Which of the following statement is incorrect ?

Options

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

Answer

To determine which statement is incorrect, we will analyze each statement one by one:

### Step 1: Analyze Statement A
**Statement A:** Osmoconformers are able to maintain osmotic concentrations of their cells by either physiological or behavioral means.

- **Analysis:** Osmoconformers do not actively regulate their internal osmotic concentration. Instead, their internal osmotic concentration matches that of their environment. They do not have mechanisms for osmotic regulation, so this statement is incorrect.

### Step 2: Analyze Statement B
**Statement B:** Most vertebrates, except the birds and mammals, are unable to thermoregulate.

- **Analysis:** This statement is correct. Most vertebrates, such as reptiles and amphibians, are ectothermic (cold-blooded) and their body temperature is influenced by the external environment. Birds and mammals are endothermic (warm-blooded) and can regulate their body temperature.

### Step 3: Analyze Statement C
**Statement C:** The success of mammals is mainly due to their ability to thermoregulate and live comfortably whether they are in Antarctica or in the Sahara Desert.

- **Analysis:** This statement is also correct. Mammals have the ability to maintain a constant internal body temperature, allowing them to survive in a wide range of environmental conditions. This thermoregulation is a key factor in their evolutionary success.

### Step 4: Analyze Statement D
**Statement D:** None of these.

- **Analysis:** Since we have identified that Statement A is incorrect while Statements B and C are correct, this option is not applicable.

### Conclusion
The incorrect statement is **A**. Therefore, the answer is **A**.

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