Which of the following is not a postulate of the theory of use and disuse of organ?

Options

A. Development of an organ is directly proportional to it use
B. Acquired character of an organism is transmitted to its offspring
C. Accumulation of variations over a period of time leads to formation of new forms
D. Internal forces tend to increase the size of body

Answer

To answer the question "Which of the following is not a postulate of the theory of use and disuse of organ?", we can follow these steps:

### Step 1: Understand the Theory of Use and Disuse
The theory of use and disuse, proposed by Lamarck, suggests that organisms can develop or lose certain traits based on their usage. For example, if an organ is used frequently, it becomes stronger or more developed, while organs that are not used may diminish over time.

### Step 2: Identify the Postulates of the Theory
The key postulates of Lamarck's theory include:
1. Development of the organ is directly proportional to its use.
2. Acquired characteristics (traits developed during an organism's life) can be passed on to offspring.
3. Internal forces can lead to an increase in body size or complexity.

### Step 3: Analyze the Options
Now, let's analyze the options provided:
1. Development of the organ directly proportional to its use - This aligns with Lamarck's theory.
2. Acquired character of the organism transmitted to the offspring - This also aligns with Lamarck's theory.
3. Internal forces tend to increase the body size - This is consistent with Lamarck's ideas.
4. Accumulation of variation over a period of time leads to the formation of new forms - This does not relate to the use and disuse theory as it refers to genetic variation rather than acquired characteristics.

### Step 4: Identify the Correct Answer
From the analysis, option 4 ("Accumulation of variation over a period of time leads to the formation of new forms") is not a postulate of the theory of use and disuse. Therefore, the correct answer is option 4.

### Final Answer
The answer is option 4: "Accumulation of variation over a period of time leads to the formation of new forms."

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