Home Preparation for National Talent Search Examination (NTSE)/ Olympiad
Chapter : 7. Heredity & Evolution
Environment and Inherited Traits
Environment : A change in environment brings about direct changes in plants. It produces new needs in animals. New needs (Doctrine of Desires), New need being about new desires that result in changes of older and formation of new organs. Use and Disuse of Organs, Repeated use of an organ makes it more complex and efficient. Non-use of an organ brings about its degeneration. Inheritance of Acquired Characters : The traits acquired by an individual during its life time are passed on to the next generation. After several generations the accumulation of changes results in the formation of new species. Inherited traits : Inherited traits are those characteristics which are passed from parents to their offspring, generation after generation because they are controlled by genes. There is also reshuffling of inherited variations during gemetogenesis and fertilization.