Module 1—The Cell Cycle Flashcards
prokaryotic DNA vs eukaryotic DNA
ProkaryotesEukaryotes
- not bound to protein
- circular
- usually no introns
- bound to proteins
- linear
- introns
prokaryotic organelles vs eukaryotic organelles
ProkaryotesEukaryotes
- no membrane-bound organelles
- no nucleus
- 70S ribosomes
- membrane-bound
- nucleus
- 80S ribosomes
prokaryotic reproduction vs eukaryotic reproduction
ProkaryotesEukaryotes
- binary fission
- single haploid chromosome
- mitosis
- meiosis
prokaryotic size vs eukaryotic size
ProkaryotesEukaryotes
* 1-5 μm
- 10-100 μm
3 functions of cell division
- Reproduction
- Growth & development
- Repair & renewal
division produces ______ growth in cell number
exponential
phase in which most adult cells live
G0 or prolonged G1
cell cycle
life of a cell from formation to its own division
DNA is composed of 2 ___________ strands around an imaginary axis, forming a _________
polynucleotide
double helix
direction of polynucleotide strands
antiparallel to one another
5’ and 3’ ends of each
base pairs are situated _______ to helix axis
orthogonally
genome
all DNA in a cell
responsible for production of gametes
germline cells
“spools” for DNA
histones
DNA wrapped around one histone
nucleosome
octamer
8 core histones forming a spool
____ base pairs in a nucleosome
___ base pairs not around a histone
150
20
octamer includes 2 copies of 4 types of histones:
H2A
H2B
H3
H4
function of H1 histones
guide and organize nucleosomes
what do histone tails interact with?
what do they determine?
how is this significant?
nonhistone proteins and other octamers
density of the “wrapping” of the nucleosome
density determines whether genes are “on” or “off”
proteins involved with condensed nucleosomes
condensins
how is DNA condensed during mitosis?
bound into higher order loops by intense cross-linking
basic structure of chromatin
collection of nucleosomes = 30nm fibers
DNA is replicated in ___ phase, in the _______ state
S
chromatin
after copying of DNA, the ________ are formed from the original chromosome and its copy
sister chromatids
how are sister chromatids jointed?
cohesins join them all along their length
they are joined at the centromere most closely
constituents of centromere
repetitive sequences in DNA, mediated by proteins which recognize and bind to centromeric DNA