
and what is the difference?
interphase = chromatin, loosely packed
mitosis = chromosomes, tightly packed
At what stage do the DNA molecules
duplicate?
S phase
TRUE or FALSE: The number of
chromosomes doubles during S phase.
FALSE. the number of chromosomes
stays the same (the number of
chromatids doubles).
Prophase
Chromatin condenses to chromosomes.
Centrosomes separate and begin spindle
assembly.
Prometaphase
Nuclear envelope disintegrates and
spindle fibers attach at the centrosome.
Metaphase
Chromosomes line up at the center of the cell
(“metaphase plate”).
Anaphase
Pulled by the spindle fibers, sister chromatids
detach at the centromere, and the chromosomes
migrate to opposite ends of the cell.
Telophase
Nuclear envelopes reform around
chromosomes at poles; spindles
disintegrate; chromosomes
decondense
Cytokinesis
Cytoplasm is split and cell is divided
into two.
G1
The cell is diploid and so has 16 chromosomes and each chromosome is made up of 1 chromatid.
G2
Same as G1, but sister chromatids are present
What happens when cytokinesis fails?
Binucleated or multinucleated cells
What are polytene chromosomes, and which phase of
mitosis must fail in order for them to exist?
When anaphase fails, sister chromatids remain stuck together, and
many copies of the genome remain in one cell.
What term describes the result of errors in mitosis leading
to non-identical daughter cells? (*Art Related)
Mosaicism
What is aneuploidy? Name the process that leads to this.
- Daughter cells have more or less than the expected 2n chromosomes.
- Chromosomal nondisjunction
