Question:medium

Statement I: The change in frequency of a gene that occurs merely by chance and not by selection in small populations is called genetic drift. Statement II: The existence of deleterious genes within the population is called genetic load.

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Genetic Drift = Random chance; Genetic Load = Carrying "bad" genes.
Updated On: Jun 10, 2026
  • Both statements I and II are true
  • Both statements I and II are false
  • Statement I is true but II is false
  • Statement I is false but II is true
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The Correct Option is A

Solution and Explanation

Step 1: Read the two statements.
Statement I defines genetic drift, and Statement II defines genetic load. We must judge if each is correct.

Step 2: Check Statement I.
Genetic drift is the change in how common a gene is, happening just by chance and not by selection, and it shows up strongly in small populations. Statement I says exactly this, so it is true.

Step 3: Understand why small size matters.
In a small group, random events can quickly change which alleles get passed on, so chance has a big effect. This supports Statement I.

Step 4: Check Statement II.
Genetic load is the burden of harmful or deleterious genes carried within a population. Statement II says this, so it is also true.

Step 5: Confirm both ideas are real.
Both genetic drift and genetic load are standard, accepted terms in population genetics, so neither statement is false.

Step 6: Choose the option.
Since both statements are correct, the right choice is that both are true.
\[ \boxed{\text{Both statements I and II are true}} \]
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