In-Class Assignment 1
For each of the following, determine the possible genotypes and phenotypes of the offspring.
1. Father is heterozygous for the dominant dimple trait and a mother who is homozygous for the recessive dimple trait.
Father
Mother Dimple (D) No Dimple (r) No Dimple (r) No Dimple (r) Genotypes: 2 out of 4 will be heterozygous for the dimple trait and 2 out of 4 will be homozygous recess for the the dimple trait.
Phenotypes: 2 out of 4 chance of having dimples and 2 out of 4 chance of not having dimples. (Some people did not interpret "recessive for dimple trait" as meaning no dimples. If so, and you said that 2 out of 4 chance of having recessive dimple trait " we accepted that as correct.
2. Father is heterozygous for the dominant trait for brown eyes and a mother who is homozygous for the recessive trait blue eyes.
Father
Mother Brown (D) Blue (r) Blue (r) Blue (r) Genotypes: 2 out of 4 (50%) will be heterozygous for eye color (or brown eyes or brown/blue) and 2 out of 4 (50%) will be homozygous recess for eye color (or blue eyes)
Phenotypes: 2 out of 4 (50%) chance of having brown eyes and 2 out of 4 (50%) chance of having blue eyes.
3.(Optional) Father is homozygous for the dominant trait for curly hair and a mother who is homozygous for the recessive trait for straight hair.
Father
Mother Curly (D) Curly (D) Straight (r) Straight (r) Genotypes: All will be heterozygous for hair type (curly/straight)
Phenotypes: All will have curly hair.