eChapters

Plasmid is a double stranded, self replicating, circular extra chromosomal DNA of bacterium. It is used in recombinant DNA experiments to clone genes from other organisms and make large quantities of their DNA. Plasmid can be transferred between same species or between different species. The sizes of plasmids range from 1-1000 kbps. Plasmids are part of mobilomes (total of all mobile genetic elements in a genome) like transposons or prophages and are associated with conjugation.

This is a procedure for transforming bacterial cells with circular DNA plasmids containing an origin of autonomous DNA replication and a selective marker (antibiotic resistance). Logarithmically growing cells are made permeable to DNA by incubation in CaCl2 and the DNA is taken up from the surrounding buffer.

Enterobacteria phage ? is a bacterial virus, or bacteriophage, that infects the bacterial species Escherichia coli (E.coli). It was discovered by Esther Lederberg in 1950. The wild type of this virus has a temperate life cycle that allows it to either reside within the genome of its host through lysogeny or enter into a lytic phase, during which it kills and lyses the cell to produce offspring. Lambda strains, mutated at specific sites, are unable to lysogenize cells; instead, they grow and enter the lytic cycle after superinfecting an already lysogenized cell.

There are various methods available for isolation of high molecular weight genomic DNA from plants. The basic steps involved in all these methods are removal of cell wall, nuclear membrane, proteins, lipids, carbohydrates, cell debris, RNA without affecting the integrity of DNA. The two major factors that affect DNA integrity are action of endogenous nucleases and impact of mechanical shearing.

RNA is transcriptional product of DNA. The total RNA includes three classes, rRNA, tRNA and mRNA. The ribonucleic acids exists as ribonucleo protein particles in intact cells. The ribonucleo protein complex is dissociated by SDS in to RNA and protein deproutinised by phenol and the free RNA left in the aqueous solution is precipitated in cold by adding alcohol. 

Polysomes consist of two or more ribosome traversing a strand of mRNA, translating the nucleotide sequence into the corresponding amino acid sequence. Usually at any time, many ribosomes are translating an mRNA simultaneously forming a structure called a polyribosome or polysomes. One reason for isolating polyribosomes is to resolve them on sucrose gradients to determine the extent of ribosome loading. The second main reason is to provide a source of mRNA for in vitro translation.

DNA fragment to be used as a probe should be purified by gel electrophoresis. The band can be located after staining with ethidium bromide and electroeluted.

The in vitro radioactive labeling of DNA fragment is accomplished by the incorporation of a radioactive nucleotide during strand synthesis with Klenow enzyme (large subunit of DNA polymerase-I).

Nucleic acid hybridization requires denaturation i.e. the breakage of H-bridges between the complementary strands of the DNA either by heating at high temperatures or by treatment with denaturing chemicals like formamide. The restricted DNA, therefore, is denatured before transfer from the gel onto synthetic membrane since only single stranded DNA binds to nitrocellulose.

Exchange of genetic material rarely occurs between unreleated organisms and even similar species may not exchange chromosomal genes. A certain degree of DNA sequence homology is a prerequisite for genetic recombination in vivo. However, recombination between DNA molecules in vitro is not subject to such taxonomic restrictions.

Recombinant DNA is advancement in molecular technology which allows manipulation of genomes of higher organisms and dissection of their complex regulatory circuits. This new methodology is being used to understand the biochemistry of living organisms. The isolation of gene begins with the cloning of fragmented DNA of the organism into appropriate vector. 

Complementary DNA (cDNA) is a double stranded DNA which is an exact copy of the mRNA, i.e. it consists of group of molecules possessing the information contained in various mRNAs but with termini equivalent to or related to those produced by restriction endonucleases. The use of cDNA is an absolute prerequisite for the expression of eukaryotic proteins in bacteria.

The polymerase chain reaction (PCR) is a very powerful new method used for in vitro to amplify a deoxynibonuclic specific region that lies between two regions of known DNA sequence single molecule to million folds in short time. This is achieved by an enzyme taq. DNA polymerase which is thermostable using this enzyme can synthesize microgram quantities of DNA of specified length and sequence from pictogram quantities of complex template in a few hours time.

M13 is a single stranded filamentous DNA phage. Vectors have been developed from M13 phase by Joachim Messing (1983), which are suitable for preparation of single stranded DNA required for sequencing by Sanger’s method. These are derivatives of M13 wild type (size 6.407 kb).

DNA can be sequenced in both double stranded and single stranded templates by cloning in plasmid or phage vectors. There are two sequencing methods.

Protoplasts are cells which have had their cell wall removed, usually by digestion with enzymes. Cellulase enzymes digest the cellulose in plant cell walls while pectinase enzymes break down the pectin holding cells together. Once the cell wall has been removed the resulting protoplast is spherical in shape. Digestion is usually carried out after incubation in an osmoticum (a solution of higher concentration than the cell contents which causes the cells to plasmolyse). This makes the cell walls easier to digest. Debris is filtered and/or centrifuged out of the suspension and the protoplasts are then centrifuged to form a pellet. On resuspension the protoplasts can be cultured on media which induce cell division and differentiation.

Developments in recombinant DNA technology have made it possible to transfer gene from any source across species barrier. In fact, transfer and expression of foreign genes in plant cells is now a routine procedure. Of the several methods tried so far, the system based on Ti plasmid of Aprobacterium tumefaciens appears to be most successful for transformation of plant cells.

The genetic information which makes up the genes of higher plants is stored in DNA sequences of the nuclear chromosomes and the organelle genome. There is such an enormous amount of DNA in higher plant cell, that no two organisms are likely to be identical in DNA base sequence. 

Example: Isolation and Characterization of Protease Inhibitor Gene and Promoter from Black gram (Vigna mungo L.) and Genetic Transformation and Molecular Analysis of Transgenic Tobacco

This research seeks to address some major concerns of communication through cyberspace and its socio-cultural implications. In particular, it seeks to address the use of cyberspace or Internet as a potential medium of communication for the people of Odisha and the relatively positive and negative outcomes of the use of this medium. It investigates the current Internet-mediated communication practice in the twin city (Bhubaneswar and Cuttack) of Odisha and explores the social and cultural implications of the new communication mode.

The aim of the research is to make a study of the role of Internet as a medium of interaction, its impact on the society from the social and cultural point of view. Keeping these objectives in mind, the researcher has referred to contemporary researches, books and articles available in the area. The researcher admits that the number of studies available in the area is very much dispersed. In the line of the research questions formulated for conducting the study, the researcher has explored the relevant studies undertaken so far by different researchers.

This chapter outlines the design of Phase One and Phase Two of the research. It outlines the research approaches and methodology utilized in Phase One and Phase Two of the research. The chapter also provides details of the sampling strategies, data sources, collection and analysis of both the phases; and finally addresses ethical issues.

This chapter reports the analysis of the data collected from Phase One and Phase Two of the research .The chapter is organized in three sections. The first section presents the analysis of the data collected in the first phase through the administration of the survey questionnaire (Appendix-I). It deals with a study of the potential of Internet as a communication tool through an account of the Internet usage habits of the two cities followed by a presentation of their perception, attitudes and internet adoption among the people.

The Internet, new information and communication technologies today are being entrenched into the fabric of our society at a very rapid rate. The Internet has emerged as an extraordinary prominent medium having a tremendous impact on and within society.

The researcher desires to make a study on the socio-cultural aspects of cyber spatial interactions. As you are aware, cyber space or Internet has emerged as a powerful medium of communication. The survey is meant purely for academic purpose and therefore, shall not be passed on to any one and the data obtained from the respondents shall be kept confidential for all practical purposes. The researcher sincerely requests your honest responses. The questions are of people in general, and that there is no right or wrong answers.

Eigen values of the matrix are

(A) 1 and 2             (B) 1 and 3

(C) 1 and 4            (D) 2 and 3

Integrating the function f (x) = 1 + e−x sin (4x) over the interval [0, 1]

using Simpson’s 1/3rd rule gives

(A) 1.021         (B) 0.091

(C) 1.321         (D) 2.642

The curl of the vector A= xyi + yzj + zxk (i, j and k represents unit vectors along the three orthogonal axis) is

(A) xi + yj + zk         (B) – xi – yj – zk

(C) yi + zj + xk          (D) – yi - zj - xk

For station X, the maximum one day rainfall with 25 years return period is 100 mm. The probability of a on day rainfall equal to or greater than 100 mm at station X occurring at least once in 15 successive years is
(A) 0.458             (B) 0.500
(C) 0.637            (D) 0.990

Inverse Laplace Transform of 1/(s - 2)2 is
(A) exp(2t)            (B) t exp(2t)
(C) 2t exp(2t)         (D) t2 exp(2t)

Sun’s radiation corresponding to that of a black body temperature is
about
(A) 50000 K           (B) 60000 K
(C) 70000 K           (D) 140000 K

Direction of rotation can be reversed in
(A) 2- stroke engine           (B) 4- stroke engine
(C) Both (A) and (B)          (D) None of these

A hunting governor is ……….
(A) Less sensitive       (B) More sensitive
(C) More stable           (D) None of these is correct

Q. 1 Which option about the statements made below is correct?
(1) The cooling system maintains engine temperature at 71 to 82ºC for petrol engines.
(2) The thermostat valve begins to open at about 60oC and opens widely at about 71ºC.
(A) Statement (1) is true, but statement (2) is false.
(B) Statement (2) is true, but statement (1) is false.
(C) Both statements (1) and (2) are true.
(D) Both Statements (1) and (2) are false.

Q. 1 In which of the following tractor components, the speed reduction takes place? 
(A) Gear box        (B) Differential
(C) Final drive       (D) All of the above

Q. 1 Improper wheel balancing results in :-
(A) Excessive tyre pressure       (B) Excessive tyre speed
(C) Excessive tyre wear             (D) All above

Q. 1 Toe-in and toe-out are related with
(A) Front axle of tractor     (B) Rear axle of tractor
(C) Tractor steering           (D) Transmission system

Q. 1 A device which is used to store energy in hydraulic system is known as
(A) Motor             (B) Cylinder
(C) Accumulator  (D) Pump

Q. 1 In agricultural tractors, the vibration level is in the range of .......... Hz.
(A) 0 – 2         (B) 2 - 8
(C) 8 – 20       (D) More than 20

Q. 1 If the forward speed of a tractor drawn seed drill is increased twice,
then the seed rate delivered will be
(A) Reduced to half            (B) Double
(C) Increased by four time (D) Remains the same

Q. 1 Operating speed of power sprayer varies from
(A) 2 - 5 km /hr          (B) 4.8 - 8 km /hr
(C) 10 - 20 km /hr      (D) 20 - 35 km /hr

Q. 1 While operating a combine harvester, the grain not collected by the
machine is called
(A) Field loss         (B) Shattering loss
(C) Gathering loss (D) Reel loss

Q. 1 Weight of a manually operated chaff cutter’s fly wheel should not be
below than
(A) 24 kg      (B) 30 kg
(C) 32 kg      (D) 35 kg
(E) 27 kg

Q. 1 Annual depreciation of a machine is included in
(A) Fixed cost         (B) Variable cost
(C) Hiring cost         (D) None of the above

Q. 1 Density of water is:-
(A) 1000 kg/m3    (B) 500 kg/m3
(C) 1500 kg/m3    (D) 2000 kg/m3

Q. 1 Hygrophilic soils are those
(A) Which attract water       (B) Which do not attract water
(C) Which transmit water    (D) Which produce water

Q. 1 The Lysimeter is used to determine
(A) Sun shine hours   (B) Wind velocity
(C) Flow velocity        (D) Evapotranspiration

Q. 1 The development of a tube well should be started from :-
(A) Middle of screen      (B) Top of screen
(C) Bottom of screen     (D) Bottom of casing pipe

Q. 1 A submersible pump may be
(A) Single stage pump       (B) Multi stage pump
(C) Centrifugal pump         (D) Both (A) and (B)

Q. 1 When flow parameters change with time but remain constant with space the flow is called as:-
(A) Unsteady uniform flow       (B) Steady uniform flow
(C) Steady non-uniform flow   (D) Unsteady non-uniform flow

Q. 1 Which of the following is a correct match?
(A) Mole drain = pump drainage
(B) Vertical drainage = well drain age
(C) Pipe drain = well drainage
(D) Horizontal drain = bio-drainage