General Science Questions (MCQs) for Competitive Examinations

Notes:
Blubber is a thick layer of vascularized adipose tissue found under the skin particularly whales inhabiting of Arctic ocean. It’s presence insulate their body from ice cold. The energy stored in blubber includes both proteins (mostly collagen) and fats (mostly lipids). Blubber covers the entire body of animals such as seals, whales, and walruses—except for their fins, flippers, and flukes. Whaling largely targeted the collection of blubber: whalers rendered it into oil in try pots, or later, in vats on factory ships. The oil could serve in the manufacture of soap, leather, and cosmetics. Whale oil was used in candles as wax, and in oil lamps as fuel.

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Cyanobacteria, also known as blue green algae, are single-celled and belong to the family of Prokaryotes. That means, they do not have a well defined cell nucleus. The ability of cyanobacteria to perform oxygenic photosynthesis is thought to have converted the early reducing atmosphere into an oxidizing one, which dramatically changed the composition of life forms on Earth by stimulating biodiversity and leading to the near-extinction of oxygen-intolerant organisms.

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The masseter is located in the jaw and is one of the muscles of mastication or chewing. ? The bite strength of an average man is between 117 to 265 pounds. ? This ability to exert a force on an external object is an example of absolute strength.

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The open circulatory system is a system in which fluid in a cavity called the hemocoel bathes the organs directly with oxygen and nutrients and there is no distinction between blood and interstitial fluid; this combined fluid is called hemolymph. Arthropods and mollusks have an open circulatory system.

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The largest invertebrate is Mollusc. With over 80,000 species, molluscs form the second largest phylum of animals on Earth and range from tiny snails to giant squid and octopuses.

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The wings are modified forelimbs of birds which are the key to bird flight. Each wing is composed of three limb bones, the humerus, ulna and radius. Wings are much bigger than our arms, but being made mostly of feathers and hollow bones makes them very light. Their shape uses the wind to make flying easier.

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White blood cells (WBCs), also called leukocytes, are an important part of the immune system. These cells help fight infections by attacking bacteria, viruses, and germs that invade the body. White blood cells originate in the bone marrow, but circulate throughout the bloodstream. There are functionally two types of WBC, phagocytes and lymphocytes. Phagocytes engulf the germs and lymphocytes produce and release antibodies when required and as required by the body.

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Green undecomposed material used as manure is called green manure. It is obtained in two ways: by growing green manure crops or by collecting green leaf (along with twigs) from plants grown in wastelands, field bunds and forest.

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The blood sugar concentration or blood glucose level is the amount of glucose (sugar) present in the blood of a human or animal. The body naturally tightly regulates blood glucose levels as a part of metabolic homeostasis. The mean normal blood glucose level in humans is about 4 mM (4 m mol/L or 72 mg/dL, i.e. milligrams/decilitre); however, this level fluctuates throughout the day.

Notes:
The Venus flytrap (Dionaea muscipula) is a carnivorous plant native to subtropical
wetlands on the East Coast of the United States in North Carolina and South Carolina. It catches its prey chiefly insects and arachnids with a trapping structure formed by the terminal portion of each of the plant’s leaves, which is triggered by tiny hairs on their inner surfaces.