General Science Questions (MCQs) for Competitive Examinations

Notes:
Claspers are organs found in male elasmobranchs. Each male has two claspers. They are located along the inner side of the shark or ray’s pelvic fin and are used in reproduction. During mating, the male deposits his sperm into the female’s cloaca (the opening that serves as the entrance to the uterus, intestine and urinary tract) via grooves that lie in the upper side of the claspers.

Notes:
The transition from dormancy to germination in seeds is a key physiological process during the lifecycle of plants. Abscisic acid (ABA) is the sole plant hormone known to maintain seed dormancy. It acts through a gene expression network involving the transcription factor Abscisic Acid Insensitive 3 (ABI3).

Notes:
Utricularia (also called bladderworts) is a genus of insectivorous plants. They occur in fresh water and wet soil as terrestrial or aquatic species. All Utri cularia are carnivorous and capture small organisms by means of bladder-like traps. Aquatic species feed on protozoa and rotifers swimming in water-saturated soil’ while terrestrial species feed on water fleas (Daphnia), nematodes and even fish fry, mosquito larvae and young tadpoles.

Notes:
Swedish naturalist Carlous Linnaeus established the binomial system of naming living organisms, setting a format and a structured process for classifying the interrelationships between plants (among which he included all fungi), and between animals. The binomial system that Linnaeus devised enables an author to refer to a species confident that it will mean the same thing to informed readers anywhere else in the world.

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:
Motor skills are needed to control the movements of the different muscles in the human body. The frontal lobe plays a large role in voluntary movement. It houses the primary motor cortex which regulates activities like walking. The frontal lobes are also involved in problem solving, spontaneity, memory, language, initiation, judgement, impulse control, etc.

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Black soil is most suitable for the cultivation of cotton. The deep and medium black lava soil of the Deccan and Malwa plateaus is considered ideal, though it can be grown on alluvial and red soil as well. The black cotton soil is also known as regur.

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Leukaemia is a type of cancer of the blood or bone marrow characterized by an abnormal increase of immature white blood cells called “blasts”. Damage to the bone marrow, by way of displacing the normal bone marrow cells with higher numbers of immature white blood cells, results in a lack of blood platelets, which are important in the blood clotting process. This means people with leukaemia may easily become bruised, bleed excessively, or develop pinprick bleeds (petechiae). White blood cells, which are involved in fighting pathogens, may be suppressed or dysfunctional. This could cause the patient’s immune system to be unable to fight off a simple infection or to start attacking other normal body cells.

Notes:
Liver produces bile which is stored in the gall bladder. Liver is the largest gland in the body. Bite contains bite pigments and bite salts i.e. sodium and potassium glycocholates.

Notes:
The ribs help in the expansion and contraction of the thoracic cavity (though that is primarily the function of the diaphragm). When we inhale, the ribs move up and outwards while the diaphragm moves down. An exact opposite movement occurs during exhalation when the ribs move down and inwards while the diaphragm moves up. The outward movement of the ribs during inhalation expands our chest cavity increasing the space to accommodate air that rushes to lungs, whereas the inward movement of the ribs helps the carbon dioxide filled the air to be pushed out of the lungs.