Biology MCQs

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Renin is released from juxtaglomerular (JG) cells when blood flow in the glomerulus decreases.

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The prostate gland is an accessory reproductive gland in male mammals. It is located just below the bladder in men.

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In Sporozoites form of Plasmodium enter the human body through the bite of infected female Anopheles mosquitoes.

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Parthenocarpy is the development of fruit without fertilization of seeds. In nature, parthenocarpy occurs as a mutation. Another biological mechanism stenospermacarpy also produces seedless fruits, but here the seeds are aborted while they are still small. In nature, parthenocarpy occurs as a mutation. Some plants require pollination or stimulation for parthenocarpy. This is known as stimulative parthenocarpy.

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Plant morphology or phytomorphology is the study of the physical form and external structure of plants. This is usually considered distinct from plant anatomy, which is the study of the internal structure of plants, especially at the microscopic level. It is useful in the visual identification of plants.

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Chameleons have specialized cells, chromatophores, which contain pigments in their cytoplasm, in three layers below their transparent outer skin. Dispersion of the pigment granules in the chromatophores sets the intensity of each color. Chromatophores contain pigments and reflect light, which are responsible for creating coloration. In chameleons, there are four types of chromatophores: xanthophores, erythrophores, iridiophores, and melanophores (Cooper and Greenberg, 1992).

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Oviparous is a zoological term that refers to animals that lay eggs which then hatch externally. Oviparous animals may fertilize their eggs either externally or internally. Frogs are oviparous since they lay eggs, which then develop outside of the mother. Ovoviviparous animals are relatively uncommon, sharks are most well-known.

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Human African trypanosomiasis, sleeping sickness, African lethargy, or Congo trypanosomiasis is a parasitic disease of people and animals, caused by protozoa of the species Trypanosoma brucei and transmitted by the tsetse fly. The tsetse fly is a large, brown, biting fly that serves as both a host and vector for the trypanosome parasites.

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Phytochrome is a photoreceptor, a pigment that plants use to detect light. It is a protein with a bilin chromophore. It detects mainly red and far-red region of the visible spectrum and regulates germination of seeds in photoblastic seeds.

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Tortoises generally have lifespans comparable with those of human beings, and some individuals are known to have lived longer than 150 years. Because of this, they symbolize longevity in some cultures, such as China. The oldest tortoise ever recorded, and one of the oldest individual animals ever recorded, was Tui Malila. It was presented to the Tongan royal family by the British explorer Captain Cook shortly after its birth in 1777.