The vaccine for smallpox was discovered by
Answer: C
Correct answer: Edward Jenner
Edward Jenner introduced smallpox vaccination in 1796, having observed that milkmaids who had caught cowpox did not take smallpox. The word vaccine comes from vacca, a cow. Smallpox is the only human disease to have been eradicated.
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Mushroom belongs to
Answer: C
Correct answer: Fungi
A mushroom is the fruiting body of a fungus: the organism itself is the network of hyphae in the soil or wood, and the mushroom is the structure it puts up to release spores. Fungi have no chlorophyll and absorb their nutrients.
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What helps in the rise of bread or dosa dough?
Answer: C
Correct answer: Growth of yeast cells
Dough rises because yeast in it ferments the sugars and releases carbon dioxide, which is trapped as bubbles in the gluten network. (In dosa batter the same job is done by wild yeasts and lactic acid bacteria, which also give it the sour taste.)
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Some plants have nitrogen-fixing bacteria in their root nodules. What are these bacteria called?
Answer: D
Correct answer: Rhizobium
Rhizobium is the nodule-forming symbiont of legumes. Azotobacter fixes nitrogen too, but free-living in the soil rather than in nodules; Nitrosomonas oxidises ammonia rather than fixing nitrogen.
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______ is used for the production of alcohol and wine.
Answer: A
Correct answer: Yeast
Yeast ferments sugars to ethanol and carbon dioxide without air. Wine uses the sugar of grapes, beer the sugar released from malted barley, and in each case the same organism does the work.
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Rhizobium bacteria
Answer: B
Correct answer: Help in nitrogen fixation
Rhizobium lives in legume root nodules and converts atmospheric N2 into ammonia the plant can use, receiving sugars in return. It causes no disease and has nothing to do with digestion.
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The parasite that causes malaria is carried by the
Answer: B
Correct answer: Female Anopheles Mosquito
Only the female mosquito bites, because she needs a blood meal to develop her eggs - the male feeds on nectar. The malaria parasite Plasmodium is carried by the female Anopheles; Aedes carries dengue and chikungunya.
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Rhizobium bacteria are present in the _____ of leguminous plants.
Answer: A
Correct answer: Roots
Rhizobium lives in nodules on the roots of legumes - peas, beans, gram, groundnut. The nodule is a structure the plant builds around the bacteria, and its pink colour comes from leghaemoglobin, which keeps oxygen away from the nitrogenase that oxygen would destroy.
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Some medicines obtained from micro-organisms are applied to kill or stop the growth of disease-causing microorganisms. Such medicines are called ______.
Answer: B
Correct answer: Antibiotics
Antibiotics are medicines obtained from microorganisms which kill or stop the growth of other, disease-causing microorganisms. Antibodies are proteins the body makes itself, and antiseptics are chemicals applied to surfaces and skin rather than taken as medicines.
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Chemicals produced by bacteria and fungi, and which treat infections caused by bacteria, are known as
Answer: B
Correct answer: antibiotics
Antibiotics are substances produced by microorganisms - moulds and soil bacteria - that kill or inhibit other microorganisms. Penicillin from Penicillium is the type case. They act on bacterial structures such as the cell wall and the 70S ribosome, which is why they are useless against viruses.
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