Biology MCQs

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The spleen, which is located under the ribcage and above the stomach in the left upper quadrant of the abdomen is the largest organ in the lymphatic system. It is that organ where RBC are selectively destroyed/ recycled by macrophages.

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Kwashiorkor disease is caused by the deficiency of proteins. It is also known as “edematous malnutrition”. It is a nutritional disorder most often observed in regions experiencing famine.

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Twins are two offspring produced by the same pregnancy. Twins can be either monozygotic (‘identical’), meaning that they develop from one zygote, which splits and forms two embryos, or dizygotic (‘fraternal’), meaning that each twin develops from a separate egg and each egg is fertilized by its own sperm cell.

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Necrosis is the name of premature death of cells and living tissue. It refers to the death of most or all of the cells in an organ or tissue due to disease, injury, or failure of the blood supply.

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99% of body’s calcium is stored in Bones and teeth. The remainder of the calcium is present in blood, extracellular fluid, muscle, and other tissues. It plays a role in mediating vascular contraction and vasodilation, muscle contraction, nerve transmission, and glandular secretion.

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The primary reason why fruits ripen quicken when stored in a rice container is due to ethylene accumulation. Differences in the rate of ripening between fruits kept in a rice container and a wheat container might be due to the differences in carbon dioxide emission and self heating nature of these grains. Both wheat and rice grains (esp. brown rice) when not completely milled, still actively respire, thus releasing carbon dioxide and energy. Carbon dioxide is a known inducer of ethylene biosynthesis in a number of fruits e.g. tomato. Rice grains without a husk typically have no dormancy and thus respire more at normal storage conditions. Most wheat grains have moderate to high dormancy periods and respire less at normal storage conditions. This is the reason why fruits stored in a rice container ripen faster than the ones stored in a wheat container

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• Octopus: Octopuses belong to the class Cephalopoda within Phylum Molluska. Cephalopoda is a group of highly evolved, predatory marine animals. While they share some common ancestors with mollusks, they have distinct characteristics such as a complex nervous system, a beak-like mouth, and tentacles equipped with suckers.
• Snail: Snails are indeed mollusks. They are part of the class Gastropoda within the phylum Mollusca. Snails have a coiled shell and a soft body.
• Oyster: Oysters are also mollusks. They belong to the class Bivalvia within the phylum Mollusca. Oysters are characterized by their two hinged shells and are known for their filter-feeding lifestyle.
• Starfish: Starfish, also known as sea stars, are not mollusks. They belong to the phylum Echinodermata, and they have a completely different body plan and structure compared to mollusks. Starfish have radial symmetry and a unique water vascular system that helps them move and feed.

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Although a small amount of CO2 is carried by the red blood cells, most is carried as the bicarbonate ion in plasma. Carbon dioxide can travel in the bloodstream in many forms. It can mix with water and form carbonic acid. It can also attach to hemoglobin in red blood cells.

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The Islets of Langerhans are the endocrine cells of the pancreas that produce and secrete hormones such as insulin and glucagon into the bloodstream. The pancreatic hormones, insulin and glucagon, work together to maintain the proper level of sugar (glucose) in the blood.