Mitosis Flashcards
1
Q
what is mitosis? what does it actually refer to?
A
nuclear division for form two identical nuclei
2
Q
what must happen BEFORE mitosis?
A
- cell size must increase
- DNA must replicate
- organelles must replicate
3
Q
stages of mitosis
A
PMAT
- prophase
- metaphase
- anaphase
- telophase
4
Q
what happens in early prophase?
A
- chromatin coils and condenses to form chromosomes now visible
- nucleolus disintegrates
- centrioles migrate to opposite poles of cell
- mitotic spindle/spindle fibres form
5
Q
what happens in late prophase?
A
- centromeres attach to spindle fibres
- nuclear envelope has disintegrated
6
Q
what happens in metaphase?
A
- chromosomes aligned along the metaphase plate by spindle fibres
7
Q
what happens during anaphase?
A
FINALLY UNDERSTOOD AH
- centromere divides
- chromatids separate
- 1 chromatid from each original pair pulled to each opposite end by shortening spindle fibres/centromeres
8
Q
what happens during telophase?
A
- each single chromatid at both poles is now called a chromosome
- nuclear envelopes reform around the two sets
- nucleolus reappears
- chromosomes uncoil
- late telophase cytokinesis begins
9
Q
what happens during cytokinesis? general
A
the original cell divides to make two
10
Q
describe cytokinesis in animal cells?
A
- cell surface membrane pulled inwards by the cytoskeleton
- cleavage furrow forms
- invagination takes place
- until the middle is close enough to fuse
- two separate cells formes
11
Q
describe cytokinesis in plant cells?
A
- vesicles from Golgi assemble along the centre (where metaphase plate was)
- fuse with each other and the membrane
- form a phragmoplast
- for later cell wall formation
12
Q
why does cytokinesis happen differently in plant cells?
A
due to rigid cell wall
