Flashcards in Mendel's Genetics Deck (34):
Who was Mendel?
worked with pea plants in 1860
Why was Mendel important?
Knew male+female contributed but didn't know how
Described how traits can be passed on from generation to generation
What is true breeding?
Modern term= homozygous
Breeding two homozygous individuals together
What does P stand for?
What does F1 stand for?
first filial generation
What does F2 stand for?
second filial generation
Why did Mendel use peas in his experiments?
he could control pollination
characteristics were easily identifiable
What is the law of segregation?
each individual has 2 factors for each trait
the factors separate (segregate) when gametes are made
each gamete only gets one factor
fertilization gives the new organism two factors for each trait
What are traits controlled by alleles?
dominant and recessive
What is a locus?
spot on chromosome where genes are located
What are the two genotypes?
What is the phenotype?
What is a monohybrid cross?
1 trait, two heterozygotes
In two trait inheritance, are the dominant and recessive genes inherited together?
No, they don't stick together just because they're both dominant or recessive
What are recombinant offspring?
They have different traits than their parents
What are parental-offspring?
They have the same traits as their parents
What is the relationship between the law of segregation and the law of independent assortment?
Whatever genes the parent has, the traits separate (segregate) and then in anaphase (meiosis), they assort randomly
In the law of segregation, each gamete gets __ trait.
In the law of independent assortment, the gametes get __ possible combos of traits.
What is incomplete dominance?
The heterozygote is a blended phenotype but not a blended genotype. (Pink flowers, compared to red and white, or straight, wavy, and curly hair)
What is an example of multiple-allele traits?
ABO blood group- 3 alleles
In the ABO blood group, how many alleles are inherited?
2 of 3
Both Ia and Ib are ____ to i.
Ia and Ib are ____, meaning both will be equally expressed in the heterozygote.
What is epistasis?
One gene alters the expression of another gene
What is an example of epistasis?
Labrador retrievers and coat color (ee in labs)
To determine the probability of two traits occurring together, what must be done?
The probability of the individual traits must be multiplied together
To determine individual probabilities, what must be done?
Each individual trait must be punnet squared, and those probabilities can then be multiplied
Explain Mendel's experiment
He cross-pollinated 1 true breeding tall plant, and 1 true breeding short plant
Harvested the F1 seeds and planted them so they could self pollinate
What is a one-trait testcross?
Used to determine the dominant genotype (PP or Pp)
The recessive is known (pp)
What is polygenic inheritance?
A trait is controlled by 2 or more sets of alleles
Each dominant and recessive trait adds up
Results in a lot of variation (bell curve)
In terms of polygenic inheritance, what are multifactorial traits?
A combination of polygenic and environmental influence
If a person has a certain gene, being in a certain environment can heighten or speed up its expression (HBP disposition, placed in high stress and high sodium intake, develops HBC faster than someone not predisposed to it)
What is pleiotropy?
One gene has multiple physical effects