(a)How do the roots of vascular plants absorb water from the soil? [4]
(b)Discuss energy balance of respiration (ATP yield per molecule of glucose). [4]
(c)What are the physiological effects of ethylene on different plant species and plant organs. [4]
(d)Write a note on nature of enzymes. [4]
(20)
Q. 2
(a)Define Vernalization. Discuss the mechanism and factors necessary for vernalizations. [10]
(b)What is seed dormancy? How can seed dormancy be broken? Describe the practical significance of seed dormancy. [10]
(20)
Section II
Q. 3
(a)Discuss various types of erosion of soil by water. Describe the ways and means adopted by farmers to check water erosion. [10]
(b)Define water logging. How does it affect the plant growth? Discuss its causes and suggest also the measures for reclamation of water logged soils. [10]
(20)
Q. 4
(a)Give detailed account of grassland ecosystem and it's productivity. [10]
(b)Write note on any two of the following. A) Acid rain B) GlobalWarming C) Photochemical smog D) Eutrophication of aquatic eco-system [10]
(20)
Section III
Q. 5
(a)How does mitosis occur in plant cells. Explore the process in detail with diagrams. [10]
(b)Differentiate between the followings: i) mitosis and meiosis ii) Cytokinesis and karyokinesis [10]
(20)
Q. 6
(a)Describe the structure of plasma membrane in detail with diagrams. [10]
(b)Differentiate between followings i) hypertonic and hypotonic solution ii) Pinocytosis and phagocytosis iii) exocytosis and endocytosis iv) active transport and simple diffusion v) primary and secondary lysoso [10]
(20)
Section IV
Q. 7
(a)What are different types of RNA's? Discuss their structure and role in the process of translation. [10]
(b)Define mutation. Write a detailed note on the kinds of point mutation and also discuss causes of mutation. [10]
(20)
Q. 8
(a)What is meant by sex-linkage? Discuss the pattern of inheritance of X linked traits with some suitable examples. [10]
(b)Write short notes on the following: i) Barr bodies ll) Post transcriptlonal changes ln MRNA of eukaryotes: [10]
(20)
Section V
Q. 9
(a)What is Organic Evolution? How did the following contribute to Charles Darwin's formulation of the theory of natural selection? i) Uniformitarianism ii) Malthus essay on "Principles of population" [10]
(b)Write note on the followings: i) Neo-Darwlnism ii) Adaptive radlatlon [10]
(20)
Q. 10
(a)What is the theory of inheritance of acquired characteristics and how did Lamarck use it to explain the phenomenon of evolution? [10]
(b)What are the four assumptions of Hardy- weinberg law? How do the allelic frequency of population is changed? Explain with some suitable examples. [10]
The 2021 PMS Punjab Botany paper set by the PPSC. Question wording only; questions marked “Not yet checked” have not been compared with the official paper yet.
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