Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... ·...
Transcript of Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... ·...
![Page 1: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/1.jpg)
Cell Division & Its Regulation: (Mitosis & Meiosis) (Outline)• Why do cells divide?• New Terms: gamete, zygote, somatic cells, germ cells, haploid, and diploid. • Types of eukaryotic cell division- Mitosis & Meiosis• Cell division of somatic cells and germ line cells.• Comparison of Mitosis & Meiosis in terms of # of cell divisions, # of daughter
cells, DNA content in comparison to mother cell, haploid/diploid state of daughter cells, genetic sameness or variability of daughter and mother cells.
• Cell cycle and its phases; Interphase and the Mitotic phase and events and outcomes of subphases of Interphase: G1, S, G2
• State of chromatin in non-dividing and dividing cells: looses chromatin and condensed chromosome.
• The Mitotic phases: (a) Mitosis: Prophase, Metaphase, Anaphase, Telophase, and (b) Cytokinesis.
• Cytokinesis in animal and plant cells.• Cell Cycle control checkpoints: G1, G2, & M. Cancer cells. • Meiosis and events and outcomes of its two divisions. • Sources of variability in sexually reproducing organisms
![Page 2: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/2.jpg)
Sperm cell (haploid)
NucleicontainingDNA
Egg cell (haploid)
Fertilized eggwith DNA fromboth parents
Embryo cells with copies of same inherited
DNA Offspring with traitsinherited fromboth parents
Zygote (diploid)
Eukaryotic multi-cellular organisms• From gametes -sperm or egg (haploid)• Fertilization of sperm and egg produces zygote
(diploid) • Somatic cells- Body cells of multi-cellular
organism (diploid)
![Page 3: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/3.jpg)
Cell Division & Its Regulation
Key Roles of Cell Division• .• .
Purpose: distribution of genetic material to daughter cells
![Page 4: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/4.jpg)
Types of cell division
Two types in eukaryotic cells:Mitosis produces genetic sameness
(asexual reproduction)Meiosis produces genetic variability
(sexual reproduction)
![Page 5: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/5.jpg)
Eukaryotic Cell division1. Asexual reproduction
(Identical cells)- Unicellular/ Amoeba
- Some multi-cellular eukaryotes plants and some animals like hydra, by budding cells
![Page 6: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/6.jpg)
Eukaryotic Cell division ( cont’d)
2. Sexual reproduction (gametes, non-identical cells- for genetic variety of offspring)
Most multi-cellular organisms have both asexual and sexual reproduction
![Page 7: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/7.jpg)
Cell Reproduction in HumansSomatic cells (sameness)Germ line cells of the gonads (variability)
Mitosis produces 2 genetically identical cellsMeiosis produces 4 genetically non-identical cells each with ½ the number of chromosomes Mitosis and
development
Multicellulardiploid adults
(2n = 46)
Diploidzygote
(2n = 46) 2n
Meiosis Fertilization
Egg cell
Sperm cell
n
Haploid gametes (n = 23)
n
![Page 8: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/8.jpg)
Cell Division• One mother cell divides into two identical
cells following an ordered sequence of events (Cell Cycle)
• Summary of event of dividing cells• Replicate the genetic material• Manufacture additional cellular content• Divide the nucleus• Separate the cytoplasm
![Page 9: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/9.jpg)
Overall Comparison of Mitosis and Meiosis
![Page 10: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/10.jpg)
Interphase with gaps for growthMitosis- division of the nucleusCytokinesis- division of the cytoplasmwww.cellsalive.com
Cell Cycle Phases
![Page 11: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/11.jpg)
Phases of cell Cycle
InterphaseChromosomes duplicate and cell parts are made
MitosisDuplicated chromosomes are evenly distributed
into two daughter nuclei
![Page 12: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/12.jpg)
State of DNA inside a living cell
In a non dividing and in a dividing cell• Packaging of long strands of DNA in small
nucleus (loose chromatin: non-dividing).
• Condensed chromosomes in a dividing cell.
• Chromosomes are visible only when the cell is in the process of dividing during the mitotic phase
![Page 13: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/13.jpg)
Chromatin
![Page 14: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/14.jpg)
Figure 2.3
Replication of Chromosomes
Chromosomes are replicated during S phase prior to mitosis
The result is two sister chromatids held together at the centromere
![Page 15: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/15.jpg)
The mitotic spindle is an apparatus of microtubules that controls chromosome movement during mitosis. It arises from the centrosome.
![Page 16: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/16.jpg)
Figure 2.3
MitosisUsed for growth and repair
Consists of a single division that produces two identical daughter cells
A continuous process divided into 4 sub-phases
- Prophase- Metaphase- Anaphase- Telophase
http://highered.mheducation.com/sites/0072437316/student_view0/chapter11/animations.html#
![Page 17: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/17.jpg)
- Centrosome- a pair of centrioles, microtubule organizing center (MOC).
- Spindle fibers- mirotubules (tubulin)- Nuclear membrane- Nucleolus- Loose chromatin- Condensed chromosome –two sister
chromatids held by centromerewww.cellsalive.com /mitosis http://www.biology.arizona.edu/cell_bio/tutori
als/cell_cycle/cells3.html
![Page 18: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/18.jpg)
Mitosis in a fish blastula
![Page 19: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/19.jpg)
Mitosis in an onion root
![Page 20: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/20.jpg)
Cytokinesis in animal and plant cells
Cleavagefurrow
SEM
140
×
Daughter cells
Cleavage furrow Contracting ring ofmicrofilaments
TEM
7,
500 ×
Cell plateforming
Wall ofparent cell
Daughternucleus
Cell wall New cell wall
Vesicles containingcell wall material
Cell plate Daughter cells
![Page 21: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/21.jpg)
CytokinesisAnimal cells Plant Cells
Cleavage furrowCell plateMicrofilament (actin) and myosin contracting ringGolgi-derived vesicles
![Page 22: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/22.jpg)
Frequency of cell division varies with the type of cell
• Very oftenSkin cellsBone marrowLining of stomach and intestines
• SometimesLiver cells
• Do not divide in mature animal Nerve cells
![Page 23: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/23.jpg)
The Cell Cycle Control SystemThe sequential events of the cell cycle
are directed by a distinct cell cycle control system of regulatory proteins
G2 checkpoint
Control system
M checkpoint
G1 checkpoint
G1
S
G2M
Three major checkpoints are found in the G1, G2, and M phases
www.cellsalive.com
![Page 24: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/24.jpg)
Density-dependent inhibition of cell division
Anchorage dependence of cells
Mortality of cells-limited numbers of cell divisions
Behavior of normal and cancer cells in cell
culture
![Page 25: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/25.jpg)
Tumor
Glandulartissue
A tumor grows from asingle cancer cell.
Cancer cells invadeneighboring tissue.
Cancer cells spread throughlymph and blood vessels toother parts of the body.
Lymphvessels
Bloodvessel
Figure 8.10
Cancer cells- grow out of cell cycle control
- form masses called tumors- malignant tumors spread and invade other tissues
![Page 26: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/26.jpg)
MEIOSIS AND CROSSING OVERGenetic Variability
Chromosomes are matched in homologous pairs
– The somatic (body) cells of each species contain a specific number of chromosomes
– For example human cells have 46 chromosomes making up 23 pairs of homologous chromosomes
![Page 27: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/27.jpg)
Chromosomes are matched in homologous pairs which carry genes for the same characteristics at the same place, or locus
Chromosomes
Centromere
Sister chromatids
Figure 8.12
![Page 28: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/28.jpg)
Meiosis
• Two consecutive cell divisions, meiosis Iand meiosis II
• Results in four daughter cells• Each final daughter cell has only half as
many chromosomes as the parent cell
![Page 29: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/29.jpg)
Meiosis animation• Stages of Meiosis
http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter12/animations.html#
• http://www.sumanasinc.com/webcontent/anisamples/majorsbiology/meiosis.html
• www.cellsalive.com / Meiosis
![Page 30: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/30.jpg)
The results of crossing over during meiosis
![Page 31: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/31.jpg)
![Page 32: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/32.jpg)
Sources of variation in sexually reproducing organisms
1. Independent assortment of chromosomes during meiosis
2. Crossing over during meiosis3. Random fertilization
![Page 33: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/33.jpg)
The results of independent assortment of homologous chromosome pairs at the metaphase plate in meiosis I
![Page 34: Interphase Mitosis Cytokinesis.faculty.sdmiramar.edu/bhaidar/Bio 107 Documents/Lecture... · 2016-10-12 · • Comparison of Mitosis & Meiosis in terms of # of cell divisions, #](https://reader033.fdocuments.in/reader033/viewer/2022041812/5e5827041a490c2b852510af/html5/thumbnails/34.jpg)
Chromosome Abnormalities involving chromosome numbers are caused by non-disjunction of
- Homologous chromosomes during Meiosis I- Sister chromatids during Meiosis II