Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis...
Transcript of Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis...
![Page 1: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/1.jpg)
Meiosis
• The form of cell division by which _____________ with ________ the regular number of chromosomes, are produced.
(complete set of chromosomes) (half the regular number of chromosomes)
• Meiosis is needed for _______________________.
• _______ divisions (____________ and __________).
![Page 2: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/2.jpg)
Meiosis
• Reproductive cells divide to produce ______________ (___________ or ________).
• Gametes have half the regular # of chromosomes.
• This process occurs only in gonads (__________ or ___________).
Male:
Female:
• Meiosis is similar to mitosis with some chromosomal differences.
![Page 3: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/3.jpg)
Spermatogenesis
llll llll
human
sex cell
diploid (2n)
llll
llll
meiosis I
ll
ll
ll
ll
sperm
haploid (n)
meiosis II
haploid (n)
![Page 4: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/4.jpg)
Interphase I
• Similar to mitotic interphase.
• __________________ replicate (S phase).
• Each duplicated chromosome consist of two identical sister chromatids attached at their centromeres.
• Centriole pairs also replicate (in animal cells).
![Page 5: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/5.jpg)
Interphase I
• ______________ and _____________visible.
![Page 6: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/6.jpg)
Meiosis I (four phases)
• Cell division reduces the _______________ number in daughter cells produced by ________________.
• four phases:
a.
b.
c.
d.
![Page 7: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/7.jpg)
Prophase I
• Longest and most complex phase (90%).
• Chromosomes condense.
• _____________ occurs: _________________________
come together to form a ________________.
• ___________ is a pair of ______________________ or four _________________ (sister and non sister
chromatids) that align in Prophase 1
![Page 8: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/8.jpg)
Prophase I - Synapsis
Homologous chromosomes
sister chromatids sister chromatids Tetrad
![Page 9: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/9.jpg)
Homologous Chromosomes
• Are a pair of chromosomes (____________and____________) that are similar in ________ and _______, and which carry _________controlling the same inherited ______________.
• Each __________ (position of a gene) is in the same position on homologues.
• Humans have _____ pairs of homologous chromosomes.
a. 22 pairs of _______________
b. 1 pair of ________________
![Page 10: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/10.jpg)
Homologous Chromosomes
Paternal Maternal
eye color
locus
eye color
locus
hair color
locus hair color
locus
![Page 11: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/11.jpg)
Sex Chromosomes
XX
chromosome - female
XY
chromosome - male
![Page 12: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/12.jpg)
Crossing Over
• Crossing over may occur between non sister chromatids at the ___________ during Prophase 1.
• During crossing over segments of _______________ _____________ overlap, break, and reattach to the other
• Crossing over increases ________________ in the gametes produced
• ____________ (_______________) are the sites of crossing over.
![Page 13: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/13.jpg)
Crossing Over - variation
nonsister chromatids
chiasmata: site
of crossing over variation
Tetrad
![Page 14: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/14.jpg)
Prophase I
centrioles spindle fiber
aster
fibers
![Page 15: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/15.jpg)
Metaphase I • Shortest phase
• ________________ align on the metaphase plate.
• ________________________ occurs: Orientation of homologous pair to poles is random.
![Page 16: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/16.jpg)
Metaphase I
metaphase plate
OR
metaphase plate
![Page 17: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/17.jpg)
Anaphase I
• __________________________separate and move towards the poles.
• Sister chromatids remain attached at their centromeres.
![Page 18: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/18.jpg)
Anaphase I
![Page 19: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/19.jpg)
Telophase I
• Each pole now has ___________________ set of chromosomes.
• ___________________ occurs and _____ haploid daughter cells are formed.
![Page 20: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/20.jpg)
Telophase I
![Page 21: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/21.jpg)
Meiosis II
• There is no interphase II
(or, if it does occur, it is very short)
• There is no more _______________________
• Remember: Meiosis II is similar to mitosis
![Page 22: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/22.jpg)
Prophase II
• same as prophase in mitosis
![Page 23: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/23.jpg)
Metaphase II
• same as metaphase in mitosis
metaphase plate metaphase plate
![Page 24: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/24.jpg)
Anaphase II
• same as anaphase in mitosis
• sister chromatids separate
![Page 25: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/25.jpg)
Telophase II
• Same as telophase in mitosis.
• _____________ form.
• __________________ occurs.
• _________ haploid daughter cells (gametes) are produced.
gametes = ________ or ____________
![Page 26: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/26.jpg)
Telophase II
![Page 27: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/27.jpg)
Genetic Variation
• Important to population as the raw material for __________________ (____________).
• Question:
What are the three sexual sources of
genetic variation?
![Page 28: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/28.jpg)
Answer:
1.
2.
3.
Remember: variation is good!
![Page 29: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/29.jpg)
Fertilization
• The fusion of a __________ and _______to form a ___________.
• A zygote is a fertilized __________
n=23
egg
sperm
n=23
2n=46
zygote
![Page 30: Meiosis - mortierscience.files.wordpress.com€¦ · Metaphase II •same as metaphase in mitosis metaphase plate metaphase plate . Anaphase II •same as anaphase in mitosis •sister](https://reader030.fdocuments.in/reader030/viewer/2022040619/5f2ff2ef6dd45725a419f171/html5/thumbnails/30.jpg)
Question:
• A cell containing 20 chromosomes (diploid) at the beginning of meiosis would, at its completion, produce cells containing how many chromosomes?