Kerala PSC Botany Lecturer / Assistant Professor Original Solved Question Paper: 2003 Exam
(Question Paper Code: 250/2003)
Original solved question paper of Kerala PSC Botany Lecturer/Assistant Professor examination conducted by Kerala PSC (Kerala Public Service Commission) for the recruitment / appointment of Botany Lecturer/Assistant Professor in Government Colleges of Kerala under the Directorate of Collegiate Education, Trivandrum, Kerala. The test was conducted in the year 2003 and the Question Paper Code Number is 250/2003. All questions were in MCQ (Multiple Choice Questions) format. A detailed answer key with explanations is given at end of each set.
Part – 2/5 (Questions 21 – 40)
21. Pro-phage is:
a. DNA incorporated with the host DNA
b. DNA or RNA in the early stages of infection
c. DNA of bacterial cell before viral infection
d. DNA present is only an incomplete fragment
22. ‘Bars of Sanio’ are the crescent shaped bars of cellulose present:
a. Near the pits on tracheids of Gymnosperm wood
b. On the secondary wood of Angiosperms
c. On the tracheids of Pteridophytes
d. On the extensive periderm of Cycas wood
23. Bryophytes exhibit alternation of generation:
a. Homomorphic
b. Heteromorphic
c. Isomorphic
d. No definite change in life cycle
24. DNA sequences that suppress promoter activity are called:
a. Enhancers
b. Reporters
c. Responsive elements
d. Silencers
25. Synthetic seeds are produced by:
a. Encapsulation of somatic embryo with matrix for storing
b. Cryopreservation of somatic embryo for long storage
c. Preservation of seeds by covering with organic polymers
d. Encapsulation of normal seed with a resistant matrix
26. Virus free plants can be developed by:
a. Seed culture
b. Meristem culture
c. Embryo culture
d. Leaf culture
27. Scientist who first proposed the concept of binomial nomenclature:
a. Carlous Linnaeus
b. Bentham and Hooker
c. Caspard Bauhine
d. John Ray
28. A woody Pteridophyte:
a. Marsilia
b. Angiopteris
c. Ophioglossum
d. Equisetum
29. Systemic diseases are those that:
a. Spread to particular part of the plant body
b. Spread to the particular system of plant body
c. Spread to entire plant to varying extent
d. Spread from one plant to another plant
30. A hydrophytic Pteridophyte with dimorphic leaves:
a. Marselia
b. Salvinia
c. Ceraptopteris
d. Equisetum
31. Northern blotting is used for the identification of:
a. DNA
b. RNA and DNA
c. Protein
d. RNA
32. The term used for physical mapping and isolation of genes whose protein product is unknown
a. Forward genetics
b. Reverse genetics
c. Genetic mapping
d. Gene hopping
33. Cohesion theory of ascent of sap was proposed by:
a. J.C. Bose
b. F.G. Donnen
c. E. Munch
d. Dixon and Jolly
34. Over-dominance can be a possible reason for:
a. Lethality in mice
b. Hybrid vigour in maize
c. Dominant epistasis in summer squash
d. Infertility in man
35. In PAGE, bis-acrylamide is used as:
a. Catalyst for polymerization
b. A medium to stimulate molecular separation
c. For cross linking acrylamide chains
d. Chemical to make it a stabilizing medium
36. Proteinacious virus like particles that can encode mRNA and DNA
a. Viroids
b. Prions
c. Retroviruses
d. Cyanophages
37. Some enzymes present in the cell in constant amount regardless of its metabolic state:
a. Inducible enzyme
b. Competitive enzymes
c. Isoenzymes
d. Constitutive enzymes
38. Which plant is known as ‘Maiden hair tree’?
a. Ginkgo
b. Cyathia
c. Ephedra
d. Pinus
39. Phenotypic ratio 12 : 3 : 1 is due to:
a. Complementary gene interaction
b. Recessive epistasis
c. Supplementary gene interaction
d. Dominant epistasis
40. Repeated units of histones wrapped by DNA are termed as:
a. Nucleo proteins
b. Nucleolus
c. Nucleosomes
d. Nuclear histones
Kerala PSC Botany Lecture Exam 2003 Question Paper
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Answer Key and Explanations (set 2/5)
The answer key is prepared with best of my knowledge and all of them may not be correct. If you find any mistakes in my decision, you should point it out and it will be appreciated. Contact: Admin.
21. Ans. (a). DNA incorporated with the host DNA
22. Ans. (a). Near the pits on tracheids of Gymnosperm wood
23. Ans. (b). Heteromorphic
In Bryophytes, gametophytic plants and sporophytic plants are morphologically dissimilar. Unlike other plant groups, in Bryophytes, the gametophytic generation is the prominent generation, which is haploid and independent. The sporophytic generation is diploid and it is completely dependent on gametophytic generation for nutrition.
24. Ans. (d). Silencers
The repressor protein binds to the silencer sequence of the gene and thereby it prevents the downstream movement of RNA polymerase enzyme and thus inhibits transcription.
Enhancers: short regions in the DNA which will enhance the expression of downstream genes by binding to some proteins called activators.
25. Ans. (a). Encapsulation of somatic embryo with matrix for sorting
Matrix used for encapsulation of somatic embryo: sodium alginate, which is converted to calcium alginate during polymerization.
26. Ans. (b). Meristem culture
Meristem is usually virus free. The exact reason for the absence of viral particles in the apical meristem is not known. The possible reasons may be:
(a). Meristem is an undifferentiated tissue. The virus particles cannot survive in an undifferentiated tissue.
(b). Viral particles in plants usually transfer through phloem. The phloem is not developed in the meristem.
(c). High metabolic rate of meristematic cells prevent the activity of virus
(d). High concentration of auxin and cytokinin hormone in meristem may inhibit viral life cycle
27. Ans. (a). Carlous Linnaeus
Linnaeus is known as the “Father of Taxonomy”
Important publication of Linnaeus: Species Plantarum (1753)
Other publications of Linnaeus: Systema Naturae, Genera Plantarum and Philosophia Botanica
He introduced the binomial system of classification in his publication Species plantarum in 1753
Linnaeus is the TYPE specimen for the scientific name: Homo sapiens (human)
28. Ans. (b). Angiopteris
29. Ans. (c). Spread to entire plant to varying extent
30. Ans. (b). Salvinia
Salvinia is a rootless plant; the root like organ seen in the plant is one of the highly dissected roots like leaf.
31. Ans. (d). RNA
Southern blot: detection of DNA
Northern blot: detection of RNA
Western blot: detection of Protein
Eastern blot: for studying post translational modifications of proteins
Far-Eastern blot: separation and detection of lipids
Far-Western blot: for studying protein-protein interaction
North-Western blot: for studying the interaction between RNA and protein
32. The question is confusing, the answer may be forward genetics or gene mapping
33. Ans. (d). Dixon and Jolly
34. Ans. (b). Hybrid vigour in maize
Hybrid vigour: the superiority of F1 hybrid over both of its parents. The phenomenon of hybrid vigours is explained by two theories. (a). Dominance hypothesis and (b). Over dominance hypothesis.
35. Ans. (c). For cross linking acrylamide chains
Components of PAGE and its role
Acrylamide: forms the matrix of the gel
Bis-acrylamide: the cross linking agent which forms cross links with acrylamide
Ammonium persulfate (APS): source of free radicals which initiate cross linking
TEMED: a stabilizing agent, stabilize free radicles to facilitate polymerization
Sodium Dodecyl Sulfate: a strong anionic detergent for denaturing the protein
36. The question is confusing, the suitable answer is Prions. However, prions do not code for RNA or DNA
Viroid: smallest infective particle with genetic material consists of short, circular and single stranded RNA molecule without a protein coat. Viroids are usually plant pathogens.
Prions: protenaceous infectious agents without a nucleic acid genetic material.
Cyanophage: a virus (phage) that infects cyanobacteria (blue-green algae)
Retrovirus: a category of virus with RNA as the genetic material and they replicate through a DNA intermediate with a special class of polymerase enzyme called reverse transcriptase.
37. Ans. (d). Constitutive enzyme
Inducible enzyme: enzyme produced only when there are specific stimuli
Isoenzymes: enzymes showing similar activity but with dissimilar amino acid sequence (structurally dissimilar enzymes doing similar functions, LDH is the best example)
38. Ans. (a). Ginkgo
Ginkgo is a living fossil
Maiden hair fern: Adiantum
39. Ans. (d). Dominant epistasis
40. Ans. (c). Nucleosomes
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