Question

In elves, curled toes (t) is dominant to flat toes (t). If an elf that is heterozygous were crossed with an elf that is homozygous recessive, what possible offspring could there be in the F1 generation?

1) All offspring will have curled toes
2) All offspring will have flat toes
3) Half of the offspring will have curled toes and half will have flat toes
4) The offspring will have a mix of curled and flat toes

Answer 1

In a genetic cross between a heterozygous curled-toed elf (Tt) and a homozygous recessive flat-toed elf (tt), half of the F1 offspring will have curled toes and the other half will have flat toes, exhibiting a 1:1 phenotypic ratio.

Step-by-step explanation:

In the scenario provided, we have a genetic cross between an elf with curled toes that is heterozygous (Tt) and an elf with flat toes that is homozygous recessive (tt). To predict the possible offspring in the F1 generation, we apply Mendelian genetics principles.

First, we identify the genotypes of the parents: the heterozygous elf (Tt), where 'T' represents the dominant allele for curled toes, and 't' represents the recessive allele for flat toes. The homozygous recessive elf is given by (tt). We can then set up a Punnett square to visualize the potential genotypes of their offspring:

• Heterozygous elf (Tt) can produce gametes with alleles T or t.
• Homozygous recessive elf (tt) can only produce gametes with the allele t.

When we cross these gametes, we get the following genotypes:

• Tt - Curled toes (heterozygous)
• tt - Flat toes (homozygous recessive)

The phenotype ratio for the offspring would be:

1. 50% Curled toes (Tt)
2. 50% Flat toes (tt)

Therefore, the correct answer is that half of the offspring will have curled toes and half will have flat toes. This results in a phenotypic ratio of 1:1.