Cell Division and Cell Cycle Flashcards
(32 cards)
prokaryote and single celled euk - reproduction
binary fission
what do multicellular euk divide for? (4-5)
- tissue growth
- damage tissue repair
- mitosis: reproduction
- meiosis: requires specialized cells = GERM cells
-> specialized division to produce sex cells = GAMETES
what is G0?
some cells never leave interphase - stop dividing
G1, S, G2, M steps
G1: cell grows, normal metabolism, organelles duplicated, prep for S (if needed)
S: DNA replication, chromosome duplication (S=synthesis)
G2: cell grows, prepares for mitosis, DNA is “pseudo-4N”
M: mitosis (karyokinesis): prophase, prometaphase, metaphase, anaphase, telophase, cytokinesis
what is karyokinesis?
division of a cell nucleus during mitosis
which ones keep growing throughout G1, S, G2?
(protein/RNA/DNA)
protein and RNA
(DNA only replicates during S phase)
homologous chromosomes are from?
one from mother
one from father
total # of diff alleles for any given gene is?
> 1
NOT related to number of copies of that allele found in genome
what happens in prometaphase?
chromosomes start to try to align
which specific proteins (2) whose activity fluctuates during cell cycle STOP cell cycle to make assessment (CHECKPOINTS)?
- cyclins
- cyclin-dependent kinases
purpose of checkpoints
- energy and resources are saved (don’t want damaged copy)
- internal control - through internal signals (ex. kinetochores not attached to spindle fibers, delay anaphase) - can be corrected
- external control (ex. growth factors, food)
checkpoints (4)
- G1 checkpoint: (before S phase)
- cell growth
- environment - S checkpoint (during S phase)
- DNA replication - G2 checkpoint (entering mitosis)
- DNA replication
- environment
- cell growth - Metaphase checkpoint (exit mitosis)
- are chromosomes aligned on spindle?
mass of cell must ___ to provide material for daughter cells
double
how to preserve info while making it variable?
meiosis
sexual reproduction: (2 steps)
- production of special reproductive cells, or gamete (1n)
- fusion of gametes (fertilization) - zygote (2n)
gametes produced in specialized tissues (diploid germ cells) through ____ (2n -> n) cell division = meiosis
reductional
what is relationship of germ cell to gametes?
precursor
vertical gene transfer means?
genetic info from parent -> offspring
horizontal gene transfer?
DNA moves between organelles in one organism (mitochondrial DNA -> nucleus)
which organisms have life cycle with sporophyte and gametophyte?
plants and some algae
which organisms can live as a haploid multicellular organism for a while?
plants and some algae
most fungi and some protists
which organisms can make gametes through mitosis?
plants and some algae
most fungi and some protists
number of possible new combinations of chromosomes for a species is 2^n
what is n?
n = haploid # of chromosomes for species
pseudo 2n during?
start of meiosis II, end of meiosis I
