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Gokul

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  1. Asked: June 9, 2021In: Class 10 Science

    Which among the following statements is incorrect for magnesium metal ?

    Best Answer
    Gokul
    Added an answer on December 4, 2021 at 9:31 am

    [B] It reacts with cold water to form magnesium oxide and evolves hydrogen gas. Magnesium metal never reacts with cold water but reacts with both hot water and steam to form magnesium hydroxide and hydrogen gas. Mg(s) + H₂O(l) → Mg(OH)₂ + H₂(g) ↑

    [B] It reacts with cold water to form magnesium oxide and evolves hydrogen gas.
    Magnesium metal never reacts with cold water but reacts with both hot water and steam to form magnesium hydroxide and hydrogen gas.
    Mg(s) + H₂O(l) → Mg(OH)₂ + H₂(g) ↑

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  2. Asked: November 22, 2021In: Class 9 Science

    What is the SI unit of momentum?

    Gokul
    Added an answer on November 23, 2021 at 4:25 am

    [C] kg-ms-1

    [C] kg-ms-1

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  3. Asked: November 22, 2021In: Class 9 Science

    When a rubber Balloon held between the hands is pressed, its shape changes. This happens because:

    Gokul
    Added an answer on November 23, 2021 at 4:25 am

    [A] balanced forces act on the balloon

    [A] balanced forces act on the balloon

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  4. Asked: November 22, 2021In: Class 9 Science

    The rigid outer covering in plant cell is called cell membrane.

    Gokul
    Added an answer on November 23, 2021 at 4:25 am

    [B] False

    [B] False

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  5. Asked: October 15, 2021In: Class 12 Biology

    Elaborate how invasion by an alien species reduces the species diversity of an area.

    Best Answer
    Gokul
    Added an answer on October 16, 2021 at 4:07 am

    Some possible explanations are that the alien species may be i. Vigorously growing and compete with the natural plants for minerals, water etc. The less vigorous local species may be eliminated. ii. Natural pests and predators of the alien species may not be present in the introduced area-leading toRead more

    Some possible explanations are that the alien species may be
    i. Vigorously growing and compete with the natural plants for minerals, water etc. The less vigorous local species may be eliminated.
    ii. Natural pests and predators of the alien species may not be present in the introduced area-leading to proliferation in their number.
    iii. The introduced species may harm the local species by production of chemicals (Amensalism)
    iv. The alien species by proliferation may make conditions unfavourable for the growth of local native plants. (eg. Eichornia).

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  6. Asked: October 15, 2021In: Class 12 Biology

    Name the five key tools for accomplishing the tasks of recombinant DNA technology. Also mention the functions of each tool.

    Best Answer
    Gokul
    Added an answer on October 16, 2021 at 4:07 am

    i. Restriction endonucleases: for cutting the desired DNA at desired places ii. Gel electrophoresis: for separating the desired DNA fragments iii. Ligase enzyme: for creating recombinant DNA molecule. iv. DNA delivery system: like electroporation, microinjection, gene gun method. v. Competant host (Read more

    i. Restriction endonucleases: for cutting the desired DNA at desired places
    ii. Gel electrophoresis: for separating the desired DNA fragments
    iii. Ligase enzyme: for creating recombinant DNA molecule.
    iv. DNA delivery system: like electroporation, microinjection, gene gun method.
    v. Competant host (usually bacteria / yeast): to take up recombinant DNA.

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  7. Asked: October 15, 2021In: Class 12 Biology

    Describe critically the main ideas behind the biological control of pests and diseases.

    Best Answer
    Gokul
    Added an answer on October 16, 2021 at 4:07 am

    Biological control means life against life. It’s a natural and ecofriendly concept. It employs the natural organisms to control the population of pathogens and pests in an ecosystem. Classical examples are Trichoderma which is antagonist against many soil borne plant pathogens. Similarly, PenicilliuRead more

    Biological control means life against life. It’s a natural and ecofriendly concept. It employs the natural organisms to control the population of pathogens and pests in an ecosystem. Classical examples are Trichoderma which is antagonist against many soil borne plant pathogens. Similarly, Penicillium inhibits the growth of Staphylococcus and therefore has been successfully used in the production of Penicillin antibiotic to control many human bacterial pathogens.

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  8. Asked: October 15, 2021In: Class 12 Biology

    In an aquarium two herbivorous species of fish are living together and feeding on phytoplanktons. As per the Gausses principle, one of the species is to be eliminated in due course of time, but both are surviving. How? And what possibly happened to both the species?

    Best Answer
    Gokul
    Added an answer on October 16, 2021 at 4:07 am

    Each species has a specific position or functional role within the community, called niche. According to the Gausses principle, no two species can live in the same niche. In this case, two herbivorous species are living in the same niche and feeding on phytoplanktons. It may be because of the availaRead more

    Each species has a specific position or functional role within the community, called niche. According to the Gausses principle, no two species can live in the same niche. In this case, two herbivorous species are living in the same niche and feeding on phytoplanktons. It may be because of the availability of sufficient phytoplanktons/and or less number of individuals of the fish species. of the two species might have occured. And though neither of the species have been eliminated, niche overlapping may effect the growth and development of individuals of the species.

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