11 Cell Division Meiosis Powerpoint
Transcript of 11 Cell Division Meiosis Powerpoint
![Page 1: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/1.jpg)
Meiosis & Sexual
Reproduction
Lecture 11
![Page 2: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/2.jpg)
________
Transfer of characteristics from parent to
offspring through their
genes
![Page 3: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/3.jpg)
• ________ - Complete complement of an organism’s DNA.
• ___________ - carry genes.
• ______ – “unit of heredity” made of DNA.
![Page 4: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/4.jpg)
Chromosomes & Genes
• Cellular DNA is organized in ______________.
• ______ have specific places on chromosomes.
![Page 5: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/5.jpg)
HomologuesChromosomes exist in homologous pairs in ______
(2n) cells.
Exception: Sex chromosomes (X, Y).
Other chromosomes, known as ___________, they have homologues.
![Page 6: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/6.jpg)
Diploid organisms receive one of each type of chromosome from female parent (maternal chromosomes) and one of each type of chromosome from male parent (paternal chromosomes)
A “matched” pair of maternal andpaternal chromosomes are called___________.
Ploidy – refers to the number of sets of homologous chromosomes in cells● haploid – one copy of each chromosome – designated as “n” (gametes)
● diploid – two copies (= pair) of each chromosome – designated as “2n” (somatic cells)
![Page 7: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/7.jpg)
Karyotype• A karyotype is the complete set of
all chromosomes of a cell of any living organism.
• The chromosomes are arranged and displayed (often on a photo) in a standard format: in pairs, ordered by size.
• Upper right is a typical karyotype of a human male.
• Center is a karyotype showing duplicated homologous chromosomes.
• Lower right is a karyotype of a human sperm.
![Page 8: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/8.jpg)
__________ Reproduction
– Many single-celled organisms reproduce by splitting, budding.
– Some multicellular organisms can reproduce asexually, produce _____ (offspring genetically identical to parent).
– Type of cell division?
![Page 9: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/9.jpg)
_______ Reproduction
• Fusion of two ________ to produce a single zygote.
• Introduces greater genetic variation, allows genetic recombination.
• With exception of self-fertilizing organisms, zygote has gametes from two different parents.
Peter + Lois = Stewie
![Page 10: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/10.jpg)
In humans …
• At fertilization, 23 chromosomes are donated by each parent. (total = 46 or 23 pairs).
• Gametes (sperm/ova):– Contain 22 autosomes and 1 sex chromosome.– Are haploid (haploid number “n” = 23 in humans).
• Fertilization results in diploid zygote.– Diploid cell; 2n = 46. (n = 23 in humans)
• Most cells in the body are produced by _________.
• Only gametes are produced by _________.
![Page 11: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/11.jpg)
Mitosis vs. Meiosis
• 2n
• Clone
• Same genetic information in parent cell and daughter cell.
• Give me another one just like the other one!
• 1n
• Daughter cells different from parent cell and from each other.
• Daughter cells have ½ the number of chromosomes as somatic cell.
• Shuffling the genes(Mix it up!)
![Page 12: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/12.jpg)
Meiosis - Sex Cell (Gamete) Formation
In meiosis, there are 2 divisions
of the nucleus:
meiosis I &
meiosis II
![Page 13: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/13.jpg)
![Page 14: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/14.jpg)
![Page 15: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/15.jpg)
http://www.sumanasinc.com/webcontent/animations/content/meiosis.html
http://www.johnkyrk.com/meiosis.html
Meiosis Animations:
![Page 16: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/16.jpg)
http://www.sumanasinc.com/webcontent/animations/content/meiosis.html
http://www.johnkyrk.com/meiosis.html
Meiosis Animations:
![Page 17: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/17.jpg)
Mitosis vs. Meiosis
![Page 18: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/18.jpg)
![Page 19: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/19.jpg)
Meiosis creates genetic variation
_________• During normal cell growth, mitosis produces daughter
cells identical to parent cell (2n to 2n)
__________• Results in genetic variation by shuffling of maternal
and paternal chromosomes.
• No daughter cells formed during meiosis are genetically identical to either mother or father.
• During sexual reproduction, fusion of the unique haploid gametes produces truly unique offspring.
How is this “shuffling” accomplished?
![Page 20: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/20.jpg)
Genetic shuffling of Meiosis 1
1. Crossing over in Prophase I
2. Independent assortment in Metaphase I.
![Page 21: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/21.jpg)
_______ ______You will also see the terms “synapsis” & “chaisma” associated with this process.
Homologues break at identical locations, then rejoin opposite partners.
This creates new combinations of the alleles on each chromosome.
Occurs randomly several times on every chromosome.
Results in mixing of the genes you inherited from your parents.
![Page 22: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/22.jpg)
Crossing over_________ is the pairing of two homologous chromosomes that occurs during meiosis.
_________ are the sites of crossing over.
Exchange of genetic material between non-sister chromatids.
Crossing over produces recombinant chromosomes.
![Page 23: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/23.jpg)
__________ _________
![Page 24: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/24.jpg)
Meiosis & Sexual Life Cycle
• _____ ______ = sequence of stages in organisms reproductive history; conception to reproduction.
• ________ cells = any cell other than gametes, most of the cells in the body.
• _________ produced by meiosis.
![Page 25: 11 Cell Division Meiosis Powerpoint](https://reader033.fdocuments.us/reader033/viewer/2022051014/55217ba64979597f2f8b552a/html5/thumbnails/25.jpg)
Meiosis Practicing
Each kit should have:- 6 duplicated chromosomes (3 sets of
homologues)
- 4 pieces of string
BEFORE you start writing and doing your Meiosis Worksheet, make sure that you have modeled the stages of Meiosis with the chromosome kits. (If your group needs help, raise your hand & I will come over assist.)