1 / 20

Genetics & Heredity

Genetics & Heredity. Meiosis. Resulting cells have a different genetic configuration than the original cell. End product is 4 haploid gametes 2 divisions occur, not 1 Crossing over may occur 1 replication with 2 divisions. Independent assortment.

vera
Télécharger la présentation

Genetics & Heredity

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Genetics & Heredity

  2. Meiosis • Resulting cells have a different genetic configuration than the original cell. • End product is 4 haploid gametes • 2 divisions occur, not 1 • Crossing over may occur • 1 replication with 2 divisions

  3. Independent assortment • Genes on different chromosomes behave independently during meiosis. • Separate chromosomes will separate into gametes independently of each other.

  4. Meiosis parents Tt Tt T T t t gametes T T t t Male gametes Female gametes

  5. Punnet Squares Tt x Tt= genotype T t T t= gametes

  6. Punnet Squares Tt x Tt= genotype T t x T t= gametes Male gametes t T

  7. Punnet Squares-monohybrid cross Male gametes Tt x Tt= genotype T t x T t= gametes t T T Female Gametes t

  8. Punnet Squares-monohybrid cross Male gametes Tt x Tt= genotype T t x T t= gametes t T T TT Female Gametes t

  9. Punnet Squares-monohybrid cross Tt x Tt= genotype T t x T t= gametes Male gametes T t T TT Tt Female Gametes t

  10. Punnet Squares-monohybrid cross Tt x Tt= genotype T t x T t= gametes Male gametes t T T TT Tt Female Gametes t tT

  11. Punnet Squares-monohybrid cross Tt x Tt= genotype T t x T t= gametes Male gametes t T T TT Tt Female Gametes t tT tt

  12. Punnet Squares-monohybrid cross Tt x Tt= genotype T t x T t= gametes Male gametes t T T TT Tt Female Gametes t tT tt Mendelian Ratios: Genotypic: 1TT: 2 Tt: 1tt Phenotypic: 3 dominant: 1 recessive

  13. Chromosomes and Sex Determination • Human sperm contains 23 chromosomes, 22 of which are autosomes and 1 which is the sex chromosome. Half the sperm have an “X” sex chromosome, the other 1/2 has a “Y” sex chromosome. • The ovum also contains 22 autosomes and 1 sex chromosome; it’s sex chromosome has been designated “X”. • XX zygote= female : XY zygote= male

  14. Gamete combination possibilities • In a situation with Green (yy) and Round (RR) versus yellow (YY) and wrinkled (rr) • gametes would be yy X RR or 4 yR • 4 Yr Heterozygotes for these traits would be • Rr X Yy and the four gametes would be: • YR Yr yR yr

  15. Dihybrid Cross Genotypes: RrYy x RrYy Gametes: What are the gametes

  16. Dihybrid Cross Genotypes: RrYy x RrYy Gametes: RY Ry rY ry RY Ry rY ry

  17. Dihybrid Cross Genotypes: RrYy x RrYy Gametes: RY Ry rY ry RY Ry rY ry Ry RY rY ry RY Ry rY ry

  18. Dihybrid Cross Genotypes: RrYy x RrYy Gametes: RY Ry rY ry RY Ry rY ry Ry RY rY ry RRYY RRYy RY Ry rY ry

  19. Dihybrid Cross Genotypes: RrYy x RrYy Gametes: RY Ry rY ry RY Ry rY ry Ry RY rY ry RRYY RRYy RrYY RrYy RY RRYy RRyy RrYy Rryy Ry RrYY RrYy rrYY rrYy rY RrYy Rryy rrYy rryy ry

  20. Ry RY rY ry RRYY RRYy RrYY RrYy RY RRYy RRyy RrYy Rryy Ry RrYY RrYy rrYY rrYy rY RrYy Rryy rrYy rryy ry Dihybrid Cross Genotypes: RrYy x RrYy Gametes: RY Ry rY ry RY Ry rY ry Mendelian Ratios: R-Y- 9/16 rrY- 3/16 R-yy- 3/16 rryy- 1/16

More Related