Question

1)Jack has freckles, which are a recessive trait. His wife Kelli doesn't have freckles. What % of their children might develop freckles if Kelli is a heterozygote?

2)English Bulldogs often have extra teeth and underbites. The extra teeth are a recessive trait and the underbite is dominant. If you're considering adopting a bulldog with the genotype BbTt use the key below to determine what the dog will look like.

*KEY:  "B" = underbite and  "T" = teeth*

a)the dog will have an underbite but NO extra teeth

b)the dog will have BOTH an underbite and extra teeth

c)the dog will have extra teeth but NO underbite

d)the dog will have neither an underbite, nor extra teeth

3)A farmer has 100 acres of land on which he grows a drought resistant, true -breeding variety of corn. At the end of the growing season he collects and keeps enough seed to replant the following year. What percentage of his crop will be drought resistant the following year?

4)Rebecca is a single mother and knows that the father of her child is one of 2 men that she has a sexual history with. Now that her son is approaching age 5 and wants to know his father she is pursuing genetic testing. Her son was born with poor vision due to a genetic condition known to be recessive. Rebecca's vision is very good/normal. Which of the following genotypes might belong to the father?

*you need to construct Punnett Squares to determine the answer

KEY: use letter A to represent vision

Group of answer choices

a)aa only

b)Aa or aa

c)Aa only

d)AA or aa

Answer 1

1. 50%

freckles is recessive trait .

let say F - dominant allele

f - freckles allele

parent - jack (ff) x kelli (Ff)

gamete - f x F and f

F1-

	F	f
f	Ff (normal)	ff (freckle)

so chance of getting child with freckle is 50%.

2. a)the dog will have an underbite but NO extra teeth

Extra teeth is recessive - t normal teeth dominat - T

underbite is dominant - B normal recessive - b

so BbTt means - Underbite and normal teeth

3. The crop is drought resistant true breeding that means crossing between true breeding will produce the same trait in F1 so there will be 100% chance of getting drought resistance crop in next generation.

4.b)Aa or aa

poor vision allele is recessive - let say - a

so poor vision in child could only develop if the genotype will be aa. Child recieves one allele from each parents that mean one 'a' is coming from normal mother (Aa) and other 'a' is coming from father that could have genotype 'Aa' or 'aa'.