Which of the following statements is incorrect ?

Options

A. Osmoconformers are able to maintain osmotic concentration of their cells by either physiological or behavioural means.
B. Most vertebrates, except the birds and mammnals are unable to thermoregulate.
C. Success of mammals is mainly due to their ability to thermoregulate and live comfortably whether they are in Antarctica or in Sahara desert.
D. None of these

Explanation

To determine which statement is incorrect, we will analyze each statement provided in the question step by step.

### Step 1: Analyze the first statement
**Statement:** "Osmoconformers are able to maintain osmotic concentration of their cells by physiological or behavioral means."

- **Explanation:** Osmoconformers are organisms that do not maintain a constant internal osmotic concentration. Instead, their internal osmotic concentration changes according to the external environment. This means they cannot regulate their osmotic balance actively; they conform to the osmotic conditions of their surroundings. Therefore, this statement is incorrect.

### Step 2: Analyze the second statement
**Statement:** "Most vertebrates except the birds and mammals are unable to thermoregulate."

- **Explanation:** Thermoregulation refers to the ability of an organism to maintain a stable internal body temperature regardless of external conditions. Most vertebrates, such as amphibians, fish, and reptiles, are ectothermic (cold-blooded) and cannot thermoregulate effectively. Birds and mammals, however, are endothermic (warm-blooded) and can maintain their body temperature. Hence, this statement is correct.

### Step 3: Analyze the third statement
**Statement:** "Success of mammals is mainly due to their ability to thermoregulate and live comfortably whether they are in low temperature of Antarctica or high temperature and dry conditions of Sahara desert."

- **Explanation:** This statement is accurate. Mammals have the physiological adaptations that allow them to maintain a stable body temperature in diverse environments, which contributes significantly to their success and wide distribution across various habitats. Therefore, this statement is also correct.

### Conclusion
After analyzing all three statements, we find that the first statement regarding osmoconformers is incorrect.

**Final Answer:** The incorrect statement is the first one: "Osmoconformers are able to maintain osmotic concentration of their cells by physiological or behavioral means."

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