Tips for ARS mains answer writing

You are supposed to answer 66 qns in 3 hrs i.e. 66 qns in 180 minutes

40 X 2 = 80 marks obj- in 20-25 minutes

20 X 5 =100 marks obj-in-95-100 minutes

6 X 10= 60 marks obj-in- 60 minutes

- time management is very very imp.

In your answer use bullets alongwith diagrams, figures.

Where steps or process is asked go for flow charts & steps format

Where ever application are asked - use recent examples & Research achievements

& go for bullets

Enrich your answers with sub-points & examples.

underline your example & relevant or main step or information.

For subjective type answer like

Scope of transgenic in crop improvement - go for articles & magazines & try to

make note of given examples & arguments (for & against)

Do Your home work

- Go for recent research examples & happening in ICAR & CSIR system relevant

to your field. This will also help your in your interview.

- Make your own handy note book related to your information updates, examples,

research findings & miscellaneous topics you consider as important. Revise this at

last moments of the exam (i.e. 3 days before the exam 3 times)

- Please do not revise outside the exam centre. Current in that your will head will

hinder the retrieval of the information stored in your long term memory.

Solved Answer sets

Set I

Set II

Set III

Set IV

Set V

Set VI

Set VII

Previous year questions unsolved

Set I

1. Electron microscope was discovered by M.Knoll & E.Ruska

2. Hall life of P32 is 14.5 days & C14 is 5570 yrs.

Hall life of P33 is 25.4 days & H3 is 12.46 yrs.

3. Phase contrast microscope was discovered by ______________ & used to

study _________ without ________________.

4. Dark ground microscope invented by _____________ & useful in the study

of _______________.

5. In monocots vascular bundles are absent & Cork Cambium is absent in

stem.

6. In prokaryotic DNA replication RNA primer is about ___________

nucleotides where as in Eukaryotes it is of ___________ nucleotides.

7. Size of okazaki fragments in Prokaryotes is 1000 nucleotides.

8. Fork movement rate in prokaryoles in 1000 bp/sec where as in eukaryots is

100 bp/sec.

9. Example of negatively charged aminoacid is Glutanic acid & Aspartic acid

with single word symbol __________ & ___________ respectively.

10. Phynylatanine, tyrorine & tryptophan are the three aromatic amino acids.

11. Arachidonic acid has 18 no. of carbons with double bonds at 9,12 & 15.

12. Tryptophan is converted to Anxin which in turn contributes to formation of

__________ & ___________.

13. Sphingo sine is derived from Ceramide.

14. Leucine & Lyrine are purely ketogenic aminoacids.

15. Pericentric inversion involve centromere.

16. Tertiary trisomic conditn is (2n+1+1) (2n+2, 2n+1+1, 2n+1+1+1)

17. Chemical formula of Colchicine is ________________.

18. Quasidiploid is ________________ (2n+1-1, 2n-2, 2n-1+1)

19. Mendel did not work in _________ but worked in _______________ Pisium

Sativum & Lamar king.

20. Jumping gene hypothesis was given by __________ in ____________.

21. Binzor gave concept of recan muton & cistron.

22. 5 Bromo-uracil & O6 methylguanive are the two example of base analoge.

23. Mutation was Ist discovered in Sheep (Encon) by seth wright & termed

cotned by Hug de Vries.

24. Meristem has high auxin content & have absence of Plasmodesmata.

25. For regeneration of Bt-cotton the variety used in tissue culture was Cocker.

26. Exposure of DNA to UV light leads to formation of Thymidine dimmers

(T=T).

27. Area under transgenic in India is 10.3 million lactave (5th rank)

28. Which one is more plymorphic SSR (SSR, SNP, AFLP, RAPD).

29. Most abundant marker is SNP (SSR, SNP, ALFP).

30. RAPD, ISSR uses single primer (True/False).

31. You may get poly morphosin without any variation in DNA deqnences

(True/False).

32. For determining copy number of a gene me can use Southern Blot & qPCR

techniques.

33. Define gene?

According to Singer and Berg in 1992. A gene is a combination of DNA sequence

that together constitute an expressible unit, whose expression leads to the

formation of one/more specific functional products that may be either RNA

molecule or polypeptide chain.

34. Define proteins & carbohydrates

Proteins are the polymers of amino acids linked by amide linkage [C11o-NH] having

N terminal (NH3) and C terminal (each) endo.

Carbohydrates are the hydrates of carbon or the compounds which give them upon

hydrolysin [CnH2] or polyhydroxy aldehyde/Kelones.

35. Av. Deight of an Amino acid is 110 Da

36. Cloning capacity of YAC, PAC, Cosmid, & PUC is 1000 Kb 300Kb 40Kb

& 4-5 Kb respectively.

37. YAC was developped by David Burke & BAC was developed by Melsimon.

38. Plitmus & PAT are examples of expression rectors.

39. Mito Chondria was discovered by __________ & is called Power house of

cell.

40. Enzymes act by lowering the activation energy of ryn.

5 Markers 20 Qns

1. How the cell cycle is regulated & controlled? Elucidate

Process of cell-growth and division is called cell-cycle. Cell phase involve - G1,

G2, S, and M phase.

Cell cycle is regulated various chekc points

mainly G1 - Check point

G2 - Check Point

M - Check Point

In G1 cdk levels are low, new pre RC complex not found and already found pre-

RC are activated for replication.

2. Write steps of Southern hybridization?

Destron sulphate used for enhancing hybridization.

Aried milk; hepanin; SOS prevent non-specific bending

3. How Enzymes catalyze reactions? What are allostearic Enzymes

Enzymes catalyze reactions by means of lowering the activation energy [Ea]

required to overcome the intermediate [ES] complex and form the product with out

being utilized in the ran.

Allosteric Enzymes: Enzymes which have an additional site called allosteric site

other than the acture site (bending to substrate) to catalyze the oxn.

Allosteric site (site for binding of effector molecules).

Activators (if molecule attachment enchances enzy. actinls)

Inhibitors (if reduces whibits)

Thereby effectors modulate the activity of allostrie enzymes eq. lac. repress of

lacoperon (allolactose inhisitor).

4. Compare & contrast between plant cell & prokaryotic cell?

Prokaryotic cell Plant Cell

At-cellular level:-

Nuclear material unbound as

naked.

cell-wall made of peptidoglycan.

organells absent

Mesosame as powerhouse 70s

Ribosomes

Genome Organization level

Intraw absent

No bound Histones

Genes are stacked and regulated

by a common promotes eq. lac

Bound as nucleus

Cell-wall made of cellular + hemi

cellulose

Present (eq. Milrechandius; er;

chloroplast etc).

Mitrchandria

80S Ribosames

Instrans present

Histones bound to proteins as

Nucleosomes

Censtacked genes.

Intergenic sequences and

operon

few retrotransposent/transposent

Insulators/Enhances absent

Functional level

Transcription and translation

simultaneously

Similarity

Heterotrophic except (Blue green

algaeycyanobactera)

retrotransposant, transposable

element at higher rate.

present

Separated by space. Transcription

in nucleus & translations in

cytoplasm.

Both perform the basic functions like replication; tran ripton, translations and

utilize energy in the form of ATP and are membrane bound. enclosed as cell.

6. On what levels the gene expression is regulated in Prokaryotes? Explain

Gene-expression in Prokaryolis is regulated at Transcription and Translation level.

At transcriptional level. Alongwith the RNA processing control initiation of

transcription of genes only when they are required depending upon the rate of

Metabolism, Response to environmental stress and cell-division.

7. Describe Lac openons give its mechanism of action? Explain with Diagram

Lac opiron is the Lactor metabolism system followed by Prokaryotes for caverting

lactose - glucox + galaclose (Energy sevrces)

(+ve) Regulation occurs when: [CAMP-CAP] binds to CAP site in Promoter and

activates/enhances adduct RNA Polymers to express lac Z, Y A glrus involved in

lactose metabolism.

Conditions

Glucose + ATP

CAMP

(-ve) Regulation Control

Lactox - Auolactole - Binds to lac Reprenor (Bound to promoler)

Conditions

Lactose present + Little amount of B-glutonidose

8. How will you generate a fine map rising marker for given 10 tns of the

chronisome?

Take divergent Parents 11x111

9. What is transposor tagging ? Explain

Determination of the region that is tagged by a Transposon in order words finding

the location of the region (DNA sequence) to which the transposon has been

integrated study of Inheritance and identification of the sequence tagged to

tranposon is important in Gene-isolation.

10. Write short notes on Paramutation?

Paramutation was the term used by R.A. Brink in 1950's.

Its involves the mutations that do not involve DNA sequence variation by variation

at histone modifications (Deacctylation/Methylation etc).

i.e. Justeraction b/w 2- alleles at a single locus, whereby one allile induces a

heritable change in other allile. The allile inducing the change is paramutagenic

while the allile that has been attered is called paramutant.

Since this change is meiotically inheritable, hence it violates mendels first low. A

paramutant allile may have an attered level of gene expression even though in the

segregating generation the paramutagenic allile is absent/gets separated from it.

Thus a single gene may result in spectrum of phenotypes. eq. r1 in maize from

completely colourlen to fully colored Kirquels.

In Maize paramutation seems to be RNA directed i.e. RNA directed DNa

mithylation carried by mop1 gene which is RNA dependent RNA polymerase

gene.

11. What is Chromosome walking chr jumping & chr. hoping? How they one

different

Chromosane walking: - When we have to find a gene out of the Candidate gems

and there is not much distance b/w the markus flanking the gene [Exonic region

mainly] then we head from the primers derived from market ends and reach to the

clone having both the marker end sequences same. The end of clone 1 derived

from one PCR act as primer sequence for other to generate clone2 and

subsequently.

Chromosane Jumping: - When we don't know where the gene is and probability of

large intrans/intergenic region or non-clonable gaps are there we go for chromosa

jumping

Genetic map is not saturated (condition) physical map not available.

Chromosome hoping:- When through chromosome jumping even we are not able

to reach to the gene, we go fs chromosome hoping where using translocation

stockes we hope into the gene, using sparse marker information.

Condition Sparse marker information

physical map unavailable.

12. What kind of Problems YACs suffer with? Give advantage of BACs over

YACs.

YaCs - Years artificial chromosames (David Burke in 1997) an imp cloning

cloning capacity - 1000Kb - 2000Kb eg. PYAC. Vector

TEL; CEN; ARS - Atonomously replicating sequences.

Problems

Chimeras are fsined [2 fragments from different regions.

Unitable and often incorporate in same.

Lead to deletions of Regions YAC.

Recombination is poorly understood thus YAC may integrate with yeast carasame.

Transformation is difficult

Maintainance is a problem.

Slow growing

Advantages of BAC's over YAC's

Easy to maintain and mainpulate

Chimiras not formed

CEN/TEL region not required

No delitions cloning capacity (250-300 Kb)

BAC- librarin created for sequening.

13. Describe process of replication in prokaryotes? How it is different from

Eukaryotes.

In Eukaryotes organisms there is replication origin as ARS intead of Oris in

Prokeyota.

No of Replicating regions in Enk. is many and in bidirectional bliay unlilee prok.

which show significance with Bidirectional movement.

Replication is initiated with DNA poly I with cere (L,E,Q) while in Eule, which is

(L, Q, E) which forms the core.

L, B, R, S) while DNA poly I, II, and (PCNA) as clamp loaden while Bclamp

Bsubmit.

14. What is translation? How it is regulated in Eukaryotes.

Translation:- Translation is the process in which cellular ribosanes create proteins.

It is an imp cap site part of gene expression i.e. mRNA produced by Binding trans

is decoded by a ribosame complex to produce a specific ammuni acid

chain/polypeptide which folds to fsm active protein.

Regulation of Translation in Eukahyotes:-

Initiation, Elongation and Termination factors

eIF4F process of scanning

eIF4F - eEF4E Binds to the 5'cap of mRNA

eEF4A - RNA helicase activity and removes secondary structure from mRNA

eEF4G Binds to eIF4E and PAB.

eIF4B - locates the first AUG site fs translation initiation

eIF3 - Ist factor bind to 4-S submit of Ribosame to facilitate subsequent steps

eIF2 - Facilitates binding of Met-tRNA met to 40S ribosamal subcent.

eIF5 - Promotes dissociation of all other IF's to carry out association 40S to 60S

eIF6 - Dissociation of inactive 80S ribosame into 60S & 40S

Elongation centrolled bf - eEFIL, eEF1B, r and eEFd

A codon on mRNA identifies a auti codar or trna (first genetic code)

15. Drawa fully featured structure of a Eukaryotic gene?

16. Elucidates different modes & methods of gene isolate? Give name & approches

of the method only.

Gene-isolation methods approach based. (Phentype to Genotype)

DDRT-PCR, SSH

Transcriptome sequencing

using next generation sequencing

454-Pysosequencing

Microarray (Hybridization based method)

SAGE - EST Clones (SAGE Tags)

Tlling;

forward genetics approach based (Genetype to phenotype)

MAP-based cloning

Insertional innitogeuesis

T-DNA nisestion

Transposen tagging

Retro transposan

Activation tagging

Positinal cloning based/Complementation tissuing

When gnome required we can use (PCR) and known primers to isolate gave.

17. What are molecular markers? What are its application in crop improvement.

Molecular markers are the differences in the nucliotide DNA at corresponding site

of the homologous chromosames which follow inheritance (mendelian) of patteus

(in case of nuclear DNA marker) and follow cytoplasmic/materul inheritance (in

case of organellar DNA markers).

Eq. SSR; RAPD; AFLP; SNP etc.

Applications of Molecular markers in trop improvement

Marker assisted selection:- Selection of plants with the desired gave at early stage

of growth can be done using inslecular marking date eq: MABC/MAR Sets

Selection of plants with heterozygons allelus at particular loci can be done.

Use of molecular markers in Map based cloning for isolation of gene eq. RFCP &

SSR.

DNA finger printing of Varieties for identification & characterization

Identification of cuttivars

Tagging of Gene using molecular markers. (Funcational marker eq. opaue 2 gene

using phiso)

Asessment of Genetic Diversity by random/specific markers. SSR marker

Gene introgression/QTL's DNA barcoding RAPD markers used

Detection and elimination of linkage drag. eq. finding donke recambinaty

Gene pyramiding Development of heterotic hybrids

eq. BLB and Blast re istance in Rice eq. Xa218X912 X95 genes.

18. What is PCR? What one its application

PCR is polymeose chain rxn (kavy mullis in 1985), in order words amplifical of a

target sequenc by mean of the primers (short oligo nucleotides) which bind to the

complementary sequence on the DNA and produce cycle number a large number

of topics of the largest sequence

Steps - Denaturalion (94oc fr Imin) dsna -ssona

nnealing (55-6ooc 1 min) 1 min/kb final limited

Erotension (720c fr 1 min) prime amended product camplion

19. What is site directed mutagenesis? What is its importance? Explain

Site directed mutagenesis:- An in-vitro method fs creating a specific mutation

in a known sequence and is typically performed by PCR based methods mainly.

Oligonucleotide Traditional PCR (An involvement of a mutated

directed mutagenesis Primer extension primer having insertion/deletion

Inverse PCR or substitution

Importance:-

It acts as a reliable tool for gene manipulations at a specific site.

Simple method for creating variation not tedious like earler techniques since it

utilize PCR.

It helps in study of gene structure and function as mutant proteins are fsmed.

In protein engineering to enhance enzyme specifically activity, affinity to

substrate, stability and mode of action improvement.

Enabled the codon biasing problem solvation which yielded better resulting

promoters in genetic engineering for transgenics formation

20 Describe EMP pathway? How it is regulate?

10 Markes - 6 Qns

1. What are transgenics? How there can help in crop improvement (a0 marks)

2. What are the various vectors used in Cloning? Describe

3. What is T-DNA tagging. Describe with example.

4. What is chloroplast transformation? What is its advantage & limitation

Chloroplast transformation refers to the transfer of gene of interest or entire gene

cassette through site specific recombination from chloroplast vector system to the

chloroplast gsame, resulting in Transformed chloroplast either by direct gene

dividery/biolistic gene approache/PEG mediated method.

Site specific recombination at IRASIRB. site with trnI and trnA of chlonoplast

vector constrceat (using Biolistic gene approach transfer occurs)

Advantages

No position effect (Hetero chranetization leading to gene silencing)

Trans gene containment (Pollen not a problem)

Higher expression (TSS) - greater than 40% protein produced

Site specific and single integration leading to multiple chloropl A transformalian

with entire Biochemical pathway inroduced eq. in carotenoids (Gene-stackery).

Post translational modification possible.

Better expression bacterial genes than nuclear

Disadvantages

High death rate and low regeneration frequency with Biolistic gud approach.

Multiple copy inserted at the same site, deletions it incorporated in DR side and

inverted side if then inversions occurs

Low expression of transgene if Eukaryster in prokeryothi system

Low transformation efficiency

regenration protocol stand required.

5. What is a genome? Describe Dangeros Dequencing what advantage

capillang based dangin sequecing has over traditions one.

Genome:- A complete set of chromosames that one prosent in a gametophytic

cell/ Haproid is called the genome, in order words denoted b n, For maize 2n=2o

and n=10. Is 10 linkage groups (10 chromosames) - comprise whole genome

Sangers sequencing:- Dideoxy termination sequencing method given by sanger

in 1977 used to sequence for the first time 5386 bp (0x174) phage. (M13 phage as

sequencing vector).

Dideoxy nucleotids having lack of 3'0 h group are nable to extend the growing

chain of the nuclotides, when a single strand with 5 ended primer label is extended

by addition of 3d NTP's + 1dd NTP. in each tube termination of nucleotide occurs

and many terminated sequences are obtained as laid in 4 lane get.

Hence that primer used is radiolabelled p32) and through autoradiophgh the

sequence is riad from the base of get to the upmost region. (Read sequences in

sanga method 500-800 bp)

Automation in sanger sequencing method lead to transfer gel based/slab

By fluoresence labelling

4 lane to single lane (Rather than primer labeled)

Capillary Electrophons has (50 mm) size of (Silicon capillary)

Automation single ddNTP moves is detected by CCD camera/photodiode

More precise detection and more no of sequences sequence daily.

Utilization of cycle sequencing method where through PCR based synthe of

template for sequencing da.

6. Which vector you will use for cloning fragments of human DNA & why?

What the advantage your vector of choice have over other one? Explain

SET - 2

1. Bacillus is the example of Naturaly competent micro organism.

2. Define Co incidence & Interference?

Coincidence is the frequency of occurence of a crossing over at positions 1 and 2.

While interference is the ability of an crossing over occuring at position 1 to

influence cross over at nearby postion 2.

either (+ve) or (-ve) influence.

Hence categorized as (+ve) interference or (-ve) interference

3. RFLP was the Ist marker developed in 1980 by Bostein et. al.

4. CAPS is Co-dominout (dominant/codominant) & also called PCR-RFLP.

5. 2% Crossing over = 1% recombination

6. SSRs are found due to Replication Slippage & Unequal crossing over.

7. TFIIH factor onwinds DNA at promoter during transcription in Eukaryotes.

8. TFIIB binds to TBP & recnts Pol II Tf II F Complex in Transcription.

9. DH Nils & RILs are examples of immortal mapping population.

10. Fullform of RAPD is Random aplification of polymophic DNA. & AFLP

Arbitaily fragment length polymupheno.

11. F2/Nils population are used for gene tagging.

12. Size of Tiplasmid is 23Kb & has cloning capacity of 750Kb.

13. pTIC58/Nopoline type Ti plasmid has T-DNA as Dingle transcriptioned unit

& Octopine pTiAcH5 has 2 Independent transcriptioned units.

14. Virc binds to overdrive region in Tiplasmid (Virc, Vird, Vir D2)

15. Vir D1 has Topo isomerase activity & Vir D2 was Endo nuclease activity in

Ti Plasmid transformation process.

16. Southern hybridization was given by E.M. Southern in 1975 & use _____%

Agarose.

17. Western bloting given by ___________ in ____________ yen.

18. Bollguard II has Crylac & Cryzab genes derived from Bt.

19. CRT & DREB one the two examples of Drought tolerant genes.

20. Cycloheximide blocks peptidyl transferase activity nor Eukaryotes.

21. Puronycin acts both in Pro & Eukoryotes & is derieved from mould

Streptomyces alboniger (T/F).

22. Teracycline blocks transcription while steptomycin is a Trisacchande

(disachande/Trisacchand) with binds to 30S submits (50S, 30S, 235)

23. Eukaryotes contains prokaryotic type DNA (true/false)

24. Replication involves RNA primers (true/false)

25. Ist aminoacide addition durint the protein synthesis uses ATP Energy.

26. There are 3 Elongation factors in Protein synthesis of Prokaryotes EF-T4

EF-TS & EF-G

27. Function of If1 is binds to A lite to inhibit binding of aminoacid tRNA at a

site in protein Dyn thesis.

28. Amber = UAG (UAA, UGA, UUA, UAG,)

Ochre = UAA

OPAL = UGA

29. What is polar nutation at one site like pranota results in unexpression of rest

of the genes downstream to the promoter region. Eq. lac gya gens unexpress

in lactor ope if nutation in promote site occurs.

30. C3 plants uses 3 ATP whereas C4 uses 5 ATPs per Glucose molecule.

31. Photorespiration was given by Working & _________.

32. End product of Glycolysis is pyrovate & has 1 3 & 10 as irreversible steps.

33. ___________ type of DNA is longest & __________ type is broadest.

34. Cellulose has __________ bonds where as amylose has ________ bonds.

35. Genome size of E. coli is 4.3 x 10 6 bp & Humans is 3.2 x 10 9 bp .

36. Lines refers to Longr interexpressed nuclear elements sines refers to short

interpressed nuclear element.

37. LK = Wr + TW

L- writs Twia

38. In meta phase stage 10,000 times packed.

39. Eight histones are - H2A H2B H3 H4 with H1 as the linker.

40. Eukayotic cells has type I topoi somerase but type Ii or DNA gyrase is

absent in them (T/F)

5 Marks

1. Elucidate the methods of SNP genotyping.

SNP genotyping methods

- SNP arrays [Hybridization based]

- Dot-blot

- Reverse dot blot

- Micro arrays

Direct sequencing based

overlap -BAC claves

Resequencing of short DNA structure

EST lcone

Enzyme based method

PCR RFLC; primer extension; SI nucleares

Oligo nucldid ligation & mapping of restriction invarus cleavage

2. What are the approaches of/genes for qualitative trauts? Briefly explain

3. Define MAS? What is its advantage & limitation?

Marker assisted selection:- It is a process of determining the location/heridite

of a trial from generate to generate it. It is process whereby a marker &

morpholyical. Brochemical; or DNA based) is used for indirection selecting the

genetic determinant of a traint of interest (disease raistane; productiveity trust

quality etc.

Advantages:- Early detection of GOI Hrangene intro grasim at seeding stage.

Heterzygotes identified

For recognize traits, identify the plant with derived alule and hence avoids selfing

for detective (time saving)/

Coa-effective and labour saving

No Biosafety issues

Not influenced by environment i.e. DNA based markers

No used to create artificial environment fs deletion

Disadvantage- Justial- investment is high.

4. What are the steps for construction of high density linkage map?

Steps involved are:- Selection of cantrasting parents 11 x 111

Divergent/Geographically distinct

Prepare cross

Generation of Mappign population

RILS, NILs, DH, F2; F2;3, BC

Size of population

Genotyping of the mapping population

5000 individual for fine mapping either from heterologoes

Identification of informative markers

Segregation studies

Avoid spurious linkage co-segregation b/w mankut tract the deed

(Statistical leos)

KOSambhi function

LOD score > 3

Assigning linkage groups to the chromosaves.

Construction of high density linkage map.

Note increasing the population size increase rare recombinant chances (2%

crossing over = 1% recabinet).

5) What are the steps of map based cloning? What are its advantage &

limitation.

Map based cloning

Identify that clone with both markers (M1 & M2)

that flank the GOI

prepare primers from marker and PCR. each PCR gives a clone

Select the clone with both the markers

Advantages

Direct PCT based method to land into In silvio approach

BIAST obtain possible candidate genes

Disadvantages

Not efficient for Long exams bearing genes with intronic sequences

What advantages caps marker have over RFLP

RFLP and CAPS both involve R.E digesters and Hybridization with probe to

identify the revied sequence