51. In which phase of growth size of vacuole increases ?
A. Cell formation
B. Cell elongation
C. cell difterentiation
D. Cell transfer
Answer : Option B
52. What is the optimum temperature for growth of the plants ?
A. 25 to \(30^oC\)
B. 28 to \(30^oC\)
C. 0 to \(30^oC\)
D. 0 to \(28oC\)
Answer : Option B
53. Which apparatus is used for exact measuring of growth of plants in longitudinal axis ?
54. Growth regulators are chemically ........
55. From where auxin was isolated for the first time ?
A. Coleoptile of oat
B. Sperm cell of herring fish
C. Paddy plant
D. Human urine
Answer : Option D
56. Which of the following should be used for the control of weeds in farms ?
57. Which chemical induces formation of adventitious roots ?
58. \Which is incorrect for the effects of auxin ?
A. \(Induces^ +ve\) phototropism
B. Induces growth and length in stem
C. Shows apical dominance
D. \(nduces_ -ve\) phototropism in roots
Answer : Option B
59. Which of the following organic substance is growth inhibitor ?
60. From where indole acetic acid an organic substance was isolated for the first time ?