2 0 2 0
B.Sc (IV Semester) Examination
BOTANY
Paper : BOT–241
( Plant Physiology )
Full Marks : 50
Pass Marks : 35%
Time : Two Hours
Note : 1. Attempt answers as per the instructions.
2. The figures in the margin indicate full marks for the questions.
I. State and explain any five of the following : 2×5=10
(a) Trace elements
(b) ATP
(c) CAM plants
(d) Vernalization
(e) Ethylene
(f) Osmotic pressure
(g) Cytochrome
(h) Respiratory quotient
II. Answer any four of the following questions : 5×4=20
(a) Describe various theories of cell permeability.
(b) Discuss the role of phosphorus and potassium in plants.
(c) Define photoperiodism. What is the significance of photoperiodism in plant life?
(d) Briefly explain active absorption of mineral salts.
(e) Define growth hormones. Describe the role of auxins in plant metabolism.
(f) Write a brief note on structure and function of phytochrome.
(g) What are macro- and micronutrients?
III. Answer any two of the following questions : 10×2=20
(a) Describe the mechanism of opening and closing of stomata.
(b) Explain C4 cycle and discuss its significance.
(c) Describe the mechanism of ascent of sap in plants.
(d) Explain oxidative pentose phosphate pathway. What are the primary results of the pathway?
(e) What is seed dormancy? Discuss the factors that affect seed dormancy.
(f) Discuss the water absorption mechanisms in plant.
