Question

Study the following and choose the incorrect statements
I. In stabilizing selection, the organisms with average phenotype are preserved, whereas extreme individuals of both sides are eliminated
II. Movement of genes from one population to the other is called directional selection
III. Centripetal selection operates when homogeneous environment changes into a heterogeneous type
IV. Genetic drift is related to small populations

• A. I, II
• B. III, IV
• C. II, III
• D. I, IV

Hint:

{Types of Selection:}

• {Stabilizing (Centripetal):} Favors Mean. Graph narrows.
• {Directional:} Favors one extreme. Graph shifts.
• {Disruptive (Centrifugal):} Favors both extremes. Graph forms two peaks.

Answer 1

The Correct Option is D

\Note: There appears to be a typo in the question text. The question asks to choose the "incorrect" statements, but the answer key (Option 4) points to statements I and IV. Statements I and IV are biologically Correct, while II and III are Incorrect. Therefore, the question likely intended to ask for the "correct" statements. The solution below explains the validity of each statement. Step 1: Analyze Statement I:
"In stabilizing selection, the organisms with average phenotype are preserved..."
This is the correct definition. Stabilizing selection favors the mean and eliminates peripheral/extreme phenotypes.
Status: Correct.
Step 2: Analyze Statement II:
"Movement of genes from one population to the other is called directional selection."
This is incorrect. Movement of genes is called Gene Flow or Gene Migration. Directional selection is a shift in the population mean due to selection pressure.
Status: Incorrect.
Step 3: Analyze Statement III:
"Centripetal selection operates when homogeneous environment changes into a heterogeneous type."
Centripetal selection is another term for Stabilizing selection (selection towards the center). A change to a heterogeneous environment typically drives Disruptive (Centrifugal) selection, favoring extremes.
Status: Incorrect.
Step 4: Analyze Statement IV:
"Genetic drift is related to small populations."
This is correct. Genetic drift (random change in allele frequency) has a significant impact only in small populations (Sewall Wright effect).
Status: Correct.
Step 5: Conclusion:
Statements I and IV are correct. The option corresponding to this set is (D).