A Mendelian experiment consisted of breeding tall pea plants bearing violet flowers with short pea plants bearing white flowers. The progeny all bore violet flowers, but almost half of them were short. This suggests that the genetic make-up of the tall parent can be depicted as
Explanation
Option C (TtWW) is correct. The short parent with white flowers must have the genotype ttww (homozygous recessive for both traits). Since all progeny bore violet flowers, the tall parent must be homozygous dominant for flower colour (WW), ensuring all offspring receive at least one dominant W allele. Since almost half the progeny were short, the tall parent must be heterozygous for height (Tt). When TtWW is crossed with ttww, the progeny are: 50% TtWw (tall, violet) and 50% ttWw (short, violet). This matches the observation that all progeny had violet flowers but approximately half were short.
Solution Steps
Step 1: Identify the recessive parent's genotype as ttww (short, white flowers are both recessive traits)
Step 2: Since all progeny have violet flowers, the tall parent must be WW (homozygous dominant) for flower colour
Step 3: Since approximately half the progeny are short, the tall parent must be Tt (heterozygous) for height
Step 4: Combine findings to determine the tall parent's genotype is TtWW