General Science Questions (MCQs) for Competitive Examinations

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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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Phototropism is the growth of organisms in response to light. In plants, phototropism is a response to blue wavelengths of light and is caused by a redistribution of auxin from the illuminated side to the darker side of the shoot, resulting in quicker growth on the darker side and bending of the shoot toward the source of light.

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Gambusia affinis, also known as Mosquito fish, is a species of freshwater fish that is introduced directly into ecosystems as a biocontrol to lower mosquito populations. The diet of this fish sometimes consists of large numbers of mosquito larvae. Gambusia affinis has turned out to be indispensable to modern Mosquito/Malaria control programs in countries such as Iran.

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Casein-Lactose protein-sugar pair is present in milk. Normal bovine milk contains 30-35 grams of protein per litre of which about 80 percent is arranged in casein micelles. Casein is present in milk, but it’s not a milk sugar like lactose. Instead, casein is one of the proteins found in milk. Unlike lactose, which causes an intolerance, these proteins in milk are what’s responsible for a milk allergy, according to Food Allergy and Research Education.

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Anatomy, a field in the biological sciences concerned with the identification and description of the body structures of living things. Gross anatomy involves the study of major body structures by dissection and observation and in its narrowest sense is concerned only with the human body.

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The aorta is the largest artery of the human body. It is an artery that directly arises from the heart itself and descends through the thorax and into the abdomen. All the arteries of the body, save the pulmonary arteries, stem from the aorta or one of its main branches.

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A vein is an elastic blood vessel that transports blood from various regions of the body to the heart. Veins are components of the cardiovascular system, which circulates blood to provide nutrients to the cells of the body. Veins can be categorized into four main types: pulmonary, systemic, superficial, and deep veins.

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Adamsia (Sea anemone), Pennatula (Sea-pen) are examples of Anthozoa Class under Coelenterata Phylum. The organism under this phylum are mostly marine, solitary or colonial, sessile, or free-swimming and radially symmetrical animals. Other examples of Anthozoa class are Meandrina (brain-coral), Fungia, Gorgonia (sea fan or horny coral), etc.

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Most of Earth’s oxygen comes from tiny ocean plants – called phytoplankton – that live near the water’s surface and drift with the currents. Like all plants, they photosynthesize – that is, they use sunlight and carbon dioxide to make food. Scientists believe that phytoplankton contribute between 50 to 85 percent of the oxygen in Earth’s atmosphere (National Geographic).

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As exercise commences pulmonary ventilation (breathing) increases in direct proportion to the intensity and metabolic needs of the exercise. During heavy exercise, breathing rate in an average adult person can increase upto 25 per minute.