General Science Questions (MCQs) for Competitive Examinations

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The pituitary gland is a tiny organ, the size of a pea, found at the base of the brain. As the “master gland” of the body, it produces many hormones that travel throughout the body, directing certain processes or stimulating other glands to produce other hormones.

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Plague is caused by bacteria. It is a deadly infectious disease caused by the enterobacteria Yersinia pestis, named after the French-Swiss bacteriologist Alexander Yersin. It has led to death of million of people at one time.

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Capra Hircus is the scientific name of domestic goat or simply goat. It is a subspecies of C. aegagrus domesticated from the wild goat of southwest Asia and Eastern Europe. The goat is a member of the animal family Bovidae and is closely related to the sheep; both are placed in the goat-antelope subfamily Caprinae.

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With its excess secretion, also known as hypersecretion, thyroxine (T4) causes an increased heart rate, high blood pressure, possible palpitations, and could lead to heart failure. It is related to hyperthyroidism.

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The Passenger Pigeon or Wild Pigeon is an extinct North American bird. The species lived in enormous migratory flocks until the early 20th century, when continued hunting and habitat destruction led to its demise.

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An organism having more than two sets of homologous chromosomes is known as polyploid and the phenomenon of having them is called polyploidy. Polyploidy refers to a numerical change in a whole set of chromosomes. Polyploidy may occur due to abnormal cell division, either during mitosis, or commonly during metaphase-I in meiosis.

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Animals that ingest bulk food unavoidably take in some matter that they are incapable of using. Substances that cannot be digested, such as cellulose, pass into the colon, or large intestine. Egestion is the passing out of undigested food as faeces, through the anus.

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Metamorphosis is a process by which animals undergo extreme, rapid physical changes some time after birth. Commonly known examples of metamorphosis include the process undergone by most insects, and the transformation of tadpoles into frogs. Hormones called molting and juvenile hormones, which are not species specific, apparently regulate the changes.

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G. Haberlandt, a German botanist, in 1902 cultured fully differentiated plant cells isolated from different plants. This was the very first step for the beginning of plant cell and tissue culture. Further contributions were made by the Cell Doctrine which admitted that a cell is capable of showing totipotency. In India, the credit for detailed working on tissue culture goes to P. maheshwari.

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A goitre, or goiter, is a swelling in the neck resulting from an enlarged thyroid gland. A goitre can be associated with a thyroid that is not functioning properly. Worldwide, over 90% of goitre cases are caused by iodine deficiency. The term is from the Latin gutturia, meaning throat.