BIOLOGY 1 Marks Question

Meiosis I- Pachytene- When recombination nodule appear after synaptonemal complex formation.

Alien DNA must be linked to ori/origin of replication/site to start replication.

Bacteria: Lysozyme, fungi: chitinase.

Exonuclease: removes nucleotides from the ends of DNA molecules.
Endonuclease: makes cut at specific position within a DNA.

Gen for chain A and gene for chain B of insulin are prepared, inserted, into plasmid, of E.coli separately, E.coli cultured and chain extracted, combined by disulphide bonds (to produce human insulin).

(Gel) electrophoresis.

Plant cells.

Plant cells have cell wall made up of cellulose where as animal cell lack cell wall and do not contain cellulose. Therefore the enzyme cellulose is needed for isolating genetic material for plant cell only.

(Breaking the cell open) Treating with lysozyme.

The recombinant plasmid will lose tetracycline resistance due to inactivation of tet^R gene but can still be selected out from non-recombinants by plating the transformants on ampicillin containing medium.

The instrument for bombarding micro-projectile particles (gold/ tungsten particles) coated with foreign DNA, with great velocity, into a target cell is called gene gun.

Rerstriction enzymes.

Thermus aquaticus.

Hepatitis B recombinant vaccine-engerix is used for vaccination of hepatitis virus.

They act as molecular scissors to cut DNA at specific locations.

Normal Endonuclease makes cuts at random positions within a DNA sequence. Restriction endonuclease makes cuts only at specific positions within a DNA sequence.

They are carriers or vehicles of desired DNA fragments which can replicate independently to increase copies of desired genes in the host cell, e.g., plasmids, bacteriophages.

DNA ligase.

The DNA molecule that carry a foreign gene segment and replicate inside host cell is called vector.

Ethidium bromide.

E. coli and Saccharomyces cerevisiae.

Agarose.

Retroviruses in which its disease causing gene is removed (inactivated) can be used as vectors to deliver the recombinant alien DNA into animal cells.

In the absence of a selectable marker, it will not be possible to identify the recombinants from the non recombinants.

Origin of replication (ori).

Restriction endonucleases.

Competent host organism. The product is called recombinant molecule.

Retroviruses are disarmed (diseases-causing gene is removed/ inactivated) and used as vectors to deliver the recombinant/ alien DNA into animal cells.

Gel electrophoresis.

In case ofligation at sal I site, the transformant loses the tetracycline resistance while, in case of pvu I, the transformant loses ampicillin resistance.

rDNA- Recombinant DNA.
BACs- Bacterial Artificial Chromosomes.
YACs- Yeast Artificial Chromosomes.

Genetic engineering.

Endonuclease.

European Federation of Biotechnology.

Due to the presence of cell wall in plants, cellulase is used, whereas the animal cell lacks cell wall.

Creation of recombinant DNA, gene cloning and gene transfer.

Plasmids and bacteriophages.

PCR refers to Polymerase Chain Reaction. This technique was developed by Kary Mullis in 1985.

Lysozyme digests bacterial wall and chitinase digests fungal cell wall.

For bacteria- lysozyme.
For fungus- chitinase.

Tumour inducing plasmid of Agrobacterium tumefaciens is called Ti plasmid.

Salmonella typhimurium.

Palindromes are group of letters (sequences) that read same both in forward and backward direction.

R stands for RY 13, the strain of E.coli bacterium.

DNA is a hydrophilic molecule; hence it cannot enter through plasma membrane.