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    Question

    Paragraph for question 21 to 24 Herbicides are chemical substances used to control or kill unwanted plants (weeds). They can be classified into selective herbicides, which target specific plant species without affecting others for example a and non-selective herbicides, which kill all vegetation they come into contact with. Herbicides can also be categorized by their mode of action, such as contact herbicides, which kill only the plant parts they touch, or systemic herbicides, which are absorbed and transported throughout the plant, killing it entirely.

    What is the mode of action for herbicides like atrazine, which affect photosynthesis in plants?

    A They block protein synthesis Correct Answer Incorrect Answer
    B They inhibit the photosystem II in chloroplasts Correct Answer Incorrect Answer
    C They disrupt DNA replication Correct Answer Incorrect Answer
    D They destroy plant cell walls Correct Answer Incorrect Answer
    E They interfere with seed germination Correct Answer Incorrect Answer

    Solution

    Atrazine and other similar herbicides work by inhibiting photosystem II, preventing the plant from performing photosynthesis, ultimately leading to its death.

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