Cell Division Flashcards
What occurs during interphase
G1 cell grows, organelles prepared to replicate, Synthesis phase is replicated
G2 cell continues to grow
cell checking
Prophase 1
nuclear envelope disappears
nucleolus disappears
Crossing over occurs
chromosomes condense
centrioles move towards the opposite ends
Metaphase1
Independent assortment occurs
homologous chromosomes pair up and line along the metaphase plate (in meiosis) the CHROMOSOMES line up in mitosis
spindle fibres attach to centromeres
G1
cell grows,
organelles prepared to replicate,
Synthesis phase is replicated
g1 checkpoint
damaged DNA
ensures chemicals needed for replication are present
s phase
cells replicate its DNA
ready to divide by mitosis
g2 phase
cells needed for cell division are made
cell keeps growing
g2 checkpoint
ensuing that all of the DNA has been replicated
interphase in mitosis
DNA is replicated
organelles replicate
cell grows
ATP content is increased
Anaphase 1
centromeres divide separating the sister chromatids (mitosis)
homologous pairs separate (meiosis)
Telophase 1
the chromatids (mitosis) and chromosomes (meiosis) reach the opposite poles
nuclear envelope forms around the group of chromosomes
cytokinesis
cytoplasm divided
forms two genetically identical daughter cells
how many cells are at the start of meiosis?
a full number (n)
how many cells are at the end of meiosis?
half the number
how are the cells produced by meiosis genetically different?
crossing over (prophase1)
independent assortment of chromosomes (metaphase 1)
