GATE computer Science

Living organisms which can harm plants, such as viruses, fungi and bacteria and harmful insects are known as biotic stresses.
The organisms which grown on dead organisms are called saprophytes like  bacteria, fungi, etc.

Genetic material of organism is deoxyribonucleic acid or DNA.
In order to cut the DNA with restriction enzymes, it needs to be in pure form, free from other macromolecules. 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 tissues with enzymes such as lysozyme, cellulase and chitinase.
Hence, lysozyme and cellulase enzymes are used in the isolation of the genetic material.

Transgenic crops like - corn, tomato, soybean, cotton, potato, grapeseed, squash, beets, papaya, rice, flax, maize and chicory have been approved for commercial production in the USA. The most widely grown are “Bt” corn and cotton and glyphosate-resistant soybeans. Bt corn and cotton have had DNA from a naturally occurring insecticidal organism, Bacillus thurin-giensis, incorporated into their genome; it kills some of the most serious insect pests of these crops after they feed on the plant, while beneficial insects are left unaffected.

In the year 1963, the two enzymes, restriction exonuclease and restriction endonuclease, responsible for restricting the growth of bacteriophage in Escherichia coli were isolated.
One of these enzyme (exonuclease) added methyl groups to DNA, while the other cut DNA (endonuclease). Restriction exonuclease removes nucleotides from the ends of the DNA, whereas restriction endonuclease makes cuttings at specific positions within the DNA.

The restriction enzyme and the recognition sequence for bacteria-Streptomyces albus are Sa-II and 5’ GTCGAC; 3’ CAGCTG respectively. 

Harmful chemicals in the form of toxins are called bio-weapons, produced by various species of Fusarium, Myrotecium, Trichoderma, Cephalosporium, etc.
The chemicals cause very dangerous diseases to human beings such as bloody diarrhea, weight loss, nervous disorders, cardiovascular alterations, immune-depression, hemostatic derangements, skin toxicity, decreased reproductive capacity and bone marrow damage.
Hence, Fusarium is used as a bio-weapon in warfare.

The target of aspirin action. Its hydrophobic helices do not span the whole membrane but interact strongly with the acyl groups on one side of the bilayer.

The overall hydrophobicity of a sequence of amino acids is estimated by summing the free energies of transfer for the residues in the sequence, which yields a hydropathy index for that region.

Prion-related protein or PrP is a normal protein, expressed in the nervous system of animals, whose structure when altered (by interaction with altered copies of itself) is the cause of scrapie in sheep, BSE in cattle and Creutzfeldt-Jakob disease in humans.

The restriction enzyme for Escherichia coli is EcoR-II with recognition sequence of 5’ CCWGC; 3’ GCWCC.
The restriction enzyme for Escherichia coli is EcoR-V with recognition sequence of 5’ GATATC; 3’ CTATAG.

Monoclonal antibody OKT3 has antigen of type T3, which represents reactivity with epidermal Langerhan’s cells.

(continuous fragments ) are clones containing neighbouring DNA fragment having an overlapping regions. Contigs greatly facilitate mapping and ultimately the correct alignment of base sequence data.

About 1% of human chromosomal DNA is stably unmethylated, these regions are called CpG islands, since they contain more than 50% of C+G. These sequences are used as powerful markers for genome mapping.

The cutting of DNA by restriction endonuclease results in the fragments of DNA. These fragments can be separated by a technique known as gel electrophoresis. DNA fragments are negatively charged molecules and can be separated by forcing them to move towards the anode under an electric field through a medium.

Yes, this results in the formation of micelles.

A gene whose expression allows one to identify cells that have been transformed or transfected with a vector containing the marker gene is known as a selectable marker which helps in identifying and eliminating non-transformants and selectively permitting the growth of the transformants.
Normally, the genes encoding resistance to antibiotics such as ampicillin, chloramphenicol, tetracycline or kanamycin, etc. are considered as useful selectable markers for Escherichia coli.
Hence, the set ‘ampicillin, chloramphenicol, tetracycline’ represents selectable marker for Escherichia coli.