cell reproduction n mitosis – asexual reproduction –1 cell produces 2 identical cells n meiosis...
TRANSCRIPT
![Page 1: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/1.jpg)
Cell Reproduction
Mitosis – asexual reproduction– 1 cell produces 2 identical cells
Meiosis – sexual reproduction– 1 parent cell produces 4 cells with ½ the
number of chromosomes as the parent
![Page 2: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/2.jpg)
Why Cells Divide
Growth
Repair
Reproduction
![Page 3: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/3.jpg)
When Cells Divide
Surface Area/Volume Ratio determines the maximum size of any cell.
Cells can’t get bigger, so they divide.
![Page 4: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/4.jpg)
Terminology
Parent cells for new daughter cells
Chromosomes contain DNA & genes
Homologous Chromosomes (a pair)
![Page 5: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/5.jpg)
Phases of Mitosis
![Page 6: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/6.jpg)
Interphase
Chromosomes are uncoiled DNA replicates Centrioles replicate
INTERPHASE
DIVISION
![Page 7: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/7.jpg)
Prophase
Chromosomes coil - appear double stranded
Nucleolus & nuclear membrane disappear
Centromere and chromatids are visible Centrioles form aster rays & spindle
fibers as they move to the poles
![Page 8: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/8.jpg)
Metaphase
Double stranded chromosomes individually line up on the equator
Centromeres attach to a spindle fiber CENTROMERE
CHROMATIDCENTRIOLE
![Page 9: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/9.jpg)
Anaphase
Chromosomes split & separate and are pulled to opposite poles of the cell by the spindle fibers
![Page 10: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/10.jpg)
Telophase
Cytoplasm divides (cytokinesis) New nuclear membranes form
![Page 11: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/11.jpg)
Cell Division and Reproduction
Sexual Reproduction– 2 parents needed.– Offspring are similar to, but not
identical to the parents.– Genetic variations contribute to
evolution of species.
![Page 12: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/12.jpg)
Chromosome Number
Each species has a specific chromosome number.
Homologous chromosomes - 2 of a same pair. Have the same number and types of genes. One from egg, other from sperm.
Gametes - reproductive cells. Have half the chromosome number. They have only one chromosome of each pair.
![Page 13: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/13.jpg)
Chromosome Number
Haploid - half chromosome number Sex cells (n)
Diploid - pairs of chromosomes Body cells (2n)
Meiosis - reduction division reduces chromosome number to haploid.
![Page 14: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/14.jpg)
Phases of Meiosis
One DNA replication followed
by two cell divisions.
![Page 15: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/15.jpg)
Interphase I
DNA replicated
Centrioles replicated
![Page 16: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/16.jpg)
Prophase I
Chromosomes coil Centrioles move to poles Spindle fibers and asters form Nuclear membrane disappears Homologous chromosomes
synapse & crossing over occurs
![Page 17: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/17.jpg)
Metaphase I
Homologous chromosomes line up at the equator in pairs
Crossing over occurs between homologs
![Page 18: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/18.jpg)
Anaphase I
Homologous chromosomes separate and move to poles
![Page 19: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/19.jpg)
Telophase I
Cytokinesis occurs forming 2 haploid cells
Cells contain double stranded chromosomes at this point
![Page 20: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/20.jpg)
Interphase II
No DNA replication
Chromosomes uncoil
Centrioles replicate
![Page 21: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/21.jpg)
Rest same as Mitosis
Prophase II - Chromosomes coil.
Metaphase II - Line up on equator.
Anaphase II - Split at centromere and move to opposite poles.
Telophase II - Cytokinesis results in 4 haploid cells.
![Page 22: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/22.jpg)
Spermatogenesis
Sperm cell formation 4 equal sized gametes form
46D46
23D
23D
23
23
23
23
![Page 23: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/23.jpg)
Oogenesis
Egg cell formation 1 large egg + 3 polar bodies (die)
46 46D
23D
23D
23
23
23
23
![Page 24: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/24.jpg)
Mitosis vs. Meiosis
23
46
46
23D 23D
23 23 23 23
Meiosis
Mitosis
Diploid Cells
FertilizationHaploid
Cells
Gametes
Zygote
![Page 25: Cell Reproduction n Mitosis – asexual reproduction –1 cell produces 2 identical cells n Meiosis – sexual reproduction –1 parent cell produces 4 cells with](https://reader036.vdocuments.us/reader036/viewer/2022062804/5697bf871a28abf838c88b56/html5/thumbnails/25.jpg)
Genetic Variations
Sexual reproduction (fertilization)
Meiosis - independent assortment
Meiosis - crossing over
Random Mutations