misc
true or false:homologous chromosomes are 2 copies of different chromosomes
false= 2 copies of the same chromosome
what is G-2 phase and what is its purpose?
G-2 phase: the phase right before mitosis when the cell duplicates all of its organelles
how many daughter cells does this produce? how many chromosomes are in each daughter cell?
4 daughter cells
23 chromosomes
what is non disjunction? give an example of what it can lead to
non disjunction: when one daughter cell gets an extra chromosome and the other daughter cell has one less chromosome
ex. down syndrome
what are centromeres?
the midpoint of the chromosome where the spindle fibers attach to
what are gametes?
haploid cells involved in sexual reproduction
during which phase do centrioles move to opposite poles of the cell?
prophase
what happens when homologous chromosomes pair up during prophase 1?
synapsis: chromosome one from mom finds chromosome 1 from dad & they pair up making a bivalent
bivalent: pair of each homologous chromosome (23 of these)
what is the purpose of CDKs?
to regulate the cell cycle
what is the purpose of meiosis 2?
to separate 2 sister chromatids
what is the difference between a diploid and haploid cell?
haploid= just one copy of each chromosome (only one parent)
diploid= 2 copies of each chromosome (one from mom and one from dad)
what process of mitosis does the splitting of the cell into 2 daughter cells? explain how this happens
cytokinesis
plants= cell plate forms splitting the cell in 2
animals= contractile ring forms splitting the cell in 2
what happens during crossing over?
bivalence attach at kyasma (certain point) and they break & swap portions of themselves
what activates CDKs?
cyclines
what is a karyotype?
visualization of a DNA genome
what type of cell reproduction is specific to prokaryotes? do they also did mitosis in addition to this?
binary fission
no they do binary fission instead of mitosis
true or false: the 2 daughter cells that are formed are not genetically identical to the parent cell because they can have gene variations
false= they are identical to the parent cell (variations in genes occurs during meiosis)
true or false: pairs of homologous chromosomes line up in the middle during metaphase 1
true
describes the DNA damage checkpoint
the cell checks if the DNA has been damaged before the cell moves to S-phase & gives the cell time to repair the damage before it moves on
***important so that you do not get mutations
what are recombinant chromatids?
true or false: at the end of mitosis you form sister chromatids
false= at the end of mitosis you form 2 daughter cells each with 46 chromosomes
what makes the spindle fibers that attaches to the chromosomes?
centrioles
what is the purpose of meiosis 1?
to make genetically unique haploid cells that when they combine= makes a genetically unique individual
describe how P53 works and how it relates to cancer
P53= tumor suppressor: works to prevent the growth of tumors ***inhibits cell division
oncoe genes: promote cell division
when they are mutated->tell your cells to continuously divide
what is a zygote?
diploid cell that forms when 2 haploid cells (gametes) fuse together (fertilization)