Question

Certain plants and animals rely on toxins such as cardiac glycosides for self-defense. Digitoxin and bufalin, structurally similar toxins produced by foxglove plants and bufonid toads, respectively, are one such example. Which one of the following statements about these toxins is correct?

• A. They are structural and functional analogs.
• B. They are structural and functional homologs.
• C. They are structural analogs and functional homologs.
• D. They are structural homologs and functional analogs.

Hint:

Analogous structures or functions arise independently, while homologous traits arise due to shared ancestry.

Answer 1

The Correct Option is A

Step 1: Understand the concept of analogs and homologs.
Homologs are similar structures or functions that arise from shared ancestry, while analogs are similar traits or functions that arise independently, typically due to similar selective pressures.
Step 2: Explanation.
The toxins produced by foxglove plants and bufonid toads are structurally similar (both are cardiac glycosides) and have similar biological functions (toxic defense mechanisms), but they evolved independently in these organisms. Hence, they are structural and functional analogs, not homologs.