Cell division Flashcards
(14 cards)
What are the products of mitosis?
Mitosis produces two genetically identical diploid daughter cells
How do bacteria divide?
Binary fission
Explain 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
Benefits of mitosis?
Growth and repair
Stages of mitosis?
Interphase/mitosis/cytokinesis
What happens to DNA mass in mitosis?
Doubles
What happens to the number of chromosomes in mitosis?
Stays the same
What are the stages of interphase?
G1: protein synthesis
S: DNA replication (doubles set of DNA)
G2: organelle synthesis
Amount of ATP also increases
What are the 4 stages of mitosis?
Prophase
Metaphase
Anaphase
Telophase
What happens in each stage of mitosis
Prophase: Chromosomes condense become shorter and thicker. Nuclear envelope breaks down and centrioles move to opposite poles forming spindle network
Metaphase: Chromosomes line along the equator. Spindle fibres attach to chromosomes by centromeres.
Anaphase: Spindle fibres contract, pulling sister chromatids to opposite poles of the cell. Centromere divides.
Telophase: Chromosomes uncoil becoming longer and thinner. Nuclear envelope reforms= two nuclei
Spindle fibres and centrioles break down.
What happens in cytokinesis?
Division of the cytoplasm, producing two new cells.
What is cancer?
Formation of a tumour due to uncontrolled cell division (mitosis)
Treatments of cancer?
Surgery = aim is to remove tumour
Chemotherapy = - using drugs that inhibit mitosis in rapidly dividing cancer cells
- problem, also affect normal healthy cells (hair cell, skin cells, RBC) causing side effects (hair loss, dry skin, tiredness)
- treatment given as regular doses to allow time for normal healthy cells to recover in number
Radiotherapy = radiation used to destroy cancer cells
Do viruses undergo cell division?
No, they are non-living.
- Attachment protein binds to a complementary receptor protein on the surface of the host cell.
- Inject nucleic acid (DNA/RNA) into the host cell
- Infected cell replicates the virus particles.
