module 2-cell division Flashcards
interphase
DNA replicated and checked for error.
three phases
g1=organelles replicate
s=dna replicate
g2-cell in size replicates and DNA is checked
g0
leaves cycle
could be due to differentiation and damaged DNA.
checkpoints
controls mechanisms of cell
g1=size of cell
g2=dna damage
prophase
chromatin-makes chromosomes visible
nucleous disappears
membrane brakes
spindle fibres form
centrioles to opposite ends.
metaphase
chromosomes moved by spindle fibres, plane in middle=metaphase plate.
anaphase
centrioles divide;
chromatids separated.
telophase
chromatids reached pores turned into
chromosomes, so nuclear envelope forms.
chromosomes uncoil then cytokinesis occurs.
prophase 1
chromosome condense
homologous pairs-DIALUGENTS.
entangled-crossing over.
metaphase 1
pair of chromosomes assemble on metaphase place.
orientation is random and independent.
can be facing at any pole=INDEPENDENT ASSORTEMENT.
anaphase 1
homologous chromosomes pulled to opposite poles.
DNA exchange, as they are entangled, where some parts break or join,CHISTMA=exchange of these.
sister chromatids are not identical
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erthyotes
flat biconcanve shape
transports o2
neutrophills
many lysozymes to attack pathogens
sperm cells
deliver genetic info to female
have tail/flagellum
many mitochondria
acrosome=digestive enzymes
paliside cells
chloroplasts
thin wall for diffusion
large vacuole-mantain turgour pressure.
