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Heredity and Evolution (Question Answer)

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  Heredity and Evolution (Question Answer) QUESTIONS 1. If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?  Answer: B trait has arisen earlier because it exists in maximum population. 2. How does the creation of variations in a species promote survival? Answer:  The variations created in a species protects the organism from extinction even in adverse conditions. As a result, the organism gains stability. Helps to adapt to the changing environment of the natural environment. 3. How do Mendel’s experiments show that traits may be dominant or recessive?  Answer:  Mendel used a number of contrasting visible characters of garden peas – round/wrinkled seeds, tall/short plants, white/violet flowers and so on. He took pea plants with different characteristics – a tall plant and a short plant, produced progeny from them, and calculated the percentages of tall or short pr
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Metals And Non-Metals

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Metals And Non-Metals  Metals Elements which are generally solid at room temperature and which forms positive ions by releasing electron from its outermost shell are called metals. Some examples of metal are- iron, copper, gold, mercury etc.  Physical Properties of metals 1. Lustre:  Metals, in their pure state, have a shining surface. This property is called metallic lustre. 2. Hardness: Metals are generally hard. The hardness varies from metal to metal. 3. Malleability: Metals can be beaten into thin sheets. This property is called malleability. Gold and silver are the most malleable metals. 4. Ductility: The ability of metals to be drawn into thin wires is called ductility. Gold is the most ductile metal. 5. Thermal and electrical conductivity:   Metals are good conductors of heat & electricity. The best conductors of heat are silver and copper. Lead and mercury are comparatively poor conductors of heat. 6. Melting Point: Metals have high melting points. 7. Colour: Metals are
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