6.1-6.3 mitosis and meiosis Flashcards
(14 cards)
what is the hay flick limit?
the maximum number of the cells that can replicate- as every time DNA replicates telomeres at the end shorten
describe the 3 stages of interphase
G1= protein synthesis for organelle replication, cell increases in side
S= DNA is replicated
G2= DNA is hacked for errors, energy and cell size increase.
why are there checkpoints in the cell cycle?
to ensure the cell only divides when fully grown by monitoring and verifying if each phase is completed
what is the G1 checkpoint?
a check for cell size, nutrients, growth factors and DNA damage
what happens if the G1 checkpoint is failed?
the cell going into G0
what is G0 ?
when the cels leave the cell cycle due to:
-differentiation (specialise cells can’t divide )
-damaged DNA
-senescent cells
what does the G2 checkpoint check for?
cell size, DNA replication and damage
what happens in the metaphase checkpoint?
ensures all chromosomes are attached to spindle fibres so mitosis can proceed
how is a chromosome joined?
by a centromere
what are the stages of mitosis?
prophase, metaphase, anaphase, telophase
what causes variation in meiosis?
-crossing over
-independent assortment
which cell division includes gametes?
meiosis
what does meiosis produce?
4 genetically different haploid cells
what does mitosis produce?
2 genetically identical daughter cells
