General Science Questions (MCQs) for Competitive Examinations

Notes:
Antibiotics are medicines used to treat a wide variety of infections or diseases caused by bacteria, such as respiratory tract infections (eg, pneumonia and whooping cough), urinary tract infections, skin infections and infected wounds. Antibiotics work by blocking vital processes in bacteria, killing the bacteria or stopping them from multiplying.

Notes:
Different fluids in the human body generally have a delicate range of acid-alkaline balance they maintain for optimal functioning. Human blood has a normal pH of about 7.41. The pH of urine has a wider range. Normal ranges for urine pH are from 4.5 to 8 and saliva has pH range of 6-8 to 7-0.

Notes:
Hydrogen peroxide (H2O2) is a water molecule with an extra oxygen atom hence, also called oxygenated water. It is very unstable and breaks down readily into water and a single oxygen molecule. So in nutshell, when Hydrogen peroxide readily loses active oxygen, Water is formed.
2H2O2 —> 2H2O + O2

Notes:
The National Institute of Mental Health and Nuro- Sciences is a premier medical institution located in Bengaluru, India. NIMHANS is the apex centre for mental health and neuroscience education in the country, the institute operates autonomously under the Ministry of Health and Family Welfare.

Notes:
Micropropagation is the practice of rapidly multiplying stock plant material to produce a large number of progeny plants, using modern plant tissue culture methods. It leads to the production of plants that are clones of each other. It often produces more robust plants, leading to accelerated growth compared to similar plants produced by conventional methods– like cuttings.

Notes:
Fertilization in plants is not directly influenced by sunlight. Fertilization occurs after pollination, when pollen grains land on the stigma of a flower of the same species. During this time, a series of events take place leading to the formation of seeds. However, none of these event is affected by presence or absence of light.

Notes:
The cerebellum is known as little brain. It is a region of the brain that plays an important role in motor control. i.e. in maintaining and coordinating body posture at different times of the day/night.

Notes:
The spleen is not an endocrine gland. This is because the spleen is not capable of aiding in the regulation of the hormone levels in the human body.

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Thrombin is a serine protease, an enzyme, that is at the centre of blood clotting process in human beings. It catalyzes the conversion of fibrinogen to fibrin and activates procoagulant factors V, VIII, XI, and XIII. Additionally, when bound to thrombo-modulin, it activates protein C, an anticoagulant zymogen.

Notes:
Root hairs are tubular-shaped tip-growing cells that arise from epidermal cells known as trichoblasts, behind the tips of young roots. Like all tip-growing cells, root hairs grow by the addition of cell wall precursors to the tip delivered by vesicles from the endomembrane system.