cell division Flashcards
centromere
middle of a chromosome
- where chromatids meet
sister chromatids
- genetically identical chromosomes
- meet at the centromere
- form 2 daughter cells
daughter cells
- split sister chromatid
chromatin
- arrangement of DNA
- thin and skinny
prokaryote
no nucleus
ex. bacteria
eukaryote
has a nucleus + genetically multicellular
autosomal chromosomes
- the first 22 pairs of chromosomes
(excules the 23rd pair) - in both males and females
homologous pair
- similar in shape and length but NOT identical (like a pair of shoes)
- maternal and paternal pair
somatic cells
- non-gametes
- contains pairs of homologous chromosomes
- diploid (2n)
gametes
- sperm/egg cells
- unpaired chromosomes
- haploid (n)
haploid
- (n)
- one set of each chromosome
diploid
- (2n)
- two sets of each chromosome
the 23rd pair
- sex chromosomes
- homologous in females (XX)
- non-homologous in males (XY)
karyotypes
- pictures of chromosomes
cell cycle
- interphase
- mitotic phase
interphase
- 90% of the cell cycle
- G1 phase
- S phase
- G2 phase
G1 phase
- interphase
- Gap 1 phase
- cell (not chromosomes) is increasing in size and mass
S phase
- synthesis
- copy of DNA is made
- makes sister chromatids
G2 phase
- Gap 2
- makes materials needed for mitosis
- organelles are duplicated
centrosome
- thing that pulls the chrosomes to the north and south pole
mitosis
division of the genetic material
- prophase
- metaphase
- anaphase
- telophase
cytokinesis
division of the cytoplasm
and its organelles into two seperate and identical cells
prophase
- sister chromatids shorten and thicken to form chromosomes
- nuclear membrane disappears
- centrosomes separate and move to opposite poles of the cell
metaphase
- M for middle
- sister chromatids align themselves along the middle
anaphase
- A for apart
- chromatids separate
- spindle fibers pull separated chromosomes to opposite centrosomes
telophase
- spindle fibers dissolve
- nuclear membrane begins to form
- chromosomes begin to lengthen and form chromatin
cytokinesis
- division of the cytoplasm
- cleavage furrow (in animals)
- cell plate (plant cells)
summary of mitosis in animal cells
- prophase
- metaphase
- anaphase
- telophase
- cytokinesis
summary of mitosis in plant cells
- prophase
- metaphase
- anaphase
- telophase
cloning
- process of identical offspring are formed from a single tissue
blastula stage
- embryonic stem cells taken from inner cell mass
identical twins
- monozygotic
- clones
fraternal twins
- dizygotic
- not clones
cancer
- rapid uncontrolled growth of cells
- increases rate of mitosis
meiosis
- gametes formation
- diploid –> haploid
- maintains the chromosome # of a species between
spermatogenesis
spermatogonium, primary spermatocyte, secondary spermatocytes, spermatozoa
oogenesis
oogonium, primary oocyte, secondary oocyte, first polar body, ootid, second polar body, ovum
meiosis 1
- reduction division
- diploid –> haploid
includes: - prophase 1
- metaphase 1
- anaphase 1
- prophase 1
tetrad
homologous pairs line up gene by gene
crossing over
- increases genetic diversity
- exchange of genetic material after intertwining
alleles
diff. forms of genes
ex. A or a
independant assortment
each pair aligns independant from otehr pairs (in metaphase)
meiosis 2
- separation of sister chromatids
- no chromosome duplication between meiosis 1 and 2
compare and contrast meiosis to mitosis !
check notes, pg. 23
