GENETICS. Gregor Mendel: “ Father of Genetics ". Gregor Mendel: “ Father of Genetics ". parents were farmers he became ordained as a priest studied science and mathematics at the University of Vienna. Mendel's Experiments:.
Gregor Mendel: “Father of Genetics"
1. Mendel chose true-breedinglines of each plant/trait. (true breeding lines always produced offspring of the same type)
2. He crossed a true breeding plant with a plant of the opposite trait (purple x white). He called this the Parent (P) generation.
3. He recorded data on the offspring of this cross
First Filial (F1) generation.
4. He self-pollinated the F1 offspring
5. He recorded data on the offspring of the second generation as the Second Filial or (F2) generation.
1. The Law of Dominance and Recessiveness- one trait is masked or covered up by another trait
2. Law of Segregation - the two factors (alleles) for a trait separate during gamete formation.
3. Law of Independent Assortment - factors of a trait separate independently of one another during gamete formation.
Ex. A flower being purple has nothing to do with the length of the plants stems - each trait is independently inherited.
PP = purple, Pp=purple, pp = white
(P = purplep = white)
Heterozygous: when the alleles are different SIZES, in this case the DOMINANT allele is expressed.
1. Determine the genotypes (letters) of the parents. Bb x Bb2. Set up the punnett square with one parent on each side.3. Fill out the Punnett square
middle. B b
4. Analyze the number ofB
offspring of each type. b
RR = round Rr = round rr = wrinkled
Cross two plants, one that is homozygous round and one that is recessive.
What you have done is called a Monohybrid cross:
HD He hr
The phenotypic ratio would be ____;____
BOTH traits are dominant and therefore both traits show.
Example: A cross between a white rabbit and a brown rabbit produces offspring with brown AND white spots.
EX: Blood type in humans is controlled by three alleles: A, B, and O.
hair color, height, weight, intelligence
This pedigree is for the recessive allele that causes albinism. Albinos are humans that have no pigment, their skin is very pale and all of their hair is white, including their eyebrows and eyelashes.
Label each part of the pedigree below. How would you designate a carrier?
This pedigree shows how albinism can be inherited over 2 generations.
Human genetics can also be studied by looking at identical twins, which help establish whether NATURE or NURTURE influences our traits.
Huntington’s Disease effects
the brain’s basal Ganglia
so can’t properly