3.2 Cells - cell cycle and mitosis Flashcards
how do eukaryotic cells divide?
divide by mitosis or meiosis
how do prokaryotic cells divide?
prokaryotic cells replicate by binary fission
do viruses undergo cell division?
viruses do not undergo cell division as they are non-living
what is the process of binary fission?
binary fission involves the circular DNA and plasmids (if present) replicating
then the cytoplasm splitting to create two daughter cells
each daughter cell has one copy of the circular DNA, but a variable number of plasmid copies
where does viral replication occur?
inside the host cells and involves the injection of nucleic acid into the cell
what are the three main stages of the cell cycle?
interphase (G1, S, G2)
nuclear division (mitosis or meiosis)
cytokinesis
what happens during interphase?
the longest stage in the cell cycle
interphase is when the organelles duplicate, the cell grows and then DNA replicates
what does mitosis create?
creating two identical diploid cells
mitosis creates cells with identical DNA for growth and repair
what does meiosis create?
creating four genetically different haploid cells
meiosis creates gametes
what is cytokinesis?
the division of the cytoplasm to create new daughter cells
what are the 4 key stages of mitosis?
Prophase
Metaphase
Anaphase
Telophase
what happens during prophase of mitosis?
chromatin condenses into chromosomes and the nucleolus disappears
what happens during metaphase of mitosis?
chromosomes line up along the metaphase plate (imaginary plate)
what happens during anaphase of mitosis?
chromosomes break at centromeres, and sister chromatids move to opposite ends of the cell
what happens during telophase of mitosis and cytokinesis?
the chromosomes are now at each pole of the cell and become
longer and thinner again
The spindle fibers disintegrate, and the nucleus starts to reform.
The final stage in the cell cycle is when the cytoplasm splits in two to create the two new genetically identical cells
