Given below are two statements 1 and 2, and two conclusions I and II.…

2021

Given below are two statements 1 and 2, and two conclusions I and II.

    Statement 1: All bacteria are microorganisms.

    Statement 2: All pathogens are microorganisms.

    Conclusion I: Some pathogens are bacteria.

    Conclusion II: All pathogens are not bacteria.

Based on the above statements and conclusions, which one of the following options is logically CORRECT?

  1. A.

    Only conclusion I is correct

  2. B.

    Only conclusion II is correct

  3. C.

    Either conclusion I or II is correct.

  4. D.

    Neither conclusion I nor II is correct.

Attempted by 62 students.

Show answer & explanation

Correct answer: D

Correct conclusion: Neither conclusion I nor II is correct.

  • Given premises:

    1) All bacteria are microorganisms.

    2) All pathogens are microorganisms.

  • Key idea: Both bacteria and pathogens are subsets of the class "microorganisms."

  • Because the premises only place both groups inside a larger class, they do not specify how the two subsets relate to each other.

  • Possible scenarios consistent with the premises:

    • They overlap partially (some pathogens are bacteria) — makes conclusion I true but not II.

    • They are disjoint (no pathogen is a bacterium) — makes conclusion II true but not I.

    • One subset contains the other (all pathogens are bacteria or all bacteria are pathogens) — which would make one of the conclusions true, but this is not guaranteed by the premises.

  • Conclusion: Since the premises do not determine the relationship between bacteria and pathogens, neither "some pathogens are bacteria" nor "no pathogens are bacteria" necessarily follows. Therefore, neither conclusion I nor conclusion II is logically correct.

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