Biology MCQs

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A connecting link between reptiles and birds is Archaeopteryx. Archeopteryx had a complete set of teeth, a rather flat sternum, a long, ponytail, australis, and three claws on the wing.

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Bats and whales share mammary glands, placenta, and echolocation features. They both have developed the ability to use echolocation, a biological sonar for hunting.

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Usually, a decrease in the amount of oxygen in the blood will result in Cyanosis of the skin.

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A ligament is a small band of dense, white, fibrous elastic tissue.

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The weight of the human liver is 1.44 kg to 1.66 kg.

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Mycobacterium leprae is a bacillus (rod-shaped) bacterium that causes leprosy, also known as “Hansen’s disease”, which is a chronic infectious disease that damages the peripheral nerves and targets the skin, eyes, and muscles, upper respiratory tract, and nasal mucosa (lining of the nose).

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Animals that have a cavity between body wall and digestive tract are known as coelomates for e.g.. annelids, molluscs, arthropods, Echinodermata, and chordates etc. In contrast, animals in which the body cavity is absent are known as acoelomates. Platyhelminthes is an example of acoelomates. The presence or absence of body cavity or coelom plays a very important role in the classification of animals.

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“Animalcule” is a old term for a microorganism first used by Anton Van Leeuwenhoek means “small animal”. A paramecium is shaped somewhat like a slipper (a soft shoe), so it is called the slipper animalcule. Other better-known animalcules include: Amoeba, called Proteus animalcule etc.

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White blood cells (WBCs), also called leukocytes, are an important part of the immune system. These cells help fight infections by attacking bacteria, viruses, and germs that invade the body. White blood cells originate in the bone marrow, but circulate throughout the bloodstream. There are functionally two types of WBC, phagocytes and lymphocytes. Phagocytes engulf the germs and lymphocytes produce and release antibodies when required and as required by the body.

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Lactobacillus acidiphilous is used in milk curdling by producing lactic acid and reducing the pH of the milk. These bacteria convert the lactose into lactic acid, which imparts the sour taste to curd. It is a genus of Gram positive facultative anaerobic or microaerophilic rod-shaped bacteria.