In pea plants, tall plants (T) are dominant over short plants (t). If a heterozygous tall pea plant is crossed with a homozygous recessive short pea plant, what percentage of the offspring is expected to be tall.

Question

(HINT: use a Punnett square to help you with this question)

(1 point)
Responses

50%
50%

25%
25%

75%
75%

0%

Answer 1

To solve this problem, we can use a Punnett square. The parental genotypes are:

• Heterozygous tall pea plant: Tt (where T is the dominant allele for tallness and t is the recessive allele for shortness)
• Homozygous recessive short pea plant: tt

Now, we can set up the Punnett square:

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

From the Punnett square, we can see the possible offspring genotypes:

1. Tt (tall) - 2 instances
2. tt (short) - 2 instances

Out of the total 4 offspring:

• 2 offspring are tall (Tt)
• 2 offspring are short (tt)

To find the percentage of tall offspring, we use the formula:

\[ \text{Percentage of tall offspring} = \left(\frac{\text{Number of tall offspring}}{\text{Total number of offspring}}\right) \times 100 \]

So, the calculation is:

\[ \text{Percentage of tall offspring} = \left(\frac{2}{4}\right) \times 100 = 50% \]

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