Asked by Moath Shehadeh on Apr 26, 2024
Verified
A cross is made between two parents with genotypes AaBB and aabb. If there are 32 offspring, how many of them would be expected to exhibit both dominant characteristics?
A) 32
B) 24
C) 16
D) 8
E) 0
Dominant Characteristics
Traits that are expressed in an organism even when only one copy of the gene responsible is present.
Genotypes
The genetic makeup of an organism, consisting of the alleles inherited from both parents.
Offspring
The biological progeny or children of parents.
- Utilize Mendelian genetics principles to forecast results from monohybrid and dihybrid crossings.
- Determine the proportions of phenotypes and genotypes in progeny derived from various genetic crossing methods.
Verified Answer
GA
Grace AlfreyApr 29, 2024
Final Answer :
C
Explanation :
The dominant characteristics are represented by the alleles A and B.
The possible gametes for parent 1 (AaBB) are AB and aB.
The possible gametes for parent 2 (aabb) are ab.
The Punnett square for the cross would be:
| A | a
--|---|--
B | AB | aB
b | Ab | ab
The offspring genotypes and phenotypes would be:
- 25% AaBB (dominant for A and B)
- 25% Aabb (dominant for A)
- 25% aaBB (dominant for B)
- 25% aabb (no dominant characteristics)
Thus, the number of offspring with both dominant characteristics (A and B) would be 25% of 32, which is 8. Therefore, the answer is C.
The possible gametes for parent 1 (AaBB) are AB and aB.
The possible gametes for parent 2 (aabb) are ab.
The Punnett square for the cross would be:
| A | a
--|---|--
B | AB | aB
b | Ab | ab
The offspring genotypes and phenotypes would be:
- 25% AaBB (dominant for A and B)
- 25% Aabb (dominant for A)
- 25% aaBB (dominant for B)
- 25% aabb (no dominant characteristics)
Thus, the number of offspring with both dominant characteristics (A and B) would be 25% of 32, which is 8. Therefore, the answer is C.
Learning Objectives
- Utilize Mendelian genetics principles to forecast results from monohybrid and dihybrid crossings.
- Determine the proportions of phenotypes and genotypes in progeny derived from various genetic crossing methods.