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.

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

(1 point)
Responses

25%
25%

0%
0%

50%
50%

75%

1 answer

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

  1. Parent Genotypes:

    • Parent 1 (heterozygous tall): Tt
    • Parent 2 (homozygous recessive short): tt
  2. Possible Gametes from each parent:

    • Parent 1 can produce gametes: T or t
    • Parent 2 can produce gametes: t or t
  3. Punnett Square:

             T       |       t
           ------------------
         t |   Tt   |   tt
           ------------------
         t |   Tt   |   tt
    
  4. Offspring Genotypes:

    • Tt (tall): 2 squares
    • tt (short): 2 squares
  5. Percentage Calculation:

    • Total offspring: 4 (2 Tt + 2 tt)
    • Tall offspring (Tt): 2 out of 4

Thus, the percentage of tall offspring is: \[ \frac{2}{4} \times 100 = 50% \]

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