General Science Questions (MCQs) for Competitive Examinations

Notes:
Leaves are the lungs of plants. Much like the lungs of animals, leaves are the place of a plant’s respiration. It is from leaves that oxygen is emitted during the light hours of the day and carbonic acid gas diffuse in during day and released out at night through stomata.

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Infectious diseases are caused by pathogenic microorganisms, such as bacteria, viruses, parasites or fungi; the diseases can be spread, directly or indirectly, from one person to another. Tuberculosis (TB), infectious disease that is caused by the Tubercle bacillus, Mycobacterium tuberculosis. Chickenpox, also known as varicella, is a highly contagious disease caused by the initial infection with varicella zoster virus Cholera is an infectious disease that causes severe watery diarrhea, which can lead to dehydration and even death if untreated. Diabetes mellitus, commonly known as diabetes, is a metabolic disease that causes high blood sugar. The hormone insulin moves sugar from the blood into your cells to be stored or used for energy.

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Interferons (IFNs) are a group of signaling proteins made and released by host cells in response to the presence of pathogens, such as viruses, bacteria, parasites, or tumor cells. Interferon synthesis occurs primarily in response to viral single-stranded or double stranded RNA that are either the genetic material of RNA viruses or a product of viral transcription. Interferons are named for their ability to “interfere” with viral replication by protecting cells from virus infections.

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Conglobate gland is a leaf like, median, unbranched gland of male cockroach. It lies below the ejaculatory duct and open into the genital pouch close to the male genital aperture.

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Tears are a clear liquid secreted by the lacrimal glands (tear ducts) in the eyes of all land mammals. The lacrimal glands are situated in the upper lateral region of each orbit, in the lacrimal fossa of the orbit formed by the frontal bone. They are paired, almond-shaped exocrine glands, one for each eye.

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The pituitary gland is an endocrine gland that releases growth hormones (GH) for different cells of the body. The most well-known effect in children is to increase height. In adults and children, it helps to control the amount of muscle and fat in the body. It also helps to heal injuries and it promotes the immune system.

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Time required for the organism to eliminate 50 per cent of the total body burden or tissue concentration of chemical is referred to as Half Life Period. A biological half-life or elimination half-life is the time it takes for a substance (drug, radioactive nuclide, or other) to lose one-half of its pharmacologic, physiologic, or radiological activity.

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The process of photosynthesis occurs when green plants use the energy of light to convert carbon dioxide (CO2) and water (H2O) into carbohydrates. Light energy is absorbed by chlorophyll, a photosynthetic pigment of the plant, while air containing carbon dioxide and oxygen enters the plant through the leaf stomata.

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Pyria, or periodontal disease, is a progressive gum disease characterized by inflammation resulting from the toxins found in plaque. It leads to bleeding of the gums. If allowed to progress, Pyria begins to destroy underlying tissue, which may eventually lead to premature tooth loss.

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The foramen magnum (“great hole”) is a large opening in the occipital bone of the cranium. It is one of the circular apertures in the base of the skull (the foramina), through which the spinal cord (an extension of the medulla oblongata) enters and exits the skull vault.