Question

23 a student crossed plants that were heterozygous for the traits of flower color, seed color, and seed shape as part of an investigation designed to verify the results of gregor mendels experiments. the table below displays the results: characteristic offspring phenotypes ratio flower color 705 purple 224 white 3:1 seed color 6,002 yellow 2,001 green 3:1 seed shape 5,474 round 1,850 wrinkled 3:1 based on the information in the table, which of the following is a valid conclusion? (aks 7e) a wrinkled seeds are recessive. b yellow seeds are recessive. c white flowers are dominant. d purple and white flowers are codominant.

Explanation:

To determine the valid conclusion, we analyze the phenotypic ratios (3:1) from the crosses of heterozygous plants. A 3:1 ratio in Mendelian genetics indicates that the dominant trait is more frequent (3 parts) and the recessive trait is less frequent (1 part).

• For seed shape: Round seeds (5,474) are more frequent than wrinkled (1,850) with a 3:1 ratio. So wrinkled (less frequent) is recessive, supporting option A.
• For seed color: Yellow (6,002) is more frequent than green (2,001), so yellow is dominant, eliminating B.
• For flower color: Purple (705) is more frequent than white (224), so purple is dominant, eliminating C.
• Codominance would show both traits equally expressed (e.g., spotted), but here we have a 3:1 ratio (Mendelian dominance), so D is incorrect.

Answer:

A. Wrinkled seeds are recessive.