subjetive model test paper

MODEL SUBJECTIVE TEST PAPER

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UNIT-16

1.

a. What is Ames Test? How it could be made applicable for eukaryotic systems.

b. Contrast and compare the mutagenic effect of demainating agent, base analogue and

Acridine dyes.

c. What do we mean by phrase “C-value Paradox”.

d. A human female with Turner syndrome also expresses the X-linked trait hemophilia, as did

her father. Which of her parents underwent non-disjunction during meiosis, giving rise to the

gamete responsible for the syndrome?

2.

a. Contrast the genetic composition of gametes derived from tetrads of inversion

heterozygotes where single crossing over occurs within a paracentric and pericentric

inversion.

b. If the recessive trait albinism (a) is present 1/10,000 individuals in a population at

equilibrium, calculate the frequency of

(i) the recessive mutant allele

(ii) the normal dominant allele

(iii) heterozygotes (carrier) in the population

(iv) mating between the heterozygotes

c. Explain the role of mutation in evolution

3.

a. Define inversion

b. How inversion causes mutation

c. Explain with diagram the types of gametes observed after single cross over between one

normal chromosome and other having paracentric inversion.

4.

a. Explain Hardy-Weinberg law

b. Consider the following data

p2 2pq q

2

(i) 0.25 0.50 0.25

(ii) 0.35 0.30 0.35

Among the following which data obeys Hardy-Weinberg law

c. 10 % population is suffering from PKU a recessive autosomal disorder. Find the proportion

of population who is carries of this disease.

5.

a. What is tautomeric shift in a purine of pyrimidines base?

b. Schematically explain how tautomeric shift in a base in DNA may lead to mutation


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UNIT-17

1.

a. When cows have twin calves of unlike sex (fraternal twins), the female twin is usually

sterile and has masculinized reproductive organs. This calf is referred to as a freemartin. In

cows, twins may share a common placenta and thus fetal circulation. Predict why a freemartin

develops.

b. Indicate the expected number of Barr bodies in interphase cells of the following individuals:

Klinefelter syndrome; Turner syndrome; and karyotypes 47,XYY, 47,XXX, and 48,XXXX.

c. In mice, the SRY gene is located on the Y chromosome very close to one of the

pseudoautosomal Regions(PAR) that pairs with the X chromosome during male meiosis.

Given this information, propose a model to explain the generation of unusual males who have

two X chromosomes.

d. For a species with a diploid number of 18, indicate how many chromosomes will be present

in the somatic nuclei of individuals who are haploid, triploid, tetraploid, trisomic, and

monosomic.

2.

a. Explain the mechanism of synthesis and transport of secretory proteins.

b. If 4 percent of a population in equilibrium expresses a recessive trait, what is probability

that the offsprings of two individuals who donot express the trait will express it?

c. What are polytene chromosomes? Where do they occur? What is cause of polytenization?.

3.

a. Explain role of MPF (Mitosis promoting factor) in control of cell cycle

c. Write a note on Nuclear Pore Complex.

c. Relate the potential effect of the Lyon hypothesis on the retina of a human female

heterozygous for the X-linked red-green color-blindness trait.

d. Contrast the evidence explaining the different modes of sex determination in Drosophila

and humans.

4.

a. Give reasons for

i. SRY+ XY male ii. SRY

- XY male iii. SRY

+ XX male

b. How are polytene chromosomes formed?

c. List the major applications of these chromosomes in cytogenetics and molecular Genetics


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TIME 50 Minutes

MM: 50

3+3+3+3=12

1. a. Explain the condition under which two species can co-exist in a single niche? Don’t

they reject competitive exclusion principle

b. Explain relationship between Biomass and productivity

c. Tiger is not eaten by other consumers. Give reasons

d. Explain adaptive radiation with example of Darwininian finches

2. a. Why productivity of blue green algae is low

3+3+3+3=12

b. Why do cyanobacteria dominate over green algae in eutrophic aquatic ecosystem.

c. Explain the succession in a water body with examples of flora and fauna of each

stage.

d. What would be effect on rate of succession in eutrophic lake

3. a. What is sustainable development?

3+3+3+3=12

b. What is need of Environment Impact Assessment?

c. Define food web? How it indicates stability of ecosystem?

d. Give examples of in-situ and Ex-situ modes of conservation.

4. a. What are liposomes?

2+3+3+3+3=14

b. What are applications of liposomes?

c. Differentiate signal transduction pathway for lipophilic and hydrophilic signals?


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d. Explain Different types of receptors involved in signal transduction?

e. Differentiate Diffusion and Facillated diffusion with example.


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UNIT-23

1.

a. Differentiate Necrosis and Apoptosis

b. Fas-FaL interaction between APC and Tc-Cell

c. Define Hypersenstivity and its types

d. Differentiate growth factor and survival factor

2.

a. Differentiate cell mediated and humoral immunity

b. Define clonal selection

c. Draw diagram of Ig G

d. Differentiate Idiotype and Allotype

3.

a. Explain hypotheses of allelic exclusion and clonal selection.

b. How are these interrelated?

UNIT-24

1. Define: 2 ½ X 4

(a) Km (b) Cooperativity

(c) Positive and negative cooperativity (d) Vmax

2. 2+3+5

a. Give example of competitive and non-competitive inhibitor

b. Explain regulation of enzyme action by covalent modification. Give 2 example

c. Explain kinetics of competitive and non competitive inhibition with the help of lineweaver-

burk plot.

3. 5+5

a. Label the marked places in given lineweaver-burk plot for enzymes

b. What are isoenzymes and abenzymes and what is their importance

3. Write a short note on: 3+3+4

a. Catalytic RNA.

b. Coenzymes with example


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c. What are the important characteristics of Active sites which are necessary to catalyze the

biological reaction.

4. Consider the following statements 2 ½ x 4

a. Judge the statements, whether they are true or false? Give reasons to support answer

a. Enzymes shifts the equilibrium

b. Enzymes decreases free energy of activation

c. Km is independent of substrate concentration

b. Treatment of carbonic anhydrase with higher concentration of metal chelator EDTA

(ethylene-diamine-tetra-acetic acid) results in loss of enzyme activity. Propose an explanation.

5.

a. The hydrolysis of pyrophosphate to orthophosphate is important in driving forward

biosynthetic reaction such as synthesis of DNA. The hydrolytic reaction is catalyzed in E. coli

by a pyrophosphatase that has a mass of 120 kd and consists of six identical subunits. For this

enzyme, a unit of activity is defined as the amount if enzyme that hydrolyzes 10 µmol of

pyrophosphate in 15 minutes at 370 C under standard assay conditions. The purified enzyme

has Vmax of 2800 units per milligram of enzyme.

i. How many moles of substrate are hydrolysed per second per milligram of enzyme when the

substrate concentration is much more than Km.

ii. How many moles of active sites are there in 1 mg of enzyme? Assume that each subunit has

one active site.

iii. What is turnover number of the enzyme?

6.

a. Explain the word ‘allosteric’.

b. Give two examples of allostearic effectors.

c. Can cooperativity occur in a single chain protein molecule? Discuss briefly.

UNIT-25

1. Short note

a. Hydrogen bonding

b. α – Helix (Sec. str. of protein)

c. 3-D structure of t-RNA

2.

a. demonstrate the following on the Ramchandran plot:

(i) Parallel and anti parallel β-sheets

(ii) Left handed and Right handed α-helix

3.

a. A hypothetical peptide gave on analysis the following data:

(i) The amino acid composition was 1 mole each tyrosine, lysine, Glutamic, serine

and Glycine and 2 moles of Leucine.

(ii) On tryptic digestion, it gave two peptides, one a dipeptide and another a

hexapeptide.


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(iii) On chymotryptic digestion also it gave a dipeptide and a hexapeptide

(iv) The N- and C-terminal amino acids were Ser and gly

(v) On CNBr cleavage, gave a tripeptide and a pentapeptide. The new N-terminal was

Glutamic acid. Suggest the amino acid sequence.

UNIT-26

1. 5+2

+3

a. What is yield of ATP when ATP when each of the following substrate is completely

oxidized to CO2 by a mammalian cell homogenate? Assume that glycolysis, the citric acid

cycle and oxidative phosphorylation are fully active.

a. Pyruvate b. Phosphoenol pyruvate

c. Lactate d. Fructose 1,6 bis phosphate

e. Dihydroxy acetone phosphate

b. What is Pasteur effect.

c. Explain the role of Phospho Fructo Kinase-1 in regulation of glycolysis.

2.

2+2+3+3

a. Name the key regulatory enzyme in Glycogenolysis and lipolysis.

b. Explain the role of c-AMP in regulation of Glycogenolysis and lipolysis.

c. How pyruvate is converted into phosphoenol pyruvate during gluconeogenesis. Explain

d. Why Gluconeogenesis from fatty acids is not possible in animals but possible on plants.

Explain.

3.

2+3+5

a. Write a balanced equation for the synthesis of tracyl glycerol, starting from glycerol and

fatty acids.

b. Glutamate is important neurotransmitter whose level must be carefully regulated in the

brain. Explain how a high concentration of ammonia might disrupt this regulation. How might

a high concentration of ammonia alter the citric acid cycle.

c. How activity of HMG CoA reductase is regulated during cholesterol synthesis.

4.

2+2+3+3

a. How sulpha drugs exterts their effect on bacteria. Why they do not effect humans.

b. What is mode of action of Methotrexate, an anti-cancerous drug.

c. Explain salvage pathway of purine metabolism.

d. What would be effect on nucleic acid metabolism if folic acid is not available in

mammalian cell. Explain.

5.


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a. The liver is the site of synthesis of plasma phospholipids and lipoproteins. Rats maintained

on a diet deficient in cholate often develop fat deposits in liver tissues. How could choline

deficiency be related to this aberration in lipid metabolism?

b. A student hypothesizes that 2 different enzymes E1 and E2

regulate these reactions in a cell. Is it possible ?

.

7.

a. The phosphorylation of glucose always takes place in the

presence of ATP. Why is it so?

b. In liver cell, the concentration of glucose is 5mM each. What

do you think will happen in absence of ATP under these conditions?

c. Why most of the biological reactions are kept away from equilibrium?

8.

a. Citric acid cycle does not involve the utilization of O2, but TCA does not take place in the

absence of O2. Why is it so?

b. Enoyl CoA isomerase deficiency will effect which metabolism? Butter or olive oil

metabolism?

c. How is GTP synthesized in TCA converted to cellular pool of ATP?

UNIT-28

1 2+5+3

In 1994, telomerase activity was discovered in human cancer cell lines. Although telomerase is not active in human somatic tissue, this discovery indicated that humans do contain the genes for telomerase proteins and telomerase RNA.

a. Since inappropriate activation of telomerase can cause cancer, why do you think the genes coding for this enzyme have been maintained in the human genome throughout evolution? Are there any types of human body cells where telomerase activation would be advantageous or even necessary? Explain.

b. How telomerase replication occurs? Explain

c. The genome of the fruit fly Drosophila melanogaster consists of approximately 1.6 X 108 base pairs. DNA synthesis occurs at a rate of 30 base pairs per second. In the early embryo the entire genome is replicated in five minutes. While DNA Polymerase can not add nucleotides at the rate more then 1000 nt per sec. Then How was this possible. Explain.

2. a Distinguish between (i) Unidirectional and bidirectional synthesis and (ii) Continuous and discontinuous synthesis. (iii) Conservative and Semi-conservative synthesis of DNA


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b. Suppose that E. coli synthesizes DNA at a rate of 100,000 nucleotides per minute and takes 40 minutes to replicate its chromosome. (i) How many base pairs are present in the entire E. coli chromosomes? (ii) What is the physical length of the chromosome in its helical configuration-that is, what is the circumference of the chromosome if it were opened into a circle? c. Several temperature-sensitive mutant strains of E. coli display various characteristics. Predict what enzyme or function is being affected by each mutation. (a) Newly synthesized DNA contains many mismatched base pairs. (b) Okazaki fragments accumulate, and DNA synthesis is never completed. (c) No initiation occurs. (d) Synthesis is very slow. (e) Supercoiled strands are found to remain following replication which is never completed.

UNIT-29 & 30

a. Explain the conrol of Tryphtophan operon of E. Coli by attenuation and anti-termination

sequences.

b. How they regulate gene expression in eukaryotes:

i. DNA methylation

ii. Transposition

a. What would be fate of trp operon when CASE (1) If repressor is unable to bind

tryptophan

CASE (2) If there is mutation on operator

CASE (3) If leader sequence is absent

b. Differentiate Transcription and Trans-activation

1.

a. How they regulate gene expression in eukaryotes:

i. Hetero chromatization

ii. Environment

10

2. For the genotypes and condition (lactose present or absent) shown in the accompanying

table, predict whether functional enzymes, nonfunctional enzymes, or no enzymes are made.

Genotype Condition Functional

Enzyme

Made

Nonfunctional

Enzyme

Made

No

Enzyme

Made

I+O

+Z

+ No lactose

I+O

cZ

+ Lactose

I-O

+Z

- No lactose

I-O

+Z

- Lactose

I-O

+Z

+/F’I

+ No lactose

I+O

cZ

+/F’O

+ Lactose

I+O

+Z

-/F’I

+O

+Z

+ Lactose


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I-O

+Z

-/F’I

+O

+Z

+ No lactose

IsO

+Z

+/F’O

+ No lactose

I+O

cZ

+/F’I

+O

+Z

+ Lactose

4.

3+3+4

a. Enlist various steps involved in RNA processing of m-RNA

b. What will happen of TATA box is absent as promoter sequence for eukaryotic gene.

c. Why DNA replication is performed in 5�3’ direction. What would have been problems if

DNA replication would have been 3’�5’. Explain

Unit-31 CANCER

1.

a. As a genetic counselor, you are asked to assess the risk for a couple who plans to have

children, but where there is a family history of retinoblastoma. In this case, both the husband

and wife are phenotypically normal, but the husband has a sister with familial retinoblastoma

in both eyes. What is the probability that this couple will have a child with retinoblastoma?

Are there any tests that you could recommend to help in this assessment?

2.

a. Review the stages of the cell cycle. What events occur in each of these stages? Which stage

is most variable in length?

b. Where are the major regulatory points in the cell cycle?

c. Progression through the cell cycle depends on the interaction of two types of regulatory

proteins, kinases and cyclins. List the functions of each, and describe how they interact with

each other to cause cells to move through the cell cycle.

5.

a. What is the difference between saying that cancer is inherited and saying that

predisposition to cancer is inherited?

b. Define tumor-suppressor genes. Why are most tumor suppressor genes expected to be

recessive?

7. Review the differences among transcriptional activity, tissue distribution, and function of

the tumor-suppressor genes associated with retinoblastoma and Wilms tumor. What

properties do they have in common? Which are most different?

8. Distinguish between oncogenes and protooncogenes. In what ways can protooncogenes be

converted to oncogenes?

9. How do translocations such as the Philadelphia chromosome lead to oncogenesis?

10. Given that 50 percent of all cancers are environmentally induced, and most of these are

caused by actions such as smoking, suntanning, and diet choices, how much of the money

spent on cancer research do you think should be devoted to research and education on the

prevention of cancer, rather than on finding a cure?


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11. The compound benzo[a]pyrene is found in cigarette smoke. This compound chemically

modifies guanine bases in DNA. Such abnormal bases are typically removed by an enzyme,

which hydrolyzes the base, leaving an apurinic site. If such a site is left unrepaired, an adenine

is preferentially inserted across from the apurinic site. In a study of lung cancer patients,

tumor cells from 15 out of 25 patients had a G to T transversion in the p53 gene, which has a

known role in cancer formation. Imagine that you are asked to testify as an expert witness in

the following court case: A widow of a man who died of lung cancer is suing R. J. Reynolds

for selling tobacco products that killed her husband (who was a life-long smoker). What do

you tell the jury?

12. Imagine you have identified a novel tumor suppressor gene. Describe a strategy by which

you will prove conclusively that this gene is involved in tumor suppression in vivo.

UNIT-32&33 Genetic Engineering

1.

a. What is role of restriction endonuclease in bacteria?

b. Lambda phage causes a plaque colony in a colony of E. coli but after mutation in lambda

phage it was not able to cause plaque in strain A of E. coli while in strain B it still formed the

plaque. Give reasons for differential behavior.

c. Give method of direct gene transfer in plants and animals

2.

a. What are characteristics of plasmid vectors

b. Name the promoters of prokaryotes

c. Name the expression promoter routinely used in prokaryotes and eukaryotes

d. Enlist the selection based antibiotics in prokaryotes and eukaryotes

3.

a. What is complementation of mutant alleles in bacteria?

b. How will you use complementation to find out the number of genes involved in a pathway?

4.

a. How could you clone a genomic DNA fragment greater than 60kb?

b. Describe the essential features of a YAC vector necessary for its existence in yeast.

c. What size DNA fragments could be cloned into these vectors and to obtain these fragments

d. what restriction enzymes should be used and why?

5.

a. Picogram of a plasmid DNA was used to transform E.coli by electroporation and 700

colonies were obtained. Calculate transformation frequency of the competent cells of E. coli

used in experiment.

b. A certain strain of E. coli could not be infected by many lambda phages tested. Give at least

2 possible reasons for this.

c. I wish to clone a repetitive sequence of DNA into a plasmid vector. What mutation in the

E.coli genome would ensure successful maintenance of this DNA sequence in E. coli.

d. A researcher wishes to increase sucrose biosynthesis in plants through genetic engineering.

Suggest a method.

e. What strategies can be used to engineer plants to produce biodegradable plastics?


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f. What are the four segments of DNA that typically comprise the plasmid genome.

6.

4+4+2+4

a. Differentiate genomic and c-DNA library

b. Differentiate topoisomerase I and II along with their functions

c. Name an inhibitor each for topoisomerase I and II.

d. when making c-DNA, the single stranded DNA produced by reverse transcriptase can be

made double stranded by treatment with DNA polymerase I. How ever no primer is required

with the DNA polymerase? Why is this?

UNIT-34 CELL CULTURE

a. Differentiate asymmetric hybrids and Cybrids.

b. Differentiate Gametoclonal variation and Somaclonal variation.

c. Differentiate electro fusion and electroportion.

d. Differentiate Androgenic and Gynogenic haploids.

UNIT-35

a. What is the major difference between endocytic and extracellular receptor?

b. Hydrophilic and hydrophobic signaling molecules

c. What are 2nd messengers? Name 5 in Eukaryotic signal transduction?

TIME 50 Minutes

MM:50

TEST

1.

4+4+2+2

a. As a genetic counselor, you are asked to assess the risk for a couple who plans to have

children, but where there is a family history of retinoblastoma. In this case, both the husband

and wife are phenotypically normal, but the husband has a sister with familial retinoblastoma

in both eyes. What is the probability that this couple will have a child with retinoblastoma?

Are there any tests that you could recommend to help in this assessment?

b. The compound benzo[a]pyrene is found in cigarette smoke. This compound chemically

modifies guanine bases in DNA. Such abnormal bases are typically removed by an enzyme,

which hydrolyzes the base, leaving an apurinic site. If such a site is left unrepaired, an adenine

is preferentially inserted across from the apurinic site. In a study of lung cancer patients,

tumor cells from 15 out of 25 patients had a G to T transversion in the p53 gene, which has a

known role in cancer formation. What is normal function of p53 gene and why there is a

cancer on mutation in this gene.

c. Name some chemical carcinogens?

d. Explain the term metastasis.

2

5+2+5


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a. Review the stages of the cell cycle. What events occur in each of these stages? Which stage

is most variable in length?

b. Where are the major regulatory points in the cell cycle?

c. Progression through the cell cycle depends on the interaction of two types of regulatory

proteins, kinases and cyclins. List the functions of each, and describe how they interact with

each other to cause cells to move through the cell cycle.

3.

3+3+3+3

a. What is role of restriction endonuclease in bacteria?

b. Lambda phage causes a plaque colony in a colony of E. coli but after mutation in lambda

phage it was not able to cause plaque in strain A of E. coli while in strain B it still formed the

plaque. Give reasons for differential behavior.

c. What are characteristics of an ideal cloning vehicle?

d. What is complementation of mutant alleles in bacteria? How will you use complementation

to find out the number of genes involved in a pathway?

TIME 50 Minutes TEST

MM:50

1. 2 X 5 =10

a. Give method of direct gene transfer in plants.

b. Name the expression promoter routinely used in prokaryotes and eukaryotes

c. Enlist the selection based antibiotics in prokaryotes and eukaryotes

d. How could you clone a genomic DNA fragment greater than 60kb?

e. Describe the essential features of a YAC vector necessary for its existence in yeast.

2. Write 2 X 8=

16

(i) the gene/protein responsible,

(ii) mode of inheritance

(iii) effect/symptoms of following genetic disorders

a. SCID b. Huntington chorea

c. Cystic fibrosis d. Duchene Muscular dystrophy

e. Lesch –Nyaan Syndrome f. Alzheimer disease

g. Phenyl keton Urea h. Sickle Cell Anemia

3.

3+3+2+2+2=12

a. Outline the steps involved in transferring glyphosate resistance to crop plants.


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b. What strategies can be used to avoid invasion of herbicide resistance trait from crop plants

to weeds so that weed may not become resistance to herbicides

c. What is Bt Cotton?

d. What do you mean by round up soybean

f. Which is best material to transfer novel gene in plants for production of transgenic plants

using tissue culture techniques? Explain.

4.

3+3+3+3=12

a. Why somatic embryogenesis is preferred over organogenesis in plant tissue culture

b. What are somaclonal variations? How they are important?

c. What are applications of Haploid cultures?

d. Differentiate asymmetric hybrids and Cybrids.

UNIT-36

1.

a. What are advantages of using florescence microscopy for visualizing cell.

b. Differentiate between TEM and SEM

b. How resolution of electron microscope can be enhanced

2.

a. Explain freeze fracturing and its utility in electron microscopy

b. Why phase contrast microscopy is preferred for studying live cells? Explain

c. Name any two flours used in microscopy. How they can make specific for any protein.

d. How resolution of light microscope can be enhanced

3.

a. Define resolution and magnification

b. Differentiate negative and positive staining

c. What is difference between the compound light microscope and the phase contrast

microscope?

d. What is the principle used in phase contrast microscope?

UNIT-37

1.

a. Explain partition cofficienct

b. How you can separate all m-RNA of cell for preparation of c-DNA library?

c. Often mobile phase used in chromatography is a mixture of two solvents. Why?

d. Differentiate Velocity and buoyant density centrifugation.


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2.

a. The absorption coefficient at 580 nm is 15,000 M-1cm-1. What is the absorbance of 1mg

ml-1 solution across the 1 cm-path?

b.. Which technique will you prefer to know the position of introns in eukarotic gene. Explain

with reasons

c. Define isoelectric point and electrofoccusing.

3.

a. Two proteins A and B of same molecular weight are mixed at pH 5.5. One of them get

denaturated at pH 8.5 and recoil at pH 5.5. How both of them can be separated

b. Why generally more then two solvents are used in TLC for separating solvents

4.

a. How you will separate the two proteins of mass 50,000 and 1 lakh Dalton using techniques

of column chromatography

b. Principle of ion exchange chromatography

c. Beads used in ion exchange chromatography

5.

a. A student accidently mixed 2 solutions to form a new solution containing 2 proteins of

similar densities (δ = 1.3 gm/cc) but different mol.weight ( 60KD & 190 KD) It also contained

2 types of sub cellular organelles not very different in size but differing in densities (δ=1.11

gm/cc and δ= 1.23 gm/cc respectively). Assuming that student has access only to ultra

centrifugation. What purification scheme should be planned to separate the four.

b. How will you find out if the 2 proteins are linked to each other by disulphide bridges using

any technique that you know.

UNIT- 38

1.

a. The quest to isolate an important disease causing organism was

successful and molecular biologists were hard at work. The

organism contained as its genetic material a remarkable nucleic

acid with a base composition of A= 20 % C= 29% G=29% and

U=21 %. When heated it showed a major hyperchromic effect and

when kinetics were studied, the nucleic acid of organism provided

the Cot curve shown next, in contrast to that phage T4 and E. coli.

T4 contains 105 nucleotide pairs and exhibits cot1/2 of 0.5. The

unknown organism produced Cot1/2 of 20. Analyze the

information carefully and give answers

2+4+4

i. What is genetic material in unknown organism

ii. What is complexity if genome of unknown organism

iii. What is nature of genome

7+3

2. Following reagents are often used in protein chemistry-

i. CNBr ii. Performic Acid iii. Phenyl isothiocynate

iv. Urea v. Dabsyl chloride vi. Chymotrypsin

Cot


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vii. Mercaptoethanol viii. 6 N HCl ix. Trypsin

x. Ninhydrin

Which one is the best suited for accomplishing of the following tasks?

1. Determination of amino acid sequence of small peptide-

2. Identification of amino terminal residue of a peptide (of which you have less than 0.1

µg).

3. Reversible denaturation of a protein devoid of disulphide bonds. Which additional

reagent would you need if disulphide bond is present

4. Cleavage of peptide bonds on the carboxyl side of aromatic side of aromatic residue

5. Cleavage of peptide bond on the carboxyl side of methione

6. Hydrolysis of peptide bond on the carboxyl side of lysine and arginine residue

b. Why Sangers dideoxy chain termination method is preferred over Maxim-Gilberts chemical

method.

3.

a. If an protein was

(i) treated with CNBR it yielded following fragments

try-arg-met

pro-gly-met

pro-lys-gly-arg

cys-phenyl ala-lys-met

(ii) treated with Trypsin it yielded

Gly-arg

Met-trp-arg

Met-pro-lys

Pro-gly-met-cys-phenyl ala-lys

Deduce the sequence of protein from N terminus to C terminus based on given data

b. Differentiate between Anchored PCR and Reverse PCR.

Q. 3 Following gel pattern was obtained after Sangers dideoxy chain termination method

ddA ddG ddC ddT

-------

-------

-------

-------

-------

-------

-------

-------

-------

a. What would be the sequence of DNA 2 ½ x4


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b. How this method of sequencing is better then Maxim Gilberts method.

c. Calculate the AT/GC ratio of the DNA sequence

d. What would be the sequence of RNA transcribed from this sequence

4. 3+3+4

a. What is hyper chromic effect and how it is measured?

b. What is Tm and how it is related to base composition?

c. What is Cot Curve and what is its application

5.

a. How would you distinguish three DNA molecules of same length having 60%, 40% and

20% GC content using UV spectroscopy?

b. Explain why a single stranded DNA has higher absorption in UV region compared to

double stranded DNA of same composition.

UNIT- 39

2 ½ X 4

a. Name the spectroscopy which can reveal the three dimensional structure of protein in

solution with reasons.

b. Which Atoms can utilize for NMR spectroscopy?

c. What are application of ESR

d. How circularly polarized light is produced in CD spectroscopy

2. 3+3+4

a. What is application of plasma emission spectroscopy?

b. What is the principle of X-ray crystallography?

c. Explain the principle of CD spectroscopy.

3.

a. How X-ray crystallography can be used for obtaining 3-D structure of proteins

b. Define Lamberts-Beer rule

c. What is fluorescence

d. What are application of plasma emission spectroscopy

e. Why the wavelength of emission is spectroscopy is always higher as compare to wavelength

of excitation.

UNIT-40

1.

a. What is the effect of radiations on organisms?

3+3+4

b. Can radiations prove beneficial for biological organisms? Explain

c. What is liquid scintillation counter? How can they make use of Cerenkov radiations for

measuring radiations from mixture of two radioisotopes?

2. Explain- 2 ½ x 4

a. Radiation Dosimeter


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b. Absorbed dose unit and Exposure units

c. Half life

d. Radio dating and commonly used radioisotopes for this purpose

a. Given the half life of 32

P and 14

C is nearly 15 days and 5000 years, respectively, what will

be the counts in both samples on day 30 and day 60 (expressed as % of zero day)?

b. What are tracer elements

3. Question 1X 10

1. Name some radioisotope which can be used to estimate the age of rocks

2. What is order of wavelength of X-rays

3. What is lamberts beer rule

4. What is advantage of NMR in deducing 3-D structure of protein

5. Which microscope will you use to study different events of mitosis

6. Name DNA sequencing method based on competitive termination of replication

7. Which microscopy uses ferritin tagged antibody

8. Which radioisotope is generally used to label DNA

9. Which pyrimidine analogue can be used to prove semi-conservative mode of

replication

10. Which technique is routinely used to study the genome of protozoa

subjetive model test paper

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