Biology MCQs

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Usually, color blindness is inherited as a recessive trait on the X chromosome. This is known in genetics as X-linked recessive inheritance.

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Restriction enzymes were discovered by Smith and Nathans. Proteins produced by bacteria that cleave DNA at specific sites along the molecule are called restriction enzymes.

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Flavr savr is a transgenic tomato variety that has a better shelf life and was the first GM food crop to be used commercially.

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Haemoglobin is called as tetrameric hemoprotein, while myoglobin is called monomeric protein. Haemoglobin is found systematically all over the body, while myo-globin is found in muscles tissues only. The body requires iron for the synthesis of its oxygen transport proteins, in particular hemo-globin and myoglobin.

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The small intestine, the part of the gastrointestinal tract between the stomach and the large intestine, is the main digester and absorber of food. The small intestine has three distinct regions – the duodenum, jejunum, and ileum–that carry out the absorption of nutrients and minerals from food. It converts the food into a semi-solid mass.

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Animals, such as mammals and birds, that maintain a constant body temperature regardless of the temperature of the surroundings are called warm blooded. These include birds and mammals. Whales are aquatic mammals hence, being mammal, they are warm blooded. The have a thick layer of fats called blubber underneath their skin to maintain temperature even in cold water of oceans.

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The best-known and most common chromosome abnormality in humans is Down’s syndrome, (Trisomy of 21st pair of chromosome). Down’s syndrome individuals also almost invariably develop Alzheimer’s disease, a form of dementia that is fairly common among the elderly people. People with Down’s syndrome develop this disease in their fourth or fifth decade of life, much sooner than other people. These people are also characterized by presence of webbed neck, Plamers crease, very broad forehead, round face and forked tongue.

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Humans are likely the most numerous species of mammal on Earth at the moment.

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Pulse, in botany, is a common name for members of the Fabaceae (Leguminosae), a large plant family. Pulses, high in protein, are used as food for humans and other animals. Besides, they play a key role in crop rotation due to their ability to fix nitrogen.

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Ossification is the process of laying down new bone material by cells called osteoblasts. It is synonymous with bone tissue formation. As per scientific evidence, by the age of 25 years nearly all bones are completely ossified in humans. Ossification test is a guess work based on the fusion of joints in the human body b/w birth and age 25. If all joints are fused the person must be of 25yrs of age or older.