IGNOU BBYCT-137 December 2022 Previous Year Question Paper

Q1.(a) State whether the following statements are true or false : 5x4=2 @ As the root hair absorbs water from the soil, its diffusion pressure deficit (DPD) decreases. Gi) Plant contains more phosphorus than calcium.

(iii) Cobalt is readily mobile in the plant.

(iv) Some enzymes require additional factors which are called cofactors.

(b) Fill in the blanks : 1x3=

(3)

Q2.In CAM plants stomata are closed uring wee Gi) wee. enzyme converts Ne to NHs.

(ii) Most of the membranes are permeable

(c) Define the following terms : 1x5=5 G) Osmosis Gi) Stomatal frequency

(1) Vernalization

(iv) Long day plant

(v) Respiratory quotient

Q3.Describe the ‘Z’ scheme or zig-zag scheme of photosystem I and photosystem II working in tandem with well labelled diagram.

Q4.(a) Discuss the criteria of essentiality of a mineral nutrient. 3

(b) Define micronutrient and list any five micronutrients and discuss the role of any two micronutrients in plants.

Q5.Give a comparative account of Auxins, Gibberellins and Cytokinins.

Q6.Describe the reaction of Kreb’s cycle indicating the enzymes involved and sites of ATP synthesis with labelled schematic diagram.

Q7.What is photoperiodism ? How are plants classified on the basis of day length ? Discuss the importance of dark period in flowering plants.

Q8.(a) List the theories which are proposed to explain mechanism of phloem transport, and explain any one of them. 5

(b) What is biological stress ? List the various types of biological stress, and describe any one of them.

Q9.Write short notes on any two of the following : 5x2=10 @) Biological clock

(ii) Chemosynthesis

(iii) Structure of Chlorophyll-a

(iv) Lock and key hypothesis for enzyme action