In pea plants, tall plants (T) are dominant over short plants (t). If a heterozygous tall pea plant

Question

is crossed with a homozygous recessive short pea plant, what percentage of the offspring is
expected to be tall.
(HINT: use a Punnett square to help you with this question)
(1 point)
75%
0%
25%
50%

Answer 1

To determine the expected percentage of tall offspring from a cross between a heterozygous tall pea plant (Tt) and a homozygous recessive short pea plant (tt), we can use a Punnett square.

Here’s how to set up the Punnett square:

1. The alleles for the heterozygous tall plant (Tt) are T and t.
2. The alleles for the homozygous recessive short plant (tt) are t and t.

Now, fill out the Punnett square:

      T      |      t
-----------------
t |   Tt   |   tt
-----------------
t |   Tt   |   tt

From the Punnett square, we can see the following:

• 2 offspring (Tt) are heterozygous and tall.
• 2 offspring (tt) are homozygous recessive and short.

This gives us:

• 2 tall plants (Tt)
• 2 short plants (tt)

Thus, the ratio of tall to short offspring is 2:2, which simplifies to 1:1.

To find the percentage of tall offspring:

• There are 2 tall plants out of 4 total plants.
• The percentage of tall offspring = (2 tall / 4 total) × 100 = 50%.

Therefore, the expected percentage of the offspring that is tall is 50%.