General Science Questions (MCQs) for Competitive Examinations

Notes:
Human blood is red because hemoglobin, which is carried in the blood and functions to transport oxygen, is iron-rich and red in color. In its oxygenated state it is called oxyhemoglobin and is bright red. In the reduced state it is called deoxyhemoglobin and is purple-blue. Each hemoglobin molecule is made up of four heme groups surrounding a globin group. Heme contains iron and gives a red color to the molecule.

Notes:
The nephron is the basic structural and functional unit of the kidney. Its chief function is to regulate the concentration of water and soluble substances like sodium salts by filtering the blood, reabsorbing what is needed and excreting the rest as urine.

Notes:
White blood cells (WBCs) are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. They are also called leukocytes. WBCs are found throughout the body, including the blood and lymphatic system.

Notes:
The pituitary gland is a tiny organ, the size of a pea, found at the base of the brain. As the “master gland” of the body, it produces many hormones that travel throughout the body, directing certain processes or stimulating other glands to produce other hormones.

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Vegetable and fruits should be a part of our diet because they stimulate peristalsis. Dietary fiber found in whole fresh fruits and vegetables and whole grains stimulates peristalsis, flushing out fats and waste. Gas-producing foods like broccoli and cabbage also stimulate peristalsis. Drinking plenty of fluids is important because it keeps stools soft and easy to pass.

Notes:
The liver produces urea and other waste materials and then it pours it all in the right ventricle of the heart for oxygenation. The heart then distributes the blood to various parts of the body. So the impure blood brought by the Hepatic Vein and other blood vessels gets distributed through the aorta. This clearly indicates that hepatic vein from kidneys carries the largest amount of urea, while the renal vein from kidneys carries the least.

Notes:
The scientific name of peacock is Pavo Cristatus. It is also known as the Indian blue peafowl, common peafowl, blue peafowl, and blue Indian peafowl. It is a large and brightly coloured bird, is a species of peafowl native to the Indian subcontinent, but introduced in many other parts of the world.

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.

Notes:
Beriberi is a disease caused by a vitamin B1 (thiamine) deficiency. There are two types of the disease: wet beriberi and dry beriberi. Wet beriberi affects the heart and circulatory system. In extreme cases, wet beriberi can cause heart failure. Dry beriberi damages the nerves and can lead to a loss of muscle strength and eventually, muscle paralysis.

Notes:
Chloroplast, found in plant cells, is the site of photosynthesis in plants to prepare food(glucose) for the plant with the use of energy. It is a green plastid that contains chlorophylls A and B that absorb visible light energy and convert it to usable chemical energy in photosynthesis.