Which of the following components of Larmark’s theory of evolution is considered faulty?

Step 1: Analyze the question We are asked which part of Lamarck's theory is considered faulty (scientifically rejected).

Step 2: Recall the concept Lamarck's theory had these main ideas:

1. Organisms respond to their environment, so individuals of the same species in different environments differ.
2. Use and disuse: organs that are used become better developed, and unused organs degenerate.
3. Inheritance of acquired characters: changes acquired during an organism's lifetime are passed on to offspring.

Step 3: Evaluate each option

• A. Environmental conditions do cause differences between individuals (for example, plants growing in sun and in shade). This is observable and accepted.
• B. Using organs can develop them (for example, exercise builds muscles). This is true within an individual's lifetime.
• C. Unused organs can waste away (for example, muscles shrink with inactivity). This is also observed.
• D. Changes acquired during an organism's life are transmitted to offspring. This is the faulty part. Acquired characters affect only body (somatic) cells, not the gametes, so they are not inherited. A bodybuilder's children are not born with big muscles. Only genetic changes (mutations) in the gametes are passed on. This was the idea disproved by Weismann's experiment, in which he cut off the tails of mice over many generations and the offspring were still born with tails.

Exam tip: Whenever you see "Lamarck" with "faulty" or "rejected", think inheritance of acquired characters. Remember the giraffe's neck: stretching to reach leaves does not make its calves born with longer necks.