Question

genotype and phenotype practice
name
introduction: recall that each organism inherits one allele for a gene from each parent. the combination of genes the organism has is called genotype if the organism inherits two of the same gene, the genotype is homozygous. if it inherits two different genes, it is heterozygous. according to mendel, one of these will be dominant and will be expressed if it is present. it can mask the recessive trait. an organism can only express a recessive trait if it possesses two recessive traits. when recording genotype, two letters are used, a capital letter (d) for the dominant trait and a lower case (d) letter for a recessive. by knowing the genotype of an organism, you can identify its phenotype, how it looks.
homozygous dominant: xx homozygous recessive: xx heterozygous: xx
task: use the available information to identify the genotype and phenotype in each example.

1. for each genotype below, indicate whether it is heterozygous (he) or homozygous (ho)

aa ____ ee __ ii __ mm ____
bb ____ ff __ jj __ nn ____
cc ____ gg __ kk __ oo ____
dd ____ hh __ ll __ pp ____

1. for each of the genotypes below determine what phenotypes would be possible.

a. purple flowers are dominant to white flowers.

• pp ______________
• pp ______________
• pp ______________

b. round seeds are dominant to wrinkled seeds.

• rr ______________
• rr ______________
• rr ______________

c. brown eyes are dominant to blue eyes

• bb ______________
• bb ______________
• bb ______________

d. bobtails in cats are recessive.

• tt ______________
• tt ______________
• tt ______________

Explanation:

Step 1: Analyze Genotype 1 (AA)

Check if alleles are same (homozygous) or different (heterozygous). AA has two same dominant alleles. So it's homozygous (Ho).

Step 2: Analyze Genotype 2 (Ee)

Ee has one dominant (E) and one recessive (e) allele, different alleles. So it's heterozygous (He).

Step 3: Analyze Genotype 3 (Ii)

Ii has different alleles (I and i). So heterozygous (He).

Step 4: Analyze Genotype 4 (Mm)

Mm has different alleles (M and m). So heterozygous (He).

Step 5: Analyze Genotype 5 (Bb)

Bb has different alleles (B and b). So heterozygous (He).

Step 6: Analyze Genotype 6 (ff)

ff has two same recessive alleles. So homozygous (Ho).

Step 7: Analyze Genotype 7 (Jj)

Jj has different alleles (J and j). So heterozygous (He).

Step 8: Analyze Genotype 8 (nn)

nn has two same recessive alleles. So homozygous (Ho).

Step 9: Analyze Genotype 9 (Cc)

Cc has different alleles (C and c). So heterozygous (He).

Step 10: Analyze Genotype 10 (Gg)

Gg has different alleles (G and g). So heterozygous (He).

Step 11: Analyze Genotype 11 (kk)

kk has two same recessive alleles. So homozygous (Ho).

Step 12: Analyze Genotype 12 (oo)

oo has two same recessive alleles. So homozygous (Ho).

Step 13: Analyze Genotype 13 (DD)

DD has two same dominant alleles. So homozygous (Ho).

Step 14: Analyze Genotype 14 (HH)

HH has two same dominant alleles. So homozygous (Ho).

Step 15: Analyze Genotype 15 (LL)

LL has two same dominant alleles. So homozygous (Ho).

Step 16: Analyze Genotype 16 (Pp)

Pp has different alleles (P and p). So heterozygous (He).

For the phenotype part (e.g., part 2a):

Step 17: Analyze Phenotype for PP (Purple dominant)

Dominant allele (P) is present, so phenotype is purple flowers.

Step 18: Analyze Phenotype for Pp (Purple dominant)

Dominant allele (P) is present, so phenotype is purple flowers.

Step 19: Analyze Phenotype for pp (Purple dominant)

Two recessive alleles, so phenotype is white flowers.

(Repeat similar logic for other phenotype questions using Mendel's dominance rules: dominant allele masks recessive; recessive expressed only with two recessive alleles.)

Answer:

(for Genotype Classification - Question 1):
AA: Ho
Ee: He
Ii: He
Mm: He
Bb: He
ff: Ho
Jj: He
nn: Ho
Cc: He
Gg: He
kk: Ho
oo: Ho
DD: Ho
HH: Ho
LL: Ho
Pp: He

(For Phenotype - e.g., 2a:
PP: Purple flowers
Pp: Purple flowers
pp: White flowers
And similar for other parts using dominance of the given trait)