General Science Questions (MCQs) for Competitive Examinations

Notes:
Because of the screening effect, the net positive charge experienced by the electron from the nucleus is lowered and is known as effective nuclear charge. Effective nuclear charge experienced by the orbital decreases with increase of azimuthal quantum number(l).

Notes:
The petiole is the stalk-like structure which connects the leaf blade to the stem. The petiole has tiny tubes, that connect the veins on the leaf blade to the stem. Few of these enable water transport to the leaf while the other carry food away from the leaf to other parts of the plant.

Notes:
Coriander (Coriandrum sativum), also known as cilantro, Chinese parsley or dhania, is an annual herb in the family Apiaceae. All parts of the plant are edible, but the fresh leaves and the dried seeds are the parts most traditionally used in cooking.

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.

Notes:
The hair follicles have pigment cells that make melanin, a chemical that gives the hair its color. As one ages, these cells start to die. Without pigment, new hair strands grow in lighter and take on various shades of gray, silver, and eventually white.

Notes:
Land snails, insects, birds, and some reptiles excrete uric acid as the major nitrogenous waste. The white, crystalline substance seen in a typical bird or lizard “poop” is actually urine: a little pool of uric acid crystals in a very small amount of water.

Notes:
Abscisic acid also called plant stress hormone is responsible for responsible for dormancy of various types. It maintains dormancy in seeds and buds, stimulates the closing of stomata. Gibberellins are responsible for cell division and growth in cell size.

Notes:
The best way of getting rid of non-biodegradable waste such as plastic is by recycling them. Recycling is the process of converting waste materials into new materials and objects. The recovery of energy from waste materials is often included in this concept. Recycling is a key component of modern waste reduction and is the third component of the “Reduce, Reuse, and Recycle” waste hierarchy. Burning may release toxic gas into the atmosphere. Burying and dumping will hardly solve anything because of their very long life of self decomposition.

Notes:
Trypsin is an enzyme that helps us digest protein. In the small intestine, trypsin breaks down proteins, continuing the process of digestion that began in the stomach. It may also be referred to as a proteolytic enzyme, or proteinase. Trypsin is produced by the pancreas in an inactive form called trypsinogen. The trypsinogen enters the small intestine through the common bile duct and is converted to active trypsin.

Notes:
Mycobacterium leprae is a bacillus (rod-shaped) bacterium that causes leprosy, also known as “Hansen’s disease”, which is a chronic infectious disease that damages the peripheral nerves and targets the skin, eyes, and muscles, upper respiratory tract, and nasal mucosa (lining of the nose).