Cell Division Flashcards
What happens during interphase?
The DNA is replicated and the cell makes preparations to divide.
What are the different parts of interphase and what happens during them?
G1- The cell grows and organelles are replicated.
Synthesis- The DNA is replicated.
G2- The cell keeps growing and making proteins like tubulin which make up the spindle fibres.
What happens during mitosis?
A parent cell divides to form genetically identical daughter cells that contain the exact copy of the DNA of the parent cell.
What is mitosis needed for?
For the growth of organisms and to repair damaged tissues.
What are the steps to mitosis?
Prophase, Metaphase, Anaphase, Telophase
What happens during prophase?
The chromosomes condense and the nuclear envelope breaks down. The centrioles move to opposite poles of the cell and spindle fibres start to grow from them.
What happens during metaphase?
The chromosomes line up along the equator of the cell and the spindle fibres attach to the centromeres.
What happens during anaphase?
The centromeres divide separating the two sister chromatids of each chromosome. The spindle fibres shorten pulling the chromatids to opposite poles of the cell.
What happens during telophase?
The chromosomes uncoil and the nuclear envelope builds back up.
What happens during cytokinesis?
The cytoplasm splits into two creating two identical daughter cells.
What is cancer?
uncontrolled cell division.
What causes cancer?
A mutation in the genes that control cell division causes the cell to divide rapidly via mitosis and this creates tumours. If these tumours invade surrounding tissues it becomes cancer.
How does chemotherapy interrupt the cell cycle to kill cancer?
Chemotherapy drugs stop the production of enzymes needed for DNA replication. Without these, the cell does not go into the synthesis stage of interphase and the cell self-destructs. Radiation destroys DNA which will cause the cell to kill itself when it checks the DNA for any damage.
How do prokaryotic cells divide via binary fission?
The circular DNA and plasmids replicate. The cell gets bigger. The DNA loops move to opposite poles of the cell. The cytoplasm begins to divide and a new cell wall forms. The cytoplasm completely divides and two daughter cells are produced.
How do viruses replicate?
They inject their RNA or DNA into the host cell’s DNA. This causes that cell to make viral particles to make new viruses.
