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

The DNA fragments are negatively charged so they move towards the positively charged anode.

Because they can be used in vitro to recognize and cut within specific DNA sequence typically consisting of 4-8 nucleotides.

Penicillin will kill the antibiotic sensitive E. coli cells.

Hind II (From Haemophilus influenzae bacterium)

Restriction enzymes recognise the specific sequence in DNA and cut within that recognition sequence.These enzyme help in cutting the genes and plasmids and produce sticky or blunk end.

Recombinant DNA is the DNA formed by combining DNAs from two different organisms.

Antibiotic resistance gene and plasmid.

Protease is added because it helps in digesting proteins and helps in the breakdown of cell wall by dissolving it.

Ethidium bromide.

 By spooling method.

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.

European Federation of Biotechnology.

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

Agarose; it provides the sieving effect for the DNA to resolve according to their size.

Rerstriction enzymes.

Thermus aquaticus.

Genetic engineering.

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.

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

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

Ethidium bromide (EtBr) exchanges its visible range of wavelength with the invisible wavelength of DNA to make it visible under UV light.

The transformant loses ampicillin-resistance.

pBR322.

The transformant loses the tetracycline-resistance.

The gel is stained by ethidium bromide, to view the separated DNA bands when exposed to UV light.

Electrophoresis was developed by Tiselius in 1937 and is based on the principle that charged particles move under the influence of electric current to oppositely charged electrodes.