Biology MCQs

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Radiations are not a biological agent that causes disease. Its physical agents cause disease along with electricity, pressure, heat, cold, etc.

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4 tall plants and 1 medium height plant is totally impossible outcome of Mendel’s Experiment. Gregor Mendel discovered the fundamental laws of inheritance through his work on pea plants. They concluded that genes come in pairs and are inherited as separate units, one from each parent.

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In most of the species, mitochondrial DNA is passed down from Mother.

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Rings of cartilage are present in the throat, specifically in the trachea or windpipe, to ensure that the air passage does not collapse. These semi-circular rings provide the necessary structural support to keep the airway open regardless of pressure changes that occur during breathing. This is very important for maintaining a clear, open path for air to flow into our lungs for respiration.

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Turner syndrome is a rare chromosomal disorder characterized by partial or complete loss (monosomy) of one of the X chromosomes that affects females. Individuals with Turner syndrome have only 45 chromosomes, including just a single X chromosome. This monosomic has a chromosome complement of 44 autosomes and one X chromosome (44+XO). The abnormal condition probably originates from exceptional egg or sperm with no X chromosome.

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Saprophytes are the organisms which depend for food on dead and decaying material. They secrete digestive substances into the surrounding environment and break down the organic matter into simpler substances. The nutrients thus produced are absorbed directly through the cell membranes of the organisms.

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Animals, such as mammals and birds, that maintain a constant body temperature regardless of the temperature of the surroundings are called warm blooded. These include birds and mammals. Whales are aquatic mammals hence, being mammal, they are warm blooded. The have a thick layer of fats called blubber underneath their skin to maintain temperature even in cold water of oceans.

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Red rot disease is caused by the fungus Glomerella tucumanensis. An older name,Colletotrichum falcatum, is still preferred by some pathologists. Red rot occurs in various parts of the sugar cane plant but it is usually considered a stalk and a seed-piece disease. Its symptoms are highly variable depending upon the susceptibility of the sugarcane variety and the environment.

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Blood clotting occurs at the point of injury to control bleeding from blood vessels. The coagulation of the blood is initiated by the blood platelets. They normally start the clotting process when they’re exposed to the air, such as in a cut or wound. Calcium ions are required for the promotion or acceleration of blood clotting pathways. With the help of vitamin K and calcium, fibrinogen (a protein that reacts with platelets) forms a mesh of tiny threads that collects red blood cells, which plug the open blood vessels as it dries. This is a clot.

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Agar, one of the commercial products obtained from Gelidium and Gracilaria are used to grow microbes and in preparations of ice-creams and jellies. The gelling agent in agar is an unbranched polysaccharide obtained from the cell walls of Gelidium and Gracilaria. For commercial purposes, it is derived primarily from Gelidium amansii. In chemical terms, agar is a polymer made up of subunits of the sugar galactose.