cell division and the cell cycle Flashcards
1
Q
why is cell division important?
A
- cell growth
- repair and replacement of damaged cell parts
- reproduction of species
2
Q
what are the three stages of the cell cycle?
A
- interphase
- mitosis
- cytokinesis
3
Q
chromatin
A
- loose, stringy mass where chromosomes are composed
4
Q
what happens to chromosomes during mitosis?
A
- during mitosis, DNA coils up and individual chromosomes can be seen
- can be single or double stranded
5
Q
centromere
A
- holds double-stranded chromosomes together
6
Q
chromatid
A
- each stand in a replicated chromosome
7
Q
sister chromatid
A
- two identical copies of chromatid connected by a centromere
8
Q
what are the different stages of mitosis?
A
- interphase
- prophase
- metaphase
- anaphase
- telophase
- cytokinesis
9
Q
what happens during interphase?
A
- longest phase of mitosis
- cell is preparing to divide
- growing in size
- making more organelles
- replicating DNA
- cell preforms normal functions
10
Q
what happens during prophase?
A
- chromatin condenses and chromosomes become visible
- nuclear membrane starts to breakdown
- nucleolus disappears
- centrosomes move towards opposite ends of cell, and begin to form spindle fibres
11
Q
what happens during metaphase?
A
- chromosomes line up along the middle of the cell
- centrioles reach opposites of the cell
- each centromere becomes attached
12
Q
what happens during anaphase?
A
- daughter chromosomes are pulled to opposite sides of the cell
- the centromere breaks apart and the chromatids separate
- spindle fibres retract
13
Q
what happens during telophase?
A
- the goodbye
- two daughter nuclei are formed
- spindle fibre starts to disappear
- new nuclear membrane begins to form around the nucleus at each of the cells
- nucleolus appears
- chromosomes reach opposite sides of cell
- chromosomes become less coiled and harder to see
14
Q
what happens during cytokinesis in an animal cell?
A
- ring of special proteins around cell starts to contract
- cell membrane pinching in and forms cleavage furrow
- the contraction pinches the cell membrane until the parent cell is divided into two equal daughter cells
15
Q
what happens during cytokinesis in a plant cell?
A
- golgi bodies stats to produce small vesicles, which carry the materials needed to form a new cell wall
- cell plate grow outwards and join the old cell wall
- the new cell membrane form inside the new cell wal
- the parent cell is divided into two equal daughter cells