Biology MCQs

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White blood cells (WBCs), also called leukocytes or leucocytes, are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from multipotent cells in the bone marrow known as hematopoietic stem cells.

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Jellyfish and sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the sub-phylum Medusozoa. Jellyfish do not have specialized systems for osmoregulation, respiration and circulation, and do not have a central nervous system.

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Dengue which is found in tropical and subtropical regions around the world is a mosquito borne disease and caused by a virus. Symptoms typically begin to appear three to fourteen days after infection.

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Flowering in long day plants is related to Gibberlin. Long-day plants usually flower when the night length falls below their critical photoperiod. Many of our summer blooming flowers and garden vegetables are long day plants.

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Enteric fermentation is a digestive process that takes place in the digestive systems of ruminant animals by which carbohydrates are broken down by microorganisms into simple molecules for absorption into the bloodstream of an animal.

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In Honey Bee the male itself dies after copulation.
sexual cannibalism is common in many families of spiders and scorpions

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Fraternal twins are also called as dizygotic twins. In this type of pregnancy two eggs are independently fertilized by two different sperm cells. These types of twins may be of the same or different sexes.

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Cleviceps purpurea is an important ascomycete that grows on the grains of rye grass cereals. It produces the drug ergot, which is both a severe poison and a useful medicinal drug. It affects the central nervous system as well as causes the contraction of involuntary muscle. Ergotism, caused by eating infected rye bread, was common in the Middle Ages, when it was known as “St. Anthony’s Fire.

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Rickets is a skeletal disorder that’s caused by a lack of vitamin D, calcium, or phosphate. These nutrients are important for the development of strong, healthy bones. People with rickets may have weak and soft bones, stunted growth, and, in severe cases, skeletal deformities.

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Homo habilis– He had a face similar to his ancestors. The skull and brain size indicate that he may have been able to speak. The earliest tools made were from this era. Homo habilis is known as the ‘handy man’ because he was the first to make and use tools.