Biology MCQs

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The law of dominance is also called Mendel’s first law of inheritance. According to this, the hybrid offspring will only inherit the dominant trait in the phenotype.

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Anabaena is the nitrogen-fixing symbiotic organism present in Azolla. Anabaena is a genus of filamentous cyanobacteria that exist as plankton.

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A protein that provides structural support to a chromosome is called histone.

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Biofortification is the breeding crops to increase their nutritional value. This can be done either through conventional selective breeding or genetic engineering. Biofortification differs from ordinary fortification because it focuses on making plant foods more nutritious as the plants are growing, rather than having nutrients added to the foods when they are being processed.

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Feed cost is one of the important variable costs that plays a big role in determining the poultry cost. Variable costs rise and fall with the size of the output and the level of the operation. Fixed costs (for items such as taxes, insurance, interest, and depreciation on buildings and equipment), are incurred whether or not there is any output. Moreover the feed of broilers and layers varies with time of their growth.

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Microcytic anaemia: anemia characterized by small red blood cells, due to deficiency of iron; Pernicious anaemia: body does not make enough red blood cells due to lack of vitamin B12; Goitre: swelling of the neck or larynx resulting from iodine deficiency; and Pellagra: chronic lack of niacin (vitamin B3). It is also called 3-D disease.

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Evolutionary biologists classify tailbone as vestigial organs, or body parts that have become functionless due to evolution. It is perhaps the most commonly touted example in man of a “useless” evolutionary vestige. Also known as coccyx (because of its similarity to the shape of a cuckoo’s beak), tailbone is a vestigial tail left over from our tailed monkey- like ancestors.

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The sugar present in DNA is 2-deoxyribose, which is a pentose sugar. Deoxyribose is one of the three components of nucleotides, the building blocks of DNA. Each nucleotide consists of a phosphate group, a nitrogenous base—adenine (A), thymine (T), cytosine (C), or guanine (G)—and deoxyribose.

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Tusks are elongated, continuously growing front teeth, usually but not always in pairs, that protrude well beyond the mouth of certain mammal species. They are most commonly canines, as with warthogs, pig, and walruses, or, in the case of elephants, elongated incisors. The tusks are actually upper incisors, not canines. They are the only incisors the elephant has. Elephants, mastodons, and mammoths all have upper incisor teeth that emerge from the skull as tusks.

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Vitamin E refers to a group of eight fat-soluble compounds that include both tocopherols and tocotrienols. Numerous foods provide vitamin E. Nuts, seeds, and vegetable oils are among the best sources of alpha-tocopherol, and significant amounts are available in green leafy vegetables and fortified cereals.