L13- Mitosis Flashcards
interphase is the
longest part of the cell cycle
what happens in interphase
cell grows and copies its organelles and DNA
mitosis simple
chromosomes align, separate and move into new daughter cells
M
cell division
G1
the cell grows, organelles are copied, mRNA and proteins synthesised in preparation for subsequent steps leading to mitosis
S
DNA replication
G2
= Organelle replication and reorganisation in preparation for mitosis
unreplicated chromosome structure
one chromosome (one chromatid)= one DNA molecule
replicated chromosome structure
one chromosome (two chromatids)= two DNA (identical) molecules
centromere links the
sister chromatids and consists of repetitive sequences
chromosome scan be grouped according to
size and shape
how many chrosmsoems in human cell
46
telomeres are
repetitive sequences at the end of each chromssomes
homologous chromosomes
have the same DNA sequences- the same genes
genes on homologous chromosomes may bey
different variants- alleles
mitosis is
cell division for somatic cells
mitosis produces
two identical daughter cells (same number of chromosome content as parental cell)
how many mitotic rounds during development
50
order of mitosis
Interphase prophase pro metaphase metaphase anaphase telophase cytokinesis
prophase
- Nuclear envelop disintegrates
- Chromosomes condense
- Mitotic spindle starts to forms
prometaphased
Spindles formed which connect to the kinetochore
metaphase
- Chromosomes randomly line up at the metaphase plate
Anaphase
- Kinetochore microtubules contract chromatids towards the poles
- Go to different poles (now become chromosomes (not called chromatids anymore)
telophase
- Spindle disappears
- Nuclear membrane reforms
- Nucleolus reappears
- Chromosomes decondense
cytokinesis
Cleavage of daughter cells with equal number of chromosomes
