General Science Questions (MCQs) for Competitive Examinations

Notes:
A pulmonary artery is an artery in the pulmonary circulation that carries deoxygenated blood from the right side of the heart to the lungs. The pulmonary arteries are unique in that unlike most arteries which carry oxygenated blood to other parts of the body, the pulmonary arteries carry de-oxygenated blood to the lungs. After picking up oxygen, the oxygen rich blood is returned to the heart via the pulmonary veins.

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:
Phototropism is the growth of organisms in response to light. In plants, phototropism is a response to blue wavelengths of light and is caused by a redistribution of auxin from the illuminated side to the darker side of the shoot, resulting in quicker growth on the darker side and bending of the shoot toward the source of light.

Notes:
Femur (thighbone) the longest bone in human body. Its average length is 19.9 inch. The femur is the only bone in the thigh. Tibia (shin bone) and Fibula (lower leg) come next in sequence with length of 16.9 and 15.9 inch respectively.

Notes:
A fern is any one of a group of about 20,000 species of plants classified in the phylum or division Pteridophyta, also known as Filicophyta. Fern ally is a general term covering a somewhat diverse group of vascular plants that are not flowering plants (angiosperms) and not true ferns. Like ferns, these plants reproduce by shedding spores to initiate an alternation of generations. Both Ferns and fern allies belong to Pteridophytes.

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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.

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Detoxification is the physiological or medicinal removal of toxic substances from a living organism which is mainly carried out by the liver. It breaks down or transforms substances like ammonia, metabolic waste, drugs, alcohol and chemicals, so that they can be excreted. The liver filter is designed to remove toxic matter such as dead cells, microorganisms, chemicals, drugs and particulate debris from the bloodstream.

Notes:
Some plants have the stem branching out near the base. The stem is hard but not thick. Such plants are called shrubs. Eg: Rose plant. Shrubs have persistent woody stems above the field, unlike herbaceous plants. Shrubs may be evergreen or deciduous. By their numerous stems and shorter height, less than 6 m-10 m long, they are distinguished from trees.

Notes:
Mycoplasmas are the smallest and simplest prokaryotes capable of self-replication. Keeping the number of structural elements, metabolic pathways and components of the protein synthesizing machinery to an essential minimum places Mycoplasmas closest to the concept of ‘minimum cells’.

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Metamorphosis is a process by which animals undergo extreme, rapid physical changes some time after birth. Commonly known examples of metamorphosis include the process undergone by most insects, and the transformation of tadpoles into frogs. Hormones called molting and juvenile hormones, which are not species specific, apparently regulate the changes.