cell division Flashcards
cell continuity
all cells develop from pre-existing cells
chromosomes
coiled threads of DNA (which form genes) and protein that becomes visible in the nucleus at cell division
purpose of cell division
replace old and damaged cells with new ones
somatic cell
non sex cells
gametes
sex cells
chromosome makeup
60% protein
40% DNA (deoxribonucleic acid)
chromosome amounts in organisms
every organism has a fixed amount of chromosomes (46 in humans)
haploid (n)
single set of chromosomes eg. 23 in gametes
diploid (2n)
double set of chromosomes eg, 46 in cheek cells
n= 23 so 2n=…
46
boy
44:xy
girl
44:xx
autosomes
non sex cells i.e, the numbered cells
who determines sex of child?
man determines due to y chromosome
gene
a section of DNA that contains the instructions for the formation of a protein. they are also the units of inheritance
homogolous pair
two similar genes, in a diploid
cell cycle
the changes that take place in a cell during the period between 1 division and the next
how is the cell cycle divided up?
90% interphase
10% cell division
chromatin
what nucleus looks like in interphase
mitosis
diploid=>diploid
somatic cells
two clone daughter cells
meiosis
diploid=>haploid
-form sex cells
-different genetic info from mother
-4 daughter cells
-not identical - variation
purpose of mitosis in multicellular organisms
growth and repair cells
purpose of mitosis in unicellular organisms
form of reproduction in bacteria/ amoeba
interphase
- cell v.active
- new organelles formed eg, mitochondria
- build up of protein and enzymes
- at end the chromosomes appear doubled
*half will go in each cell
