1. In the absence of sufficient oxygen, our muscle cells undergo anaerobic respiration. In this process, glucose is partially broken down to form lactic acid and a small amount of energy is released. This lactic acid accumulates in muscles, causing pain and fatigue after heavy exercise. When enough oxyRead more

    In the absence of sufficient oxygen, our muscle cells undergo anaerobic respiration. In this process, glucose is partially broken down to form lactic acid and a small amount of energy is released. This lactic acid accumulates in muscles, causing pain and fatigue after heavy exercise. When enough oxygen becomes available, lactic acid is converted back to carbon dioxide and water. Thus, the correct answer is that lactic acid and energy are produced during anaerobic respiration in human muscle cells. The correct option is (B).

    See less
    • 114
  2. The correct answer is Cuscuta, ticks, lice, leeches, and tapeworm. All these organisms obtain food from other living beings, showing a parasitic mode of nutrition. Parasites absorb nutrients from the host’s body, harming it in the process. Cuscuta sucks nutrients from plants, while ticks, lice, leecRead more

    The correct answer is Cuscuta, ticks, lice, leeches, and tapeworm. All these organisms obtain food from other living beings, showing a parasitic mode of nutrition. Parasites absorb nutrients from the host’s body, harming it in the process. Cuscuta sucks nutrients from plants, while ticks, lice, leeches, and tapeworms live on or inside animals to absorb food. Unlike autotrophs, they cannot prepare their own food and depend entirely on their hosts for survival and nourishment. The correct option is (C).

    See less
    • 26
  3. (i) 12 Ω lamps (only) on. (a) 4 Ω lamps (only) on (ii) 12 V for both sets of lamps and all of them are in parallel. (iii) 12 Ω lamps are on when the wire is connected to position 2. Voltage across both 12 Ω lamps = 12 V. V = IR (Ohm’s law). I = 1A. 4 Ω lamps are on when the wire is connected to posiRead more

    (i) 12 Ω lamps (only) on.

    (a) 4 Ω lamps (only) on

    (ii) 12 V for both sets of lamps and all of them are in parallel.

    (iii) 12 Ω lamps are on when the wire is connected to position 2.

    Voltage across both 12 Ω lamps = 12 V.

    V = IR (Ohm’s law).

    I = 1A.

    4 Ω lamps are on when the wire is connected to position 3.

    Voltage across both 4 Ω lamps = 12 V.

    V=IR (Ohm’s law).

    I = 3A.

    See less
    • 128
  4. In plants, cytokinin is present in areas of rapid cell division, such as the shoot apex, root tips, and young fruits. It promotes cell division, growth, and delay of aging in leaves. On the other hand, abscisic acid (ABA) acts as a growth-inhibiting hormone, responsible for inducing dormancy in seedRead more

    In plants, cytokinin is present in areas of rapid cell division, such as the shoot apex, root tips, and young fruits. It promotes cell division, growth, and delay of aging in leaves. On the other hand, abscisic acid (ABA) acts as a growth-inhibiting hormone, responsible for inducing dormancy in seeds and buds. It also helps plants withstand stress conditions like drought by closing stomata to reduce water loss. Hence, cytokinin promotes growth, while abscisic acid restricts it.

    See less
    • 40
  5. Sameer is suffering from diabetes mellitus, a disease in which blood sugar levels remain high due to insufficient production or improper utilization of insulin hormone. Insulin, secreted by the β-cells of the islets of Langerhans in the pancreas, helps regulate glucose levels by converting excess suRead more

    Sameer is suffering from diabetes mellitus, a disease in which blood sugar levels remain high due to insufficient production or improper utilization of insulin hormone. Insulin, secreted by the β-cells of the islets of Langerhans in the pancreas, helps regulate glucose levels by converting excess sugar into glycogen. Lack of insulin leads to increased glucose in the blood and urine. Reducing sugar intake and regular exercise help maintain healthy blood glucose levels and control the effects of diabetes.

    See less
    • 125