3)
2)
ALIEN GENETICS (ANSWERS)
1) Answer: 0%
Trait: Body Color
Alleles: (Y) Yellow or (y) orange
Cross: Heterozygous male (yellow, Yy) vs. Pure Yellow Female (YY)
Y Y
Y y
YY
Yy
YY
Yy
Orange = Recessive Phenotype = Recessive Genotype = yy
Hybrid vs. pure (Test Cross) --> Same as parents!!
Genotypes / Genotype Ratio = Same as parents, in this case: 50% Yy & 50% YY (1 : 1)
Phenotypes / Phenotype Ratio = Same as parents, in this case: 100% Yellow!
Therefore, chances of an orange baby = 0%
(As per Punnett Square to the side)
P
Answer: 25%
Trait: Eye Color
Alleles: (P) Purple or (p) White
Cross: Purple-Eyed Hybrid (Pp) vs. Purple-Eyed Hybrid (Pp) p
P
PP
Pp p
Pp pp
Homozygous recessive = pp
Hybrid vs. Hybrid (F1 Cross) -->
Genotype: 25% Pure Dominant; 50% Hybrids; 25% Pure Recessive (1 : 2 : 1)
Phenotype: 75% Dominant; 25% Recessive (3 : 1)
Therefore, chance of homozygous recessive = 1/4 or 25%
(As per Punnett Square to the side)
Answer: 50%
Trait: # of Body Rings
Alleles: (R) 3 or (r) 5
Cross: Heterozygous female (3 rings, Rr) vs. 5-ringed male (recessive phenotype = rr) r r
R
Rr
Rr r rr rr
Mother look or phenotype = Dominant, or 3 rings (RR or Rr genotype will be expressed as 3 rings)
Hybrid vs. pure (Test Cross) --> Same as parents!!
Genotypes / Genotype Ratio = Same as parents, in this case: 50% Rr & 50% rr (1 : 1)
Phenotypes / Phenotype Ratio = Same as parents, in this case: 50% 3 ring; 50% 5-ring
Therefore, chance of looking like mother (Rr or RR) is 2/4 = 1/2 = 50%
(As per Punnett Square to the side))

4) y
Answer: 100%
Trait: Body Color
Alleles: (Y) Yellow or (y) orange
Cross: Pure dominant male (yellow, YY) vs. Homozygous recessive female (green, yy)
Y
Yy
Y
Yy
Hybrid gene = Yy
Remember Pure vs. Pure (P Cross) --> 100% Hybrids
Therefore, 100% change of hybrid
(As per Punnet Square to the side) y Yy Yy
5) Answer: 50%
Trait: # of Antennae
Alleles: (A) 2 or (a) 1
Cross: 1-antennae male (recessive trait, aa) vs. Heterozygous 2-antennae female (Aa) a a
A
Aa aa a
Aa aa
Recessive phenotype = Recessive Genotype = aa
Hybrid vs. pure (Test Cross) --> Same as parents!!
Genotypes / Genotype Ratio = Same as parents, in this case: 50% Aa & 50% aa (1 : 1)
Phenotypes / Phenotype Ratio = Same as parents, in this case: 50% 1-antennae; 50% 2
Therefore, chance of a recessive phenotype (aa) = 2/4 = 1/2 = 50%
(As per Punnet Square to the side)
6)
E
Answer: 75%
Trait: Eyesight
Alleles: (E) Glasses needed or (e) Glasses not worn
Cross: Heterozygous male (Ee) vs. Phenotypically dominante female carrying recessive allele (same as a hybrid, Ee) e
E
EE
Ee e
Ee ee
Wear glasses = Dominant Phenotype = EE or Ee
Hybrid vs. Hybrid (F1 Cross) -->
Genotype: 25% Pure Dominant; 50% Hybrids; 25% Pure Recessive (1 : 2 : 1)
Phenotype: 75% Dominant; 25% Recessive (3 : 1)
Therefore, chance of a Dominante Phenotype (EE or Ee) = 3 to 1 or 75%
(As per Punnet Square to the side)
7) Answer: 50%
Trait: # of Body Rings
Alleles: (R) 3 or (r) 5
Cross: 3-ringed female carrying both dominant and recessive (hybrid, Rr) vs. Recessive phenotype male (rr) r r
R
Rr
Rr r rr rr
Genetically pure baby = Homozygous = RR or rr
Hybrid vs. pure (Test Cross) --> Same as parents!!
Genotypes / Genotype Ratio = Same as parents, in this case: 50% Rr & 50% rr (1 : 1)
Phenotypes / Phenotype Ratio = Same as parents, in this case: 50% 3-rings; 50% 5-rings
Therefore, chance of a pure baby = 2/4 = 1/2 = 50%
(As per Punnet Square to the side)