76.Which of the following have not undergone much of a change during the process of evolution over millions of years ? 1. Crocodile 2. Cockroach 3. Horse

77.The metal ion involved in stomatal regulation in plants is

78.In which of the following cell organelles do photo and thermochemical reactions occur indifferent sites ?

79.Stem cuttings are commonly used for regrowing

80.Which of the following are involved in the making up of a DNA nucleotide ? 1. Phosphoric acid 2. Deoxyribose sugar 3. Nitrogenous base