Biology MCQs

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Pure Sugar is sucrose C₁₂H₂₂O₁₁.

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Blue component in light causes suppression of melatonin produced by the pineal gland. Melatonin regulates the sleep–wake cycle. Natural levels of melatonin in the blood are highest at night.

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Red blood cells (RBCs) have an average lifespan of 100-120 days and are produced in the bone marrow, while the spleen is where they are broken down. Macrophages break down RBCs into globin and heme, recycling amino acids and iron for various purposes, including protein synthesis. Some parts of old RBCs are reused in creating new ones. The average lifespan of cells in the human body is 7 to 10 years, but it varies across cell types and organs. Neutrophil cells, for example, last about two days.

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A plant belonging to angiosperms group would show least adaptation to marine water. Angiosperms are vascular plants that have stems, roots, and leaves.

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Gargling with salt water provides relief for a sore throat primarily because it dehydrates water from inflammatory tissues through osmosis. This process reduces swelling and discomfort. Saltwater creates a hypertonic solution, drawing excess fluid out of swollen tissues, which can alleviate pain and irritation. Additionally, salt has mild antibacterial properties, but its primary benefit in this context is osmotic dehydration.

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Epiphytic roots are the roots of some orchid plants, which hang in the air and absorb moisture and nutrients from the air, rain water. Examples of epiphytic roots are mosses, liverworts, lichens, and algae of temperate zone and ferns, cacti, orchids, and bromeliads in the tropics.

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Cleviceps purpurea is an important ascomycete that grows on the grains of rye grass cereals. It produces the drug ergot, which is both a severe poison and a useful medicinal drug. It affects the central nervous system as well as causes the contraction of involuntary muscle. Ergotism, caused by eating infected rye bread, was common in the Middle Ages, when it was known as “St. Anthony’s Fire.

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In biology, tissue is a cellular organizational level between cells and a complete organ. Animal tissues are grouped into four basic types: connective, muscle, nervous, and epithelial.

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The primary route in which the body eliminates substances is through the kidneys. The main function of the kidney is the excretion of body wastes and harmful chemicals into the urine.

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Bacillus Calmette Guérin or BCG is usually given around birth to prevent severe TB in infants. The neonatal immune system is immature. Delaying BCG vaccination from birth to 10 weeks of age would enhance the vaccine-induced immune response. The BCG vaccine is an injection given to children who have a higher risk of catching TB. The BCG vaccine helps your child’s immune system fight the germs that cause TB and helps stop them from getting serious TB disease.