Question

Some air-breathing marine vertebrates such as whales, seals, and marine turtles possess adaptations for long, deep dives. Which one or more of the following is/are examples of such adaptations?

• A. Tolerance to hypoxia
• B. Slow heart rate
• C. High levels of haemoglobin
• D. Salt tolerance

Hint:

To identify diving adaptations in marine vertebrates:
1. Look for traits that conserve oxygen or enhance its storage (e.g., bradycardia, haemoglobin levels).
2. Tolerance to hypoxia is a critical survival mechanism for long dives.
3. Distinguish between general marine adaptations (e.g., salt tolerance) and those specific to diving.

Answer 1

The Correct Option is A, B, C

Step 1: Understand adaptations for deep diving. Marine vertebrates that dive for extended periods have evolved specific physiological adaptations to survive underwater where oxygen availability is limited.
These adaptations include:
Tolerance to hypoxia (A): The ability to function under low oxygen conditions enables these animals to remain submerged for long durations.
Slow heart rate (B): A reduction in heart rate, known as bradycardia, conserves oxygen by limiting its consumption during a dive.
High levels of haemoglobin (C): Increased haemoglobin in the blood enhances oxygen storage capacity, allowing these animals to store more oxygen before a dive. Step 2: Analyze salt tolerance (Option D). While marine vertebrates deal with salt regulation due to their habitat, it is not directly related to adaptations for long, deep dives. Step 3: Evaluate the options. Option (A): Correct. Tolerance to hypoxia is essential for surviving long dives.
Option (B): Correct. A slow heart rate conserves oxygen during a dive.
Option (C): Correct. High haemoglobin levels enhance oxygen storage.
Option (D): Incorrect. Salt tolerance is unrelated to deep diving adaptations.