5. Meiosis Flashcards
sexual reproduction is the formation of ___ that is product of ___, and it _____ occur without the ______ process
gametes, meiosis
CANNOT , mitotic
body cells are call ____ cells, they are __ specialized for _____ / these cells are divided by _____
somatic
NOT reproduction
mitosis
somatic cells are _____ _____ of one another and each somatic cell will have #__ copies of the same ______ called _______ ____
genetic copies
2. chromosomes
homologous pairs
homologous pairs are the same _____ but contain slightly different forms of the genes in that ______
chromosome
somatic cells are ____ because they have ______ ______ that have 2 copies of the same chromosome
diploid
homologous pairs
______ is the process that produces ______ cells, these cells contain #__ copy of each chromosome
meiosis
haploid
1
the haploid chromosome # is ___ and the diploid chromosome # is __, why?
1
2
they have 2 copies of each chromosome
_____ cells are the result of fertalization
diploid
______ cell (n) + _____ cell (n) = ______ cell (2n)
haploid = haploid = diploid
the formation of ___ involves the process of taking a ____ cell with 2 copies of each chromsome and turning it into a _____ cell so that when a ____ cell from dad and a _____ cell from mom defuse together it will become a ____ organism once again
(2 / 1 and 1 then 1 + 1 = 2)
gametes , diploid
haploid
haploid
diploid
_____ is the process that produces _____ cells, so it takes the ____ nucleus and through #__ separate round of ______ _______ producing #___ _______ cells.
meiosis , haploid cells , diploid
2 cell diviso n
4 haploid cells
meiosis has #___ ______ ____ but ____ is only replicated ONCE
2 nucelar divisons
DNA
____ reduces the ______ # from diploid tp haploid (2n - n) and this process is ___ (making sure each gamete/prodcut from both cell divisions has the exact right amount of chrosmomes) and it creates a lot of _______ ________ in the products
meiosis , chromsome
orderly
genetic diversity
***** Meisos does 3 things NAME THEM
- reduce chromosome number (diploid to haploid/ 2n to n)
- orderly (makes sure each haploid produces the right set of chromosomes)
- creates genetic diversity
**** why is genetic diversity important?
gives organism a leg iup in a changing environment
EXAMPLE
if we are all clones and had the same genes IF a deadly disease was to come in and we lack resistance WE ALL DIE
BUT because we are all differently genetically coded @ least ONE of us could SURVIVE the deadly disease
SO we don’t all go extinct
we now know meiosis is the formation of gametes so your taking #__ ____ cell with _____ _____ and dividing it once and THEN AGAIN this process is called ….
1 diploid duplicated DNA
Meiosis 1
Meiosis 1 takes a ____ cell with replicated _____ and turning it into #__ ____ cells with duplicated _____
diploid chromsomes
2 haploid chromsomes
After meiosis 1 ______ #__ happens , what happens in this process?
meiosis 2
the splitting of the 2 haploid cells….. so the haploid cell divides the sister chromatid to then form 4 HAPLOID CELLS
***before meiosis 1 starts the cell goes through a stage called ___ phase where it makes?
S
copies of its DNA
so each chromosomes is duplicated so there are 2 identical parts called sister chromatids for each chrosomoe
****during meiosis 1 the _____ _______ pairs (1 from mom and 1 from dad) are ______ into _____ cells. (takes diploid cell to haploid cell)
the result of meiosis 1 is #__ _____ cells with ___ the number of OG chromosomes
homogoulous chromosomes
seperated separate
2 haploid
half
what step in Meiosis is DNA ____ and the _____ start to move to opposite poles
early prophase 1
loose
centrosomes
in _____-_____ 1 DNA ____ so it is easier to ____
mid prophase
condenses
drag
what phase in meiosis? does after chromosomes are condensed into packets , the #___ _____ (2 chromosomes) that make up the homologous pair will _____ (come together) to form a ____
prophase 1
4 chromatids
snuggle
tetrad
**in last prophase 1- pro-metaphase an event happens called _____ ___ so you have #___ ____ chromosomes that formed the _____
***During this phase the ____-____ _____ will cross over one another at an area called ___ (gap/space)
crossing over
2 homologous pairs
tetrad
non-sister chromatids
chiasmata
