3.7 Mitosis Flashcards
What is mitosis?
A part of the cell cycle in which a eukaryotic cell divides to produce two daughter cells, each with the identical copies of DNA produced by the parent cell during DNA replication.
What are the 4 stages of mitosis?
- prophase
- metaphase
- anaphase
- telophase
What happens during interphase?
- cell synthesises protein
- DNA replicates
- cell growth
What happens to the chromosomes during interphase?
They are invisible
What happens during prophase?
- nuclear envelope disintegrates (分解)
- nucleolus disappears
- centrioles move to opposite ends
- spindle fibres start to develop
What happens to the chromosomes during prophase?
They become visible
What happens during metaphase?
Spindle fibres form and start to attach to the centromere of each chromosome.
What happens to the chromosomes during metaphase?
They line up on the centre of cell.
What happens during anaphase?
Spindle fibres attach to the centromere of each chromosome and are shortened to pull individual chromatids to opposite poles of the cell.
What happens to the chromosomes during anaphase?
They are broken down into chromatids as the spindle fibre pull them.
What happens during telophase?
- nuclear envelope and nucleolus reform
- spindle fibres disintegrate (分解)
What happens to the chromatids during telophase?
They reach the pole and become indistinct (模糊) .
What are chromatids?
One of the two strands of a chromosome that are joined together by centromere before cell division.
How do cells divide in prokaryotic cells?
Binary fission
What does binary fission involve?
- replication of the circular DNA and plasmids
- growing of cell
- 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)
- forming a new cell wall
