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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

ACIDS, BASES AND SALTS

ACIDS, BASES AND SALTS   INDICATORS        Indicators are some pigments or mixtures of pigments that are used to indicate the presence of acids and bases. Types of Indicators :                           1. Natural Indicators                          2. Synthetic indicators                          3. Olfactory indicators Natural indicators : Indicators that are derived from natural sources are called natural indicators. Examples of natural indicators are litmus, turmeric, red cabbage etc. Litmus : Litmus is a purple pigment derived from a plant called lichen. Litmus paper is available in two colors - blue and red. Blue litmus is used to test acid and red litmus is used to test base. Turmeric : Another such natural indicator is turmeric. Its color is yellow. Turmeric can only be used for testing bases. Turmeric turns reddish brown on contact with base. This does not change with exposure to acid. Red Cabbage : The color of the juice of red cabbage leaves is naturally purple. It turns gre