Cell division Flashcards
When are daughter cells not identical to the parent cell in mitosis?
In the rare event of mutation
What period precedes mitosis?
Interphase
What happens during interphase?
The cell carries out normal functions and the DNA is unravelled and replicated, the organelles grow
What’s the function of the centromere?
Joins together the two copies of DNA after replication
What are the stages of mitosis?
Prophase, metaphase, anaphase and telophase/cytokinesis
What happens to the chromosomes during prophase?
Become visible, initially as long thin threads, they are drawn to the equator of the cell by the spindle fibres attached to the centromere
What are centrioles?
Two cylindrical organelles in animal cells, that move to the poles of the cell
What do the centrioles do during prophase?
Spindle fibres develop and span the cell from poles, collectively this is called the spindle apparatus
What happens to the nucleus during prophase?
Nucleolus disappears and nuclear envelope break down, leaving the chromosomes free in the cytoplasm
When are chromosomes made to be seen as two chromatids?
Metaphase
What happens during metaphase?
The chromosomes are pulled across the spindle apparatus towards the equator of the cell
What happens during anaphase?
Centromeres divide into two and the spindle fibres pull the individual chromatids to poles where they are now considered chromosomes
Where is the energy for anaphase provided from?
Mitochondria
What happens if cells are treated with chemicals that destroy the spindle fibres?
The chromosomes remain at the equator, unable to reach the poles
What happens to the chromosomes during telophase?
The chromosomes reach their respective poles and become longer and thinner, finally disappearing altogether, leaving widely spread chromatin
