Biology MCQs

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The Leydig cells which are found in the human body are the secretory source of Androgens.

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An improperly functioning immune system, alcohol, medicines, and viruses can cause hepatitis. This is a viral disease, that causes hepatic anorexia resulting in liver damage or jaundice.

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Applications of rDNA technology are:
1. Development of Transgenic Plants
2. Production of Antibiotics
3. Production of Hormone Insulin
4. Production of Vaccines
5. Production of Interferon

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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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Crown gall is a disease caused by the bacterium Agrobacterium tumefaciens (synonym Rhizobium radiobacter), which enters the plant through wounds in roots or stems and stimulates the plant tissues to grow in a disorganized way, producing swollen galls. As the disease progresses, plants lose vigour and may eventually die. In science of Biotechnology, it is considered as natural engineer.

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Mycoplasma is a genus of bacteria that lacks a cell wall around their cell membrane. Without a cell wall, they are unaffected by many common antibiotics such as penicillin or other beta-lactam antibiotics that target cell wall synthesis. In comparison to other prokaryotes, they are consequently placed in a separate class Mollicutes(mollis, soft; cutis, skin).

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Cause of night blindness is a deficiency of retinol, or vitamin A, found in fish oils, liver, dairy products, vegetable and fruits yellow in colour. Nyctalopia also called “Night Blindness” is a condition making it difficult or impossible to see in relatively dim light. To over come deficiency of vitamin-A, one needs to feed of food products rich in carotene which is used in synthesis of vitamin-A is liver.

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Influenza, commonly known as ‘the flu’, is an infectious disease caused by an influenza virus. There are 4 types of seasonal influenza viruses, types A, B, C and D. Influenza A and B viruses circulate and cause seasonal epidemics of disease.

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Crabs come from the same family as lobsters, crayfish, shrimp, krill and barnacles, as all are in the subphylum crustacea. They are also in the phylum Arthropoda, which includes insects, arachnids and crustaceans. They are decapods (having ten legs) and form an order within the decapods, called the Brachyura.

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Blue whales are the largest animals ever known to have lived on Earth. These magnificent marine mammals rule the oceans at up to 100 feet (30 meters) long and upwards of 200 tons (181 metric tons). Their tongues alone can weigh as much as an elephant. Their hearts, as much as an automobile. Blue whales reach these mind-boggling dimensions on a diet composed nearly exclusively of tiny shrimplike animals called krill. During certain times of the year, a single adult blue whale consumes about 4 tons (3.6 metric tons) of krill a day.