General Science Questions (MCQs) for Competitive Examinations

Notes:
Alfred Bernhard Nobel was a Swedish chemist, engineer, inventor, businessman, and philanthropist. Atomic number 102 was named after him.

Notes:
A thick vein seen in the middle of the leaf is called the midrib. Pinnately veined leaves have one large central vein, called the midrib, which extends from the base of the blade to its tip. Other large veins branch off on each side of the midrib. The leaves of beech, birch, and elm trees have such a vein pattern.

Notes:
Calyptrogen is a layer of rapidly dividing cells at the tip of a plant root, from which the root cap is formed. It occurs in grasses and many other plants. The root cap is formed by several layers of cells that envelop the root tip externally. This covering of cells, of which the outermost ones are dead, envelops and protects the growing tip of root.

Notes:
The Gambusia fish, also known as larvivorous stagnant water fish. It feeds on the larvae of mosquitoes. So it helps in controlling their population. It is also called ‘mosquito fish’ and is being used as a biological control measure. Hence, a check on malaria and other vector borne diseases like even dengue.

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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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A typical adult human stomach will secrete about 1.5 liters of gastric acid daily. The best-known component of gastric juice is hydrochloric acid, the secretory product of the parietal, or oxyntic cell. It is known that the capacity of the stomach to secrete HCl is almost linearly related to parietal cell numbers.

Notes:
Smallpox was an infectious disease caused by either of two virus variants, Variola major and Variola minor. After vaccination campaigns throughout the 19th and 20th centuries, the WHO certified the global eradication of smallpox in 1979. Smallpox is one of two infectious diseases to have been eradicated, the other being Rinderpest.

Notes:
A carnivore is an organism that mostly eats meat, or the flesh of animals. Carnivores that eat herbivores are called secondary consumers, and large carnivores that eat other carnivores are called tertiary consumers. Animals and people who eat both animals and plants are called omnivores. Sometimes carnivores are also called predators.

Notes:
The mottling of dental enamel is an extremely common disorder, characterized by hypomineralization of tooth enamel caused by ingestion of excessive fluoride during enamel formation. It is also known as dental fluorosis. Common causes of fluorosis include: fluoridated drinking water (particularly during infancy), ingestion of fluoride toothpaste, use of fluoride tablets, and consumption of processed foods made with fluoridated water.

Notes:
Polar bears are supremely adapted to their environment – they have a number of traits that help them to cope with snow, ice, and below-freezing temperatures. They have a layer of fat that can be four inches (10 cm) thick. Although their fur is the primary source of insulation, the fat helps keep heat in as well.