RNA interference takes place in all eukaryotic organisms as a method of :

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Restriction endonuclease on finding its specific recognition sequence, bind to the DNA and cut each of the two strands of the double helix at specific points in their sugar -phosphate backbones. Each restriction endonuclease recognises a specific palindromic nucleotide sequences in the DNA. Since the DNA is enclosed within the membranes, we have to break the cell open to release DNA along with other macromolecules such as RNA, proteins, polysaccharides and also lipids. This can be achieved by treating the bacterial cells/plant or animal tissue with enzymes such as lysozyme (bacteria), cellulase (plant cells), chitinase (fungus). Now a days the most commonly used matrix is agarose which is a natural polymer extracted from sea weeds. The DNA fragments separate (resolve) according to their size through sieving effect provided by the agarose gel. The first restriction endonuclease-Hind II, whose functioning depended on a specific DNA nucleotide sequence was isolated and characterised five years later. It was found that Hind II always cut DNA molecules at a particular point by recognising a specific sequence of six base pairs. In addition to 'ori', the vector requires a selectable marker, which helps in identifying and eliminating non-transformants and selectively permitting the growth of the transformants. Transformation is a procedure through which a piece of DNA is introduced in a host bacterium. Normally, the genes encoding resistance to antibiotics such as ampicillin, chloramphenicol, tetracycline or kanamycin, etc., are considered useful selectable markers for E. coli.
A natural polymer extracted from sea weeds used in the field of biotechnology is:

The amount of biomass or organic matter produced per unit area over a time period by plant during photosynthesis is defined as:

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Recombinant DNA Technology Asexual reproduction preserves the genetic information, while sexual reproduction permits variation. Traditional hybridization procedures used in plants and animals breeding very often lead to inclusion and multiplication of undesirable genes along with the desired genes. The techniques of genetic engineering, which include creation of recombinant DNA, use of gene cloning and gene transfer, overcome this limitation and allow us to isolate and introduce only one or a set of desirable genes without introducing genes into the target organism.
In Recombinant DNA Technology, what is the role of the "selectable marker gene"?

Spermiogenesis is the process of formation of:

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Secondary treatment or biological treatment: The primary effluent is passed into large tanks where air is pumped into it. This allows vigorous growth of aerobic microbes. While growing, these microbes consume the major part of the organic matter in the effluent. This significantly change the BOD (biochemical oxygen demand) of the effluent. The effluent in then passed into a tank a small part of the sludge is pumped back into the aeration tank to serve as the inoculum. The remaining major part of the sludge is pumped into large tanks called sludge digesters. Here, other kinds of bacteria grow anaerobically in the sludge. The biogas produced can be used source of energy as it is inflammable. The effluent from the secondary treatment plant is generally released into natural water bodies like rivers and streams.
Steps in primary treatment does not include:

RNA polymerase III is responsible for transcription of -

Two long and parallel straight wires, each carrying current \(I\) in the same direction, are separated by a distance of 40 cm. If the force of attraction per metre between them is \(2 \times 10^{-6} \text{ N/m}\), the value of \(I\) will be: (Given: \(\mu_0 = 4\pi \times 10^{-7} \text{ T}⋅­­m⋅­­A^{-1}\))

Match List-I with List-II

List-I (Techniques)	List-II (Related features)
(A) ELISA	(I) Production of mature insulin
(B) PCR	(II) Antigen-antibody interaction
(C) Autoradiograph	(III) Amplification of DNA
(D) Recombinant DNA technology	(IV) Photographic film

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A battery of emf 3 V and internal resistance \( r \) is connected in series with a resistance of \( R = 55 \text{ } \Omega \) through an ammeter of resistance \( R_A = 1 \text{ } \Omega \). The ammeter reads a current \( I = 50 \text{ mA} \). Find the internal resistance \( r \) of the battery.

Choose the correct statements:
(A) The angle of incidence corresponding to an angle of refraction \(90^{\circ}\) is called critical angle (i).
(B) Refractive index of denser medium \(\mu=\frac{1}{\sin \left(i_c\right)}\).
(C) For \(i>i_c\), Snell's law of refraction cannot be satisfied.
(D) The refractive index of air increases with decrease in density.
(E) Rainbow is the combined effect of dispersion, refraction and reflection of sunlight by droplets.
Choose the correct answer from the options given below :

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Salmonella typhi is a pathogenic bacterium which causes typhoid fever in human beings. Sustained high fever (39° to 40°C), weakness, stomach pain, constipation, headache and loss of appetite are some of the common symptoms of this disease. Typhoid fever could be confirmed by Widal test. Plasmodium enters the human body as sporozoites. The parasites initially multiply within the liver cells and then attack the red blood cells (RBCs) resulting in their rupture. The rupture of RBCs is associated with release of a toxic substance, haemozoin, which is responsible for the chill and high fever recurring every three to four days. There is lymphoid tissue also located within the lining of the major tracts (respiratory, digestive and urogenital tracts) called mucosa-associated lymphoid tissue (MALT). In our body, cell growth and differentiation is highly controlled and regulated. In cancer cells, there is breakdown of regulatory mechanisms. Normal cells show a property called contact inhibition by virtue of which contact with other cells inhibits their uncontrolled growth. Cancerous cells just continue to divide giving rise to masses of cells called tumors. Tumors are of two types: benign and malignant. Cannabinoids are a group of chemicals, which interact with cannabinoid receptors present principally in the brain. Generally taken by inhalation and oral ingestion, these are known for their effects on cardiovascular system of the body.
Which one of the following statements is not true?

Identify the enzyme that is used to clarify fruit juices before bottling.