Ch.13 meiosis
-
Upload
townview-magnet-center -
Category
Technology
-
view
260 -
download
0
Transcript of Ch.13 meiosis
![Page 1: Ch.13 meiosis](https://reader036.fdocuments.us/reader036/viewer/2022081504/55835fe0d8b42a360c8b4618/html5/thumbnails/1.jpg)
Meiosis & Reproduction
![Page 2: Ch.13 meiosis](https://reader036.fdocuments.us/reader036/viewer/2022081504/55835fe0d8b42a360c8b4618/html5/thumbnails/2.jpg)
Asexual Reproduction
• Identical offspring (clones)
• Mitosis
• Different kinds– Binary fission– Budding– Fragmentation– Regeneration
![Page 3: Ch.13 meiosis](https://reader036.fdocuments.us/reader036/viewer/2022081504/55835fe0d8b42a360c8b4618/html5/thumbnails/3.jpg)
![Page 4: Ch.13 meiosis](https://reader036.fdocuments.us/reader036/viewer/2022081504/55835fe0d8b42a360c8b4618/html5/thumbnails/4.jpg)
Sexual Reproduction
• Two parents
• Genetic variation
• Haploid gametes
• Unique offspring– Similar to parents– Similar to each other
![Page 5: Ch.13 meiosis](https://reader036.fdocuments.us/reader036/viewer/2022081504/55835fe0d8b42a360c8b4618/html5/thumbnails/5.jpg)
![Page 6: Ch.13 meiosis](https://reader036.fdocuments.us/reader036/viewer/2022081504/55835fe0d8b42a360c8b4618/html5/thumbnails/6.jpg)
Genetic VariationFor humans - 23 pairs of chromosomes:
• Independent Assortment – 50/50 chance that gamete gets maternal/ paternal homologous chromosome– # of possible gametes = 223
– >8 million possible gamete combinations
• Random Fertilization– (8 million)(8 million) = 64 trillion possible offspring
• Crossing over – increases genetic variation even more
![Page 7: Ch.13 meiosis](https://reader036.fdocuments.us/reader036/viewer/2022081504/55835fe0d8b42a360c8b4618/html5/thumbnails/7.jpg)
Haploid vs. Diploid
HAPLOID• 1n
• One copy of each chromosome
DIPLOID• 2n
• Two copies of each chromosome
• Homologous chromosomes
![Page 8: Ch.13 meiosis](https://reader036.fdocuments.us/reader036/viewer/2022081504/55835fe0d8b42a360c8b4618/html5/thumbnails/8.jpg)
Karyotyping
![Page 9: Ch.13 meiosis](https://reader036.fdocuments.us/reader036/viewer/2022081504/55835fe0d8b42a360c8b4618/html5/thumbnails/9.jpg)
Human Female Karyotype
![Page 10: Ch.13 meiosis](https://reader036.fdocuments.us/reader036/viewer/2022081504/55835fe0d8b42a360c8b4618/html5/thumbnails/10.jpg)
Human Male Karyotype
![Page 11: Ch.13 meiosis](https://reader036.fdocuments.us/reader036/viewer/2022081504/55835fe0d8b42a360c8b4618/html5/thumbnails/11.jpg)
Life Cycles
![Page 12: Ch.13 meiosis](https://reader036.fdocuments.us/reader036/viewer/2022081504/55835fe0d8b42a360c8b4618/html5/thumbnails/12.jpg)
Overview of Meiosis
• Diploid parent cell divides twice to make haploid gametes
• Homologous chromosomes
• Sister chromatids
![Page 13: Ch.13 meiosis](https://reader036.fdocuments.us/reader036/viewer/2022081504/55835fe0d8b42a360c8b4618/html5/thumbnails/13.jpg)
Meiosis I
![Page 14: Ch.13 meiosis](https://reader036.fdocuments.us/reader036/viewer/2022081504/55835fe0d8b42a360c8b4618/html5/thumbnails/14.jpg)
Meiosis II
![Page 15: Ch.13 meiosis](https://reader036.fdocuments.us/reader036/viewer/2022081504/55835fe0d8b42a360c8b4618/html5/thumbnails/15.jpg)
Mitosis vs. Meiosis
![Page 16: Ch.13 meiosis](https://reader036.fdocuments.us/reader036/viewer/2022081504/55835fe0d8b42a360c8b4618/html5/thumbnails/16.jpg)
Gamete Possibilities(due to Independent Assortment)
![Page 17: Ch.13 meiosis](https://reader036.fdocuments.us/reader036/viewer/2022081504/55835fe0d8b42a360c8b4618/html5/thumbnails/17.jpg)
Crossing Over
• Increases genetic variation
• Synapsis• Tetrad• Chiasma
• Happens during Prophase I
![Page 18: Ch.13 meiosis](https://reader036.fdocuments.us/reader036/viewer/2022081504/55835fe0d8b42a360c8b4618/html5/thumbnails/18.jpg)
Homologous chromosomes move toward opposite poles of a dividing cell during
A. Mitosis
B. Meiosis I
C. Meiosis II
D. Fertilization
E. Binary fission
![Page 19: Ch.13 meiosis](https://reader036.fdocuments.us/reader036/viewer/2022081504/55835fe0d8b42a360c8b4618/html5/thumbnails/19.jpg)
If the DNA content of a diploid cell in the G1 phase is x, then the DNA content of the cell at metaphase I of meiosis would be
A. 0.25x
B. 0.5x
C. x
D. 2x
E. 4x
![Page 20: Ch.13 meiosis](https://reader036.fdocuments.us/reader036/viewer/2022081504/55835fe0d8b42a360c8b4618/html5/thumbnails/20.jpg)
For the same cell, the DNA content at metaphase II of meiosis would be
A. 0.25x
B. 0.5x
C. x
D. 2x
E. 4x
![Page 21: Ch.13 meiosis](https://reader036.fdocuments.us/reader036/viewer/2022081504/55835fe0d8b42a360c8b4618/html5/thumbnails/21.jpg)
How many different combinations of chromosomes can be packaged in gametes by an organism with a diploid number of 8 (2n = 8)?
A. 2
B. 4
C. 8
D. 16
E. 32