1.6 - Cell division Flashcards
What is mitosis?
division of the nucleus into 2 genetically identical nuclei
Why is mitosis used? (GATE)
G: Growth
A: Asexual reproduction
T: Tissue repair
E: Embryonic development
What are the stages of mitosis?
- interface
- prophase
- metaphase
- anaphase
- telophase
*6. Cytokinesis
What is interface?
G1 / G2: increase volume of cytoplasm, organelles produces, proteins synthesized
synthesis: DNA replicated
What is prophase?
- DNA supercoils
- nuclear membrane broken down
- centrosomes move to opposite poles of the cell
- spindle fibres begin to form
What is metaphase?
- chromatids line up in center of cell
- spindle fibres (microtubules) attach to the centromere of sister chromatids
What is anaphase?
- contraction of spindle fibres –> separation of sister chromatids
- chromatids –> chromosomes
- chromosomes move to opposite poles of cell
What is telophase?
- chromosomes uncoil
- spindle fibres disappear
- nuclear membrane reforms
What is cytokinesis?
the splitting of cell immediately following mitosis
Cytokinesis in animal cells
clevage furrow forms around the middle and pinches the cell in two
Cytokinesis in plant cells
cell plate forms in the middle and grows until cell separates
What are cyclins?
proteins that control the progression of cells through the cell cycle. marks the checkpoints between stages
What are tumors?
abnormal growth of tissue
What is cancer?
malignant primary tumor
What is a mutation?
change in the organism’s genetic code
