Question

While sitting at home during Movement Control Order (MCO) because of pandemic covid19, observe two different traits of a couple in your family (eg. your mom & dad or your sister & her husband or your brother & his wife, etc). Draw a genetic cross that involves cross of the parents with the chosen 2 pairs of their contracting traits. Imagine that the cross obeys the Mendelian Laws, show the cross and gametes production for each generation (P, F1 and F2). By Using a Punnet square as symbolic representation of the results for the cross, determine the phenotypes, genotypes, phenotypic ratio and genotypic ratio of F2 generation in the family.

Answer 1

Representation:

1. Trait 1:

No freckles= Dominant = FF/Ff

Freckles = Recessive = ff

2. Trait 2:

Blonde hair = Dominant =BB/Bb

Red hair = recessive = bb

Mother:

phenotype = no freckles/ red hair

Genotype = Ffbb (heterozygous for freckles as grandfather had freckles)

Father:

Phenotybe = blonde hair – Freckles

Genotype = ffBb (heterozygous for blonde hair as his parents did not have blonde hair)

Cross:

Ffbb x ffBb

	fB	fb
Fb	FfBb	Ffbb
fb	ffBb	ffbb

Genotype	Phenotype	Probability
FfBb	No freckles- blonde	4/16 =1/4
Ffbb	No freckles- red	4/16 =1/4
ffBb	Freckles- Blonde	4/16 =1/4
ffbb	Freckles red	4/16 =1/4

My phenotype: red hair with freckles, genotype = ffbb

Brother's phenotype: No freckles- blonde hair, genotype = FfBb