Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in...
-
Upload
helen-bates -
Category
Documents
-
view
215 -
download
0
Transcript of Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in...
![Page 1: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/1.jpg)
Fundamentals of Genetics
![Page 2: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/2.jpg)
Gregor Mendel (1822-1884)• Monk from Austria
• He bred pea plants in monastery gardens and used math to interpret his findings
• He is the “Father of Genetics”–Even though he was never recognized
in his lifetime!
![Page 3: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/3.jpg)
Mendel’s Garden Peas• Mendel observed seven
characteristics when using purebred pea plants. Each characteristic trait occurred in two contrasting alleles.
• Traits – a distinguishing characteristic that is inherited such as eye color, leaf shape and tail length.
• Allele – different forms of a trait
![Page 4: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/4.jpg)
Mendel’s Observations• Mendel observed 7 characteristics of pea
plants. ex: - seed color (green or yellow)- seed texture (smooth or wrinkled)- flower color (purple or white)
He used his knowledge of statistics to analyze his observations.
• Crossed plants (mated), collected seeds, recorded observations, then planted seeds, then recorded new plant characteristics.
![Page 5: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/5.jpg)
Mendel’s Methods• Pollination – occurs when pollen grains
produced in the male reproductive parts of a flower (called anthers) are transferred to the female reproductive part of a flower (called stigma).
• Self-pollination – occurs when pollen is transferred from the anthers of a flower to the stigma of either the same flower or a flower on the same plant.
![Page 6: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/6.jpg)
• Cross-pollination – involves pollen transfer with flowers of two separate plants.
• First Mendel snipped off the anthers
• Then he dusted the stigma with pollen taken from the desired father.
![Page 7: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/7.jpg)
• Finally he tied bags over the flowers to keep out any stray pollen.
This gave him control over the pollination of his pea plants (no wind or insects could interfere!)
![Page 8: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/8.jpg)
• He observed that purple-flowering plants grew from the seeds of purple plants, but… he noticed that some white-flowering plants also grew from the seeds of purple-flowering plants.
• Mendel wanted to find an explanation for such variations.
![Page 9: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/9.jpg)
Mendel’s Laws• AKA – Patterns of Inheritance
![Page 10: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/10.jpg)
Mendel Discovered Dominance• 1st Cross= pure Tall x pure Short
Tall X Short All Tall
Tallness = Dominant
Short = Recessive
![Page 11: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/11.jpg)
• Dominance- allele expressed when present in genotype
• Recessive- allele expressed ONLY when two copies are present
![Page 12: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/12.jpg)
Now Breed the Hybrid• 2nd Cross= hybrid Tall x hybrid Tall. Plants self
pollinate (self-fertilize)
Hybrid- containing contrasting alleles
![Page 13: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/13.jpg)
Tall x Tall ?
Results in math:3/4 tall : 1/4 short plantRecessive trait
reappears!!!
![Page 14: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/14.jpg)
![Page 15: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/15.jpg)
1. Law of Segregation•Organisms inherit two copies of each gene/trait = alleles.
•Alleles segregate (separate) during the formation of sperm and eggs.
•Organism donates ONE copy of each gene in fertilization.
![Page 16: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/16.jpg)
AllelesDef: Allele is an alternative form of a gene
(ex: tall and short for PLANT HEIGHT)• One allele T is for tallness• One allele t is for shortness• T allele is dominant over t allele.
Tt = TallTT = Tall
tt = shortCertain traits do not blend!! (no medium height)
![Page 17: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/17.jpg)
Same Phenotype
Different Genotype
TT Tt
![Page 18: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/18.jpg)
Homozygous – when both alleles of a pair are alike. (Ex: TT or tt)
(can be homozygous dominant or homozygous recessive)
Heterozygous – when the two alleles in the pair are different. (ex: Tt)
![Page 19: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/19.jpg)
Punnet Square
• A grid system to predicting all possible genotypes and phenotypes that result from a cross.
• Is a shorthand way of showing how the gametes behave in a cross.
![Page 20: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/20.jpg)
Monohybrid Cross– a cross
between one trait (ex: plant height, OR hair texture)
Tt tt
Tt tt
T t
t
t
![Page 21: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/21.jpg)
Testcross- cross between an organism with homozygous recessive genotype
and a second organism with an unknown genotype.
• The offspring results will show whether the organism with unknown genotype is heterozygous or homozygous dominant.
![Page 22: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/22.jpg)
Dihybrid Crossa cross between two traits (ex: plant height and seed color)
Mendel’s question… are traits inherited together?Ex: Do people with Blond hair always have blue eyes? Do purple flowers always make smooth seeds? Do seeds that are round have to be yellow???
![Page 23: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/23.jpg)
![Page 24: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/24.jpg)
![Page 25: Fundamentals of Genetics. Gregor Mendel (1822-1884) Monk from Austria He bred pea plants in monastery gardens and used math to interpret his findings.](https://reader035.fdocuments.us/reader035/viewer/2022062423/5697bfd41a28abf838cacb52/html5/thumbnails/25.jpg)
2. Law of Independent Assortment
- Traits segregate (separate) independently during the formation of sperm and eggs.
- They then come together again in the new offspring (kid)