1 / 17

Genetics

Genetics. Ch 9 p164 – 178 Ch 12 p221 - 232. History. Gregor Mendel 1850s “Father of Genetics ” Garden Peas 7 traits Height, flower position, pod color, pod appearance, seed texture, seed color, flower color Selectively self and cross pollinated the plants Obtained pure stains

bjorn
Download Presentation

Genetics

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 Ch 9 p164 – 178 Ch 12 p221 - 232

  2. History • Gregor Mendel 1850s “Father of Genetics” • Garden Peas • 7 traits • Height, flower position, pod color, pod appearance, seed texture, seed color, flower color • Selectively self and cross pollinated the plants • Obtained pure stains • P generation – parents • F1 generation – the kids • Conclusions: • Traits don’t get inherited together • Every organism gets two copies of a trait • Some are dominant, some are recessive

  3. Genotype- • What the genes say • Rr, homozygous recessive, “big big” • Can’t see it • Phenotype- • What the organism looks or pheels like • Fuzzy, brown, tall • Can see it

  4. Vocab Double check • Allele • Trait • Dominant • Recessive • Cross-Pollination • Self-Pollination • Pure • F1 Generation • P Generation • Law of Independent Assortment • Law of Segregation • Genotype • Phenotype • Homozygous • Heterozygous

  5. Probability • - the likelyhood that something will occur • Everytime, doesn’t matter what happened last time • What are the chances of flipping a coin and getting tails? • 1 out of 2 sides = 50% • What if I just flipped a tail? Does that mean next time I WILL get a head? NO WAY!

  6. Study Pages 174 and 175 • Monohybrid cross- • Using a punnett square to predict the chance that an offspring will have a certain trait • 4 boxes • Dihybrid Cross- • Looking at TWO traits at the same time • 16 boxes • Punnett Square- • A tool used to predict offspring • One parent goes on the side, other goes on top • A Test Cross- • Used to determine the genotype of an organism

  7. Practice • Homozygous Recessive X Heterozygous Red (red is dominant to white) • Step one: Choose letter based on dominant trait • Hetero = Rr homo recessive = rr • Step two: draw box, fill in parents • 1st named parent or Female goes on TOP • Step three: fill in offspring (kids) always put capital first • Step four: Interpret • 50% are white • 0% are homo dom • 50% are heterozygous

  8. Test Cross • Take an unknown organism and breed it with a pure recessive. Outcome tells you what the unknown parent was.

  9. You do Practice • Homozygous Dominant Purple X White (Purple is dominant to White) • Heterozygous Fuzzy X Heterozygous Fuzzy (Fuzzy is dominant to smooth) • Homozygous Recessive Short X Heterozygous Tall • Heterozygous Inflated X Homozygous Recessive Constricted • Black Rabbit X Brown Rabbit (hint p175) Black is dominant

  10. Homozygous Dominant Purple X White • Heterozygous Fuzzy X Heterozygous Fuzzy • Homozygous Recessive Short X Heterozygous Tall

  11. Hetero Inflated X Homo Recessive Constricted • Black Rabbit X Brown Rabbit

  12. Types of inheritance • Complete Dominance- • One trait totally over powers the other • Red + White = Red • Incomplete Dominance- • Traits will blend in the heterozygous state • Red + White = Pink • Codominance- • BOTH Traits show up • Red + White = Red + White • Sex-Linked- • Inheritence depends on offsprings sex

  13. incomplete dominance • There isn’t a true dominant phenotype so what letter you use isn’t as important • Homozygous Dominant will be one phenotype • Homozygous Recessive will be another phenotype • Heterozygous will be a phenotype between the first two • RR = Red rr = White Rr = Pink • TT = Tall tt = Short Tt = Medium • BB = Blue bb = Red Bb = Purple

  14. codominance • In this type of inheritance BOTH phenotypes are dominant and BOTH show up • Homozygous Dominant will be one phenotype • Homozygous Recessive will be another phenotype • Heterozygous will show both possibilities • PP = Purple P’P’ = White PP’ = One Purple petal, one White petal • BB = Blue B’B’ = Red BB’ = One Blue feather, one Red feather • RR = Red R’R’ = White RR’ = One Red hair, One white hair (this color is found commonly in horses and is known as Roan)

  15. Sex-linked • The genes for a sex-linked trait are found on the X or Y chromosome. • For Females, XX, it works like complete dominance and they need two recessive copies to have that trait. • For Males, XY, since they only get one copy, a single recessive will cause them to have the trait. • Two common conditions are color blindness and hemophilia

  16. Chances of boys and girls

  17. Can a color blind dad give it to his sons? • NO! The gene is on the X and Dad gives Y’s to his sons

More Related