Gregor Mendel
What is Gregor Mendel often called?
The founder of genetics
Describe the difference between genotype and phenotype
Genotype- genes
Phenotype- physical appearance
Black fur (B) is dominant to grey fur (b). A homozygous recessive mother is crossed with a homozygous dominant father.
What are the genotypes of their offspring?
100% Bb
Black fur (B) is dominant to grey fur (b). A heterozygous mother is crossed with a heterozygous father.
What are the genotypes and the ratios of their offspring?
1/4 BB
1/2 Bb
1/4 BB
Give an example of heterozygous and homozygous
Heterozygous- Aa
Homozygous- AA or aa
How did Mendel ensure the P1 generation would be true breeding?
Allowed them to self pollinate for several generations
Compare the terms trait and allele by giving an example of each
Trait- hair color, eye color, height
Allele- brunette vs blonde, blue vs brown, tall vs short
Which of the following crosses will result in 100% heterozygous offspring?
Cross I P: TT × tt
Cross II P: Gg × Gg
Cross III P: RR × RR
Cross IV P: YY × yy
Cross I: TT x tt
A self-cross between heterozygous purple-flowered pea plants yields a total of 2100 offspring.
How many of those offspring would be purple if it strictly follows Mendel's law? How many would be white?
Purple= 1,575
White= 525
Following the rules of complete or simple dominance:
B= brown
b= blue
What phenotype would be seen with each genotype (BB, Bb, bb)?
BB= brown
Bb= brown
bb= blue
In Mendel's experiments, all of the F1 organisms are what kind of genotype?
Heterozygous or hybrid
What is the law of dominance?
Consider that brown color (B) in naked mole rats is dominant over white color (b). If a brown male naked mole rat was chosen at random and crossed with a white recessive female, producing all brown offspring, the genotype of that male rat would be:
BB
The genes for wing color and size in beetles assort independently. The red color allele (R) of the wing is dominant over the white color allele (r), whereas the normal wing allele (L) is dominant over the short wing allele (l). Determine the phenotypic ratio of red to white-winged offspring produced when a beetle with normal red wings (heterozygous for both traits) is mated with a beetle having short white wings.
2/4 red 2/4 white
or
1:1
Following the rules of incomplete dominance:
R= red
r= yellow
What phenotype would be seen with each genotype (RR, Rr, rr)?
RR= red
Rr= orange
rr= yellow
From his experiments, what did Mendel notice about the phenotypes of the F1 and F2 generations?
F1 all dominant phenotype
F2 3/4 dominant and the hidden trait (recessive) reappeared
Write the term that matches this definition:
alleles separate independently of one another during the formation of gametes
Law of independent assortment
What percentage of offspring will be heterozygous (AaBb) for both gene pairs as a result of a cross between two parents with the genotypes AaBB and Aabb?
50% will be heterozygous (AaBb)
The allele "Y," which produces the yellow color of the seed in the pea plant, is completely dominant over "y," which makes the seed green. The allele for the round shape (R) is completely dominant over the wrinkled shape (r). What will be the phenotypic ratio of a cross between RrYy and RrYy?
9:3:3:1
or
9/16 3/16 3/16 1/16
Following the rules of codominance:
B= black
W= white
What phenotype would be seen with each genotype (BB, BW, WW)?
BB= black
BW= black and white
WW= white
What were the three laws Mendel took away from his experiements?
Law of dominance
Law of segregation
Law of independent assortment
Write the term that matches this definition:
alleles are separated into separate gametes during meiosis
Law of segregation
In a fish, gold skin color (G) is dominant to black skin color (g) and split tail fin (S) is dominant to single tail fin (s). A breeder crosses a male fish having GgSs genotype with a female fish having ggSs genotype. Determine the expected phenotypes and their ratios.
Gold/split = 6/16
Gold/single = 2/16
Black/split = 6/16
Black/single = 2/16
Blue eyes with black coats are not often seen on wolves. Assume that normal coat color (N) dominates over black (n) and that brown eyes (B) dominate over blue (b). An alpha male is mated with an alpha female. What will be the probability of a wolf's offspring having blue eyes and a black coat if both parents are heterozygous for eye and coat color?
1/16 will have blue eyes with black coats
Red feathers (R) are dominant to yellow feathers (r) and long beaks (L) are dominant to short beaks (l). Would would be the genotype of a bird that is heterozygous for feather color and has a short beak?
Rrll