lesson 14 Flashcards
eukaryotic chromosomes
different species have different numbers of chromosomes
chromosome number is not correlated with organism complexity
gain or loss of chromosomes is usually fatal
karyotype
the array of chromosomes in a species or individual
Haploid (1n)= complete set of chromsomes necessary to define the species
diploid (2n)= 2 compete sets
originiates through sexual reproductin
eukarytoic chromsome 2
composed of chromatin
heterochromatin is tightly packed not expressed
euckromatin is more loosely-packed and able to be expressed
eukaryotic cell cycle
G1-primary growth phase
s- repliation of DNA
G2-more growth and prep for M pahse
M- nuclear divison + cytoplasmic divison
stages of M phase
Prophase
Prometaphase
Metaphase
Anaphase
Telophase
Cytokinesis
prophase
bipolar spindle assembles
chromosmes condense
prometaphase
chromosomes attach to MTs orient and congress
metaphase
chromsomes align at
anaphase
sister chromatids separrate
chromosomes move to poles
poles further separate
telophase
chromsomes decondence
nucleus begins to reform
cytokinesis
animals: cleavage furrow
plants: cell plate
major cell cycle checkpoints
G1/S
G2/M
M
G1/s
nutrients
cell size
growth factors
G2/M
replication complete
DNA damage
M-spindle checkpoint
chromosomes aligned
