A student is completing a Punnett square for a trait (T/t) that is autosomal and inherited by the dominant allele. The father does not have the trait (tt) but the mother does (Tt). If they had two children, a son and a daughter, what would the completed Punnett square look like (i.e., would the son have the trait, would the daughter have the trait?)(1 point)

Responses

Each child would have a 100% chance of inheriting the trait.
Each child would have a 100% chance of inheriting the trait.

Each child would have a 0% chance of inheriting the trait.
Each child would have a 0% chance of inheriting the trait.

The son would inherit the trait and the daughter would not.
The son would inherit the trait and the daughter would not.

Each child has a 50% chance of inheriting the trait.

1 answer

To determine the chances of the children inheriting the trait, we can complete a Punnett square for the parents' genotypes:

  • Father: tt (homozygous recessive)
  • Mother: Tt (heterozygous)

The possible gametes from each parent are:

  • Father can only contribute: t
  • Mother can contribute: T or t

The Punnett square would look like this:

              T       |       t
          -------------------
        t  |   Tt (trait)  |  tt (no trait)
          -------------------
        t  |   Tt (trait)  |  tt (no trait)

From the Punnett square, we can see the offspring possibilities:

  • 50% chance of Tt (trait)
  • 50% chance of tt (no trait)

So, for each child (son and daughter), there is a 50% chance of inheriting the trait (T) and a 50% chance of not inheriting it (tt).

Thus, the correct response is: Each child has a 50% chance of inheriting the trait.