Biology MCQs

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An arthropod is an invertebrate animal having an exoskeleton, a segmented body, and paired jointed appendages. It is considered as the largest phylum in the animal kingdom with an estimated 85 percent of known species included in this phylum.

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Respiratory roots are found in aquatic plants and plants which grow on marshy areas. In mangroves the roots are not getting sufficient oxygen and hence they grow upwards from the ground.

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Please note that Bast Fibers are obtained from Phloem

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Smallpox was an infectious disease caused by one of two virus variants, Variola major and Variola minor. the World Health Organization (WHO) certified the global eradication of the disease in 1980.

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As per the WHO definition, within 42 days of the termination of pregnancy, the death of a woman is counted in the Maternal Mortality, irrespective of the duration and site of the pregnancy.

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Alveoli are tiny sacs in our lungs. The main function of the alveoli is the exchange of carbon dioxide for oxygen in the lungs.

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The Great Zebra, Lesser Zebra and Spotted Zebra are the swallowtail butterfly found in the Southeast Asia, which are relatively common and not threatened species.

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Blood is carried through the body by Blood Vessels. With the help of perfusion process capillaries supplies blood to the tissues. The diameter of capillary ranges from 5-10 micrometers. The diameter of arteriole is approximately 30 micrometer.

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Information from one neuron flows to another neuron across a synapse. The synapse contains a small gap separating neurons. The synapse consists of: a presynaptic ending that contains neurotransmitters, mitochondria and other cell organelles.

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Darwinism is a theory of biological evolution developed by the English naturalist Charles Darwin. All species of organisms arise and develop through the natural selection of small, inherited variations that increase the individual’s ability to compete, survive, and reproduce.
Darwin’s evolutionary theory of natural selection gave a more rational explanation of the formation of new species. As per natural selection, various species originated from a single species as a result of adaptation to the changing environment.
Natural selection takes place in four different ways as follows:
• Variation – The changes accumulated over a period of time in an organism usually gives rise to a new species.
• Inheritance – It is the passing on of the variations over generations which ultimately lead to speciation.
• A high rate of growth of population – This gives rise to more number of organisms being reproduced by a species than the environment can support which might lead to the extinction of that particular species.
• Differential survival and reproduction – The superior variations lead to survival of a particular organism and the inferior or negative variation leads to extinction. The superior variations are the ones inherited during reproduction.