To determine the probability of offspring being a short plant when two heterozygous tall pea plants are crossed, we can use a Punnett square.
Let:
- T = tall allele (dominant)
- t = short allele (recessive)
Since both parent plants are heterozygous, their genotypes are Tt.
When we cross Tt with Tt, the possible combinations of the offspring are:
- TT (tall)
- Tt (tall)
- Tt (tall)
- tt (short)
The combined results give us:
- TT: 1
- Tt: 2
- tt: 1
So the ratios are:
- Tall (TT or Tt): 3
- Short (tt): 1
This results in 1 out of 4 offspring being short (tt).
Therefore, the probability of an offspring being a short plant is:
25%