General Science Questions (MCQs) for Competitive Examinations

Notes:
Insectivorous plants are : Aldrovanda, Archaeamphora, Brocchinia, Byblis, Catopsis, Dionaea, Drosera, Genlisea, Hel iamphora, Nepenthes, Palaeoaldrovanda, Philcoxia, Roridule, Sarracenia, Stylidium, Triphyophyllum, Utricularia etc. In India, it was introduced by Dr. M. Swaminathan under the leadership of Pt. Nehru.

Notes:
‘Survival of the fittest’ is a phrase that originated from Darwinian evolutionary theory as a way of describing the mechanism of natural selection. Herbert Spencer first used the phrase, after reading Charles Darwin’s On the Origin of Species, in his Principles of Biology (1864), in which he drew parallels between his own economic theories and Dar-win’s biological ones.

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R.H. Whittaker (1969) proposed a Five Kingdom Classification: Monera, Protista, Fungi, Plantae and Animalia. The main criteria for classification used by him include cell structure, thallus organisation, mode of nutrition, reproduction and phylogenetic relationships.

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Bulbil is a small bulblike organ of vegetative reproduction growing in leaf axils or on flower stalks of plants such as the onion and tiger lily. It is a reproductive organ that takes part in vegetative reproduction. The bulbils drop from the parent plant on to the ground, give out adventitious roots and develop into new plants. The other structures involved in vegetative propagation include rhizome, bulb, corm, cuttings, etc.

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The uterus or womb is a major female hormone responsive reproductive sex organ of most mammals including humans. It is within the uterus that the fetus develops during gestation, usually developing completely in placental mammals such as humans and partially in marsupials such as kangaroos and opossums.

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Insect and bird wings are analogous structures but not homologous structures. They are externally similar in appearance and function (i.e. for flying), but have dissimilar origin and developmental plan.

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As per the report of WWF the ten most endangered rivers emerge as: the Salween, La Plata, Danube, Rio Grande, Ganges, Murray-Darling, Indus, Nile, Yangtze and Mekong.

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A goitre, or goiter, is a swelling in the neck resulting from an enlarged thyroid gland. A goitre can be associated with a thyroid that is not functioning properly. Worldwide, over 90% of goitre cases are caused by iodine deficiency. The term is from the Latin gutturia, meaning throat.

Notes:
The nucleoplasm is the liquid or semi-liquid substance of the nucleus filling the space around the DNA and the nucleoli. It is a type of protoplasm that is made up mostly of water, a mixture of various molecules, and dissolved ions. It is completely enclosed within the nuclear membrane or nuclear envelope.

Notes:
Pneumatophores are spongy erect roots extending above the surface of the water that facilitate the exchange of oxygen and carbon dioxide for the roots. They are specialized root structures that grow out from the water surface where inadequate oxygen required for normal respiration of the roots is present. They are seen in many mangrove species.