CSS Botany Past Paper 2020
PART-2(Subjective) 80 Marks
Attempt ONLY FOUR Questions from PART-II. (20×4)
PART-II
Q. No. 2 Discuss the life cycle of late blight of potato. Discuss its epidemics, disease forecast, and control.
Q. No. 3 Write a note on the sporophyte of Pinus. Compare the reproductive characteristics of Pinus with Selaginella.
Q. No. 4 Write down the discovery, chemical structure, and role of gibberellins in regulating various physiological processes in plants.
Q. No. 5 Describe the nitrogen cycle between the abiotic environment and organisms. Briefly describe how human activities have changed the global nitrogen budget.
Q. No. 6 How did Morgan and his students demonstrate that the gene was linked in fruit flies? How is linkage related to some events in meiosis?
Q. No. 7 Differentiate between plasmid and vector. Briefly explain the bacteriophage lambda (λ) vector. Describe its working and selection process.
Q. No. 8 Write comprehensive notes on any TWO of the following:
(a) The four components of taxonomy
(b) Distribution of gymnosperms in Pakistan
(c) Differences in the vascular system of stems of monocot and dicot plants