General Science Questions (MCQs) for Competitive Examinations

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Starfish carry out movements with the help of tube feet that are part of the water vascular system. Apart from their function in locomotion, the tube feet act as accessory gills. The water vascular system serves to transport oxygen from, and carbon dioxide to, the tube feet and also nutrients from the gut to the muscles involved in locomotion.

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Cod liver oil is the oil extracted from the livers of Atlantic cod. It is commonly taken as a dietary supplement and is packed full of nutrients. It is one of the best sources of omega 3 fatty acids (EPA and DHA), and it contains relatively high amounts of vitamin A and vitamin D. It is a vital nutrient for immune system function, cellular growth, eye health, and reproduction. It decreases blood clot formation and reduce inflammation in the body.

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Eccrine glands, sometimes called merocrine glands, are the major sweat glands of the human body. The specific function of sweat glands is to secrete water upon the surface so that it can cool the skin when it evaporates. The purpose of the glands on the palms and soles, however, is to keep these surfaces damp, to prevent flaking or hardening of the horny layer, and thus to maintain tactile sensibility. The eccrine gland opens out through the sweat pore.

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Fertilization is the process of fusion of the male and the female gametes. This can occur either inside (internal fertilization) or outside (external fertilization) the body of the female. Humans provide an example of the former whereas seahorse reproduction is an example of the latter.

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Anaemia is a condition that develops when blood lacks enough healthy red blood cells or haemoglobin. The three main types of Anaemia are due to blood loss, decreased red blood cell production, and increased red blood cell breakdown. Causes of decreased production include iron deficiency, a lack of vitamin B12, thalassemia, and a number of neoplasms of the bone marrow.

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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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Eutrophication is the ecosystem response to the addition of artificial or natural substances, such as nitrates and phosphates, through fertilizers or sewage. It leads not only to increased levels of nutrients, but increased Biological Oxygen Demand as well following the decay of algal bloom in stagnant water reservoirs.

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Plaster of Paris is a plaster made by calcining gypsum.
CaSO4•1/2?H2?O.
It can be used to impregnate gauze bandages to make a sculpting material called modroc. It is used to make classic plaster orthopedic casts to protect limbs with broken bones.

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Haemoglobin is oxygen-carrying pigment and predominant protein in the red blood cells. Haemoglobin is an iron-containing biomolecule. It is made up of four haem groups and globin. The haem groups contain iron atoms that can bind reversibly to oxygen molecules.

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The glomerulus functions as an excretory organ in hemichordates. Soluble wastes are collected from the blood by the glomerulus, lying within the proboscis cavity, and excreted from that cavity through a dorsal pore (an opening on the upper side) to the outside.