Cell division and Mitosis Flashcards
What is the name for cell division in eukaryotic cells?
Mitosis
What are the stages of the cell cycle?
Growth 1, synthesis, growth 2, mitosis
Which stages make up interphase?
Growth 1, synthesis, growth 2
What occurs during interphase?
DNA replication
What are the four stages of mitosis?
Prophase, metaphase, anaphase, telophase
What is the role of the spindle fibres in mitosis?
Attach to centromeres in the separation of chromatids
What occurs in prophase?
Nucleolus and nuclear envelope disappear, chromatin condenses into chromosomes, spindle forms.
What occurs in metaphase?
Chromosomes are lined up across the equator of the spindle
what occurs in anaphase?
Spindle fibres pull on the centromeeres until they split; spindle pulls sister chromatids to opposite poles of the spindle.
What occurs in telophase?
Spindle disintegrates, chromosomes unwind to form chromatin, nucleolus and nuclear envelope reappear
What occurs in cytokinesis?
Division of the cytoplasm occurs, producing two new cells
What happens if cell division becomes uncontrolled?
Uncontrolled cell division can lead to the formation of tumours and of cancers. Many cancer treatments are directed at controlling the rate of cell division.
What is the name for cell division in prokaryotic cells?
Binary fission
What takes place during binary fission?
- Replication of the circular DNA and of plasmids.
- Division of the cytoplasm to produce two daughter cells, each with a single copy of the circular DNA and a variable number of copies of plasmids.
How do viruses replicate?
Being non-living, viruses do not undergo cell division. Following injection of their nucleic acid, the infected host cell replicates the virus particles.
