LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – PLANT BIOLOGY & BIOTECHNOLOGY

AE 13

FIFTH SEMESTER – NOV 2006

PB 5506 – GENETICS AND PLANT BREEDING

 

 

Date & Time : 01-11-2006/9.00-12.00         Dept. No.                                                       Max. : 100 Marks

 

 

 

 

Part A                                           (20 marks)

Answer All questions

 

I Choose the Correct Answer                                                                     ( 5 x 1 = 5 marks)

 

01.The nucleic acid was first isolated from the nuclei of pus cells by

1. Freidrich Miesher b. W.T. Astbury
2. Wilkins d. F.G. Banting

 

2. The partial expression of both alleles in a heterozygote so that the phenotype is

intermediate between those of the two homozygotes is

1. dominance b. incomplete dominance
2. pleotropism d. independent assortment

 

3. Genetic code determines
4. constancy of morphological traits b. structural pattern of organism
5. sequence of aminoacids in a protein sequence of nucleotides in a protein

 

4. Which of the following represents Klinefelters syndrome ?
5. XX b. XO              c. XYY           d.  XXY

 

5. Mutation was proposed as a theory for the operative mechanism of evolution by
6. Charles Darwin b.  Louis Pasteur
7. Francisco Redi d.  Hugo de Vries

 

II State whether the following statements are  True or False    ( 5 x 1 = 5 marks)

6. Individuals with a dominant lethal gene die before they can reproduce.
7. The sequence of nucleotide bases in the mRNA is complementary to the template

DNA strand.

8. The regulatory gene of trp operon constitutively synthesizes a non- functional protein

called co- repressor.

9. Down syndrome is the result of twenty first chromosome present in three doses.
10. The cross between the parents belonging to two different species of the same genus

is called intraspecific hybridization.

 

 

 

 

III. Complete the following                                                                     ( 5 x 1 = 5 marks)

11. The condition in which one member of an allelic pair is manifested to the exclusion

of  the other——————-.

12     ________ enzymes are capable of catalyzing phosphodiester bond formation.

13    The __________ gene  marks the site at which transcription of mRNA  starts.

14     The second correction system  for correcting the occasional error missed by the

editing function is called _______ repair.

15     The use and disuse principle of evolution was proposed by _______.

 

1. Answer all, each in about 50 words ( 5 x 1 = 5 marks)

 

16. Define codominance.
17. Distinguish between A DNA and Z DNA.
18. What is poly A tail ?.
19. Write the mode of action of alkylating agents.
20. What is pureline selection ?.

 

PART B                                     ( 5 x 8 = 40 marks)

Answer any five, each within 350 words only. Draw diagrams and flowcharts wherever necessary.

 

21. What is quantitative inheritance? Briefly explain this with suitable example.
22. Describe the structure and organization of a gene.
23. Explain the structural organization of a chromosome.
24. Write a brief note on the features of genetic code.
25. Give a brief account on common defects in DNA and their origins.
26. What is klinefelter’s syndrome ?. Add a note on its symptoms and related findings.
27. Define mass selection. Briefly describe the procedure of mass selection and discuss

its merits and demerits.

28. Give a brief account of Darwin’s theory of natural selection.

 

 

PART C                                    ( 2 x 20 = 40 marks)

 

Answer the following, each within 1500 words only. Draw diagrams and flowcharts wherever necessary.

 

29. (a) Write an essay on sex determination in plants.

OR

(b)  i. Give an account of supercoiling of DNA.

1. Discuss :    ‘DNA is the genetic material’.

 

30. (a) Describe the following with suitable examples.
31. Genetic recombination using tetrad analysis.
32. Transposable elements in plants.

OR

(b)  Write an essay on different types of chromosomal aberrations.

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc.

IB 30

DEGREE EXAMINATION –PLANT BIOLOGY & PLANT BIO-TECH.

FIFTH SEMESTER – APRIL 2007

PB 5506 – GENETICS AND PLANT BREEDING

 

 

Date & Time: 02/05/2007 / 1:00 – 4:00          Dept. No.                                                     Max. : 100 Marks

 

 

Part A                                           (20 marks)

Answer All questions

 

I Choose the Correct Answer                                                                     ( 5 x 1 = 5 marks)

 

1. The scientist known for using X- rays to cause mutation is
2. T.H. Morgan b. H.J. Muller   c. Friedrich Miesher     d. D.E. Moore

 

2. Which one of the following is the smallest unit ?
3. recon    b.  muton          c. cistron          d. operon

 

3. In Coli according to operon theory an operator gene combines with
   1. regulator protein to “ switch on “ structural gene transcription.
   2. regulator protein to “ switch off “ structural gene transcription.
   3. regulator gene to “ switch off “ structural gene transcription.
   4. regulator gene to “ switch on “ structural gene transcription.

 

4. In the nuclei of the body cells of men and women most chromosomes are alike but they differ in number of X and Y chromosomes present. The nuclei of the body cells of men contain
5. two X chromosomes b. two Y chromosomes
6. one X and one Y chromosome d. one X and no Y chromosome

 

5. Mutation is very important for evolution to continue because mutation
   1. tends to bring equilibrium in a particular environment.
   2. triggers struggle for existence.
   3. causes recombination of genes.
6. produces new variations.

 

II State whether the following statements are  True or False    ( 5 x 1 = 5 marks)

6. If the test cross ratio of monohybrid cross is 1:1 (red : white) then the genotype

of the parent is Rr.

7. DNA has the ability to store genetic information, which can be expressed in the cell as needed.
8. Neurospora is suitable for genetic studies because it has very short life cycle.
9. Bromouracil is a base analogue mutagen.
10. Newer varieties developed by plant breeders are adapted only to selective areas.

 

 

III. Complete the following                                                                     ( 5 x 1 = 5 marks)

11. An offspring of two homozygous parents that differ from one another by only one

character is called——————-.

12. In ________ mechanism the synthesis of the new DNA strand is initiated from the

pre existing strand.

13. _______ inversion in which the rearrangement of genes is confined to single arm of

the chromosome

14. —————– introns are located in the protein encoding genes of the nucleus.
15. —————– discovered that new species arise as a result of natural selection.

 

1. Answer all, each in about 50 words ( 5 x 1 = 5 marks)
2. What is polygenic inheritance?
3. Distinguish between positive and negative supercoiling.
4. Define cistron.
5. What are intercalating agents?
6. Define heterosis.

 

PART B                       ( 5 x 8 = 40 marks)

Answer any five, each within 350 words only. Draw diagrams and flowcharts wherever necessary.

 

21. Write notes on
22. incomplete dominance
23. Lethal genes

• Multiple alleles

1. Back cross
2. Brief the events in semiconservative method of replication.
3. Give an account of post transcriptional modifications.
4. Describe the structure of a transposable element. Add a note on its functions.
5. What is Down’s syndrome? Mention its physical and physiological features.
6. What is point mutation? Mention its types and effects with examples.
7. Describe the procedure of hybridization in plant breeding.
8. Briefly explain the principles of Lamarckism.

 

PART C                       ( 2 x 20 = 40 marks)

Answer the following, each within 1500 words only. Draw diagrams and flowcharts wherever necessary.

29 a. Describe the following

1. Law of independent assortment
2. Cytoplasmic inheritance

(OR)

b.Describe in detail the structure and organization of DNA.

 

30 a.  With an example explain how gene expression can be regulated in E. Coli.

(OR)

1. Give a detailed account of DNA repair mechanisms.

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

ED 18

B.Sc. DEGREE EXAMINATION – PLANT BIOLOGY & PLANT BIO-TECH.

FIFTH SEMESTER – November 2008

PB 5506/ PB 4500 – GENETICS AND PLANT BREEDING

 

 

 

Date : 05-11-08                     Dept. No.                                        Max. : 100 Marks

Time : 9:00 – 12:00

PART – A                                                      (20 marks       

 

Answer ALL questions                                                                                              (5 x 1 = 5 marks)

 

1. Choose the correct answer.

 

1. A cross of the F₁ with the recessive parent is known as

1. a) Test cross b) back cross c) Single cross            d) double cross.

1. Hereditary variations in plant can be produced by

1. a) Auxins b) X-ray                       c) Kinetin                    d) Heat.

1. A co-ordinated unit which controls the genetic expression

1. a) cistron b) recon c) operon        d) muton

1. The thoery of inheritance of acquired characters was proposed by

1. a) Darwin b) Weisman c) Mendel                    d) Lamarck.

1. The process of mating of individuals which are more closely related than the average of the population to which they belong is called

1. a) In-breeding b) Hybridization          c) self breeding           d) Heterosis.

 

1. State whether the following statements are True or False (5 x 1 = 5 marks)

 

6. Continuous variations are attributed to crossing over.
7. In E.coli Lac operon is induced by lactose.
8. Gene mutation is caused due to change in sequence of nitrogen bases.
9. The monoallelic heterozygous plant producer only one gamet.
10. Devries theory of evolution is based on discontinuous variations.

 

III. Complete the following                                                                                  (5 x 1 = 5 marks)

 

1. Smallest unit which may cause mutation is ___________
2. Mutations in plants are induced by __________
3. Unit of distance between genes on the chromosome is _________
4. The F₂ phenotypic ratio for a dihybrid cross is _________
5. The term pureline was first introduced by _________

 

1. Answer ALL questions, each within 50 words (5 x 1 = 5 marks)

 

16. What is Heteroploidy?
17. Define termination codons
18. What is polygenic inheritance?
19. Define heterosis.
20. What is emasculation?

PART – B

Answer any FIVE each within 350 words.

Draw diagrams wherever necessary.                                                                     (5 X 8 = 40 marks)

 

1. Briefly describe the sex determination in plants.
2. Explain cytoplasmic inheritance with suitable example.
3. Write notes on the objectives of plant breeding.
4. Describe the pureline selection.
5. Briefly explain the principles of Lamarckism.
6. Discuss about klinfelters syndrome.
7. Write notes on mutagens.
8. Give an account of post transcriptional modifications.

 

PART – C

 

Answer the following each with in 1,500 words.

Draw diagrams wherever necessary.                                                                           (2 x 20 = 40 marks)

 

1.  a) Write an essay on chromosomal aberrations.

(OR)

1. b) Explain in detail the strucure and organization of DNA.

 

30. a) Explain how gene expression can be regulated in E.Coli with suitable example.

(OR)

1. b) Explain the following

(i) Transposable elements

(ii) Lethal genes

(iii) Hybridization.

 

 

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     LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – PLANT BIOLOGY & PLANT BIO-TECH.

VE 19

FIFTH SEMESTER – April 2009

PB 5506 – GENETICS AND PLANT BREEDING

 

 

 

Date & Time: 27/04/2009 / 1:00 – 4:00  Dept. No.                                                  Max. : 100 Marks

 

 

PART – A

1. CHOOSE THE CORRECT ANSWER: 5 x 1 = 5           

 

1. Eye colour in Drosophila is an Example of
2. Multiple allele Lethal gene c. Epistatic gene          d. Supplementary gene
3. This is formed when breaks occur in 2 chromosomes, simultaneously, & the broken chromosomes rejoin in a new manner,
4. Inversion Translocation                      c. Replication  d. Duplication
5. The smallest unit of recombination is
6. Muton cistron         c. Recon          d. operon
7. Pureline selection was 1^st developed by
8. Nilsson Bruce           c. Shull             d. Johannsen
9. Translation occurs at the
10. Ribosomes Mesosomes c. Dictyosomes d.Glyoxysomes

 

1. STATE WHETHER THE FOLLOWING STATEMENTS ARE TRUE OR FALSE: 5 x 1 = 5        

 

6. Plasma genes are present in the cytoplasm & transmit characters from one generation to another.
7. Genetic exchange in Eukaryotes occurs by Transformation Transduction & conjugation.
8. Klienfelter’s syndrome is genotypically and phenotypically male but bears many female characters.
9. Nonsense codons are those for which there are no aminoacids.
10. Down’s syndrome is also known as Mongolism.

 

• COMPLETE THE FOLLOWING: 5 x 1 = 5           

 

11. ____________ is a cluster of genes coding for a series of enzymes that work in an integrated biochemical pathway.
12. In Transcription the information in the DNA is transferred to ______________.
13. The smallest element, alteration of which can be effective in causing mutation is called ___________.
14. The basic unit of DNA molecule is _____________.
15. Post replicative repair mechanism, that may or may not involve rec A is termed _________ repair.

 

 

1. ANSWER ALL, EACH IN ABOUT 50 WORDS: 5 x 1 = 5         

 

16. What are Alleles.
17. Mention the law of Independent Assortment
18. Define Heterosis.
19. What are Lethel genes.
20. Define Codominance.

PART – B

ANSWER ANY 5, EACH WITHIN 350 WORDS ONLY:                                  5 x 8 = 40 Marks

 

21. Write down the conservative method of Replication.
22. Explain point Mutation.
23. Explain Darwinism.
24. What is Mismatch repair.
25. Explain clonal selection.
26. Write down the centres of diversity and the origin of cultivated plants.
27. Explain sex determination in plants.
28. Write about Quantitative Inheritance.

PART – C

ANSWER THE FOLLOWING EACH IN 1500 WORDS:                     2 x 20 = 40 Marks

 

29. Describe the molecular structure of DNA.

(or)

Write about DNA repair mechanisms.

 

30. Explain the selection Methods in Plant Breeding – Mass and Pure line selection.

(or)

Write an essay on chromosomal aberrations.

 

 

 

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