Chapter 4 Lecture 5 - Phases of mitosis and regulation of cell division Flashcards
1
Q
Functions of mitosis
A
- Development of an individual from a one cell fertilized egg
- Growth of tissues
- Replacement of cells that die
- Repair of damaged cells
2
Q
Phases of mitosis (in order)
A
- Prophase
- Metaphase
- Anaphase
- Telophase
3
Q
What happens during prophase
A
- Chromosomes condense
- Nuclear envelope breaks down
- Spindle fibers grow and attach to chromosomes a kinetochore
- Centrioles migrate to poles
4
Q
Spindle Fibers
A
Microtubules that attach to chromosomes and are used to separate them during mitosis
5
Q
What happens during metaphase
A
- Chromosomes align at the midline
- Long fibers reach to the chromosomes
- Short fibers known as astral microtubules anchor the centrioles
6
Q
Astral Microtubules
A
Short fibers that anchor the centrioles
7
Q
What happens during anaphase
A
- Sister chromatids separate
- Each is now known as a daughter chromosome
- Daughter chromosomes migrate to each pole
8
Q
What happens during telophase
A
- Daughter chromosomes cluster on each side of the cell
- Nuclear envelope forms again around each cluster
- Chromosomes begin to uncoil
- Mitotic spindle disintegrates
9
Q
Cytokinesis
A
Division of cytoplasm into two cells
10
Q
What happens during cytokinesis
A
- Cleavage furrow forms
- Organelles are distributed to the two daughter cells
- 2 genetically identical daughter cells are formed
- Cell enters interphase and the cycle begins again
11
Q
What happens during the mitosis checkpoint
A
- Cell stops to ensure that the splitting of centromeres and the separation of sister chromatids is actually complete
- If successful, the remaining stages of mitosis complete
- If unsuccessful, cell pauses and tries to fix the issue, if the error is fixed, then the cell continues with mitosis, if it is not fixed, then it stops and the cell cycle could be ended
