Question

if a pea plants alleles for height are tt, what is true of its parents? (1 point)

both parents were tall.

both parents were short.

both parents contributed (passed on) a recessive allele.

both parents contributed (passed on) a dominant allele.

Explanation:

In pea plants, the allele for short height (t) is recessive, and tall (T) is dominant. A plant with genotype tt has two recessive alleles. Each parent must contribute one allele to the offspring. So, for the offspring to have tt, each parent must have passed on a recessive allele (t).

• "Both parents were tall" is incorrect because tall parents could be TT or Tt, but if both were TT, they couldn't pass on t.
• "Both parents were short" (tt) would pass on t, but it's not the only way (e.g., one Tt and one tt could also result in tt, so this is not necessarily true).
• "Both parents contributed a dominant allele" is wrong because tt has no dominant alleles.

Answer:

C. Both parents contributed (passed on) a recessive allele.