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.

Gelelectrophoresis.
Or
Gel electrophoresis is used to separate fragments of DNA cut by restriction endonucleases.

The main function of sampling port is to withdraw culture periodically.

Since plasmids can replicate within the bacterial cell independently of the genomic DNA, any alien DNA ligated to it well also multiply, i.e. It is used as a vector as well as in gene cloning.

Restriction refers to the restriction or retardation of multiplication of bacteriophages in a bacterial cell.

The branch of biotechnology which is done by altering the original DNA sequence of an organisms by using recombinant DNA technology.

• One of them (exonucleases) added methyl groups to DNA.
• The other (endonucleases) cut the DNA at specific points within the DNA.

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.

Animal cells.

It is the source of thermostable DNA-polymerase enzyme.

E. coli and Saccharomyces cerevisiae.

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.

Origin of replication (Ori).

DNA polymerase from Thermus aquaticus remains active during the high temperature induced denaturation of double stranded DNA.

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

By using Alkaline phosphatase enzymes.

K. Mullis.

A bioreactor is a large vessel in which raw materials are biologically converted into specific products individual enzymes, etc., using microbial, plant, animal or human cell.

Penicillin will kill the antibiotic sensitive E. coli cells.

It is generally a 100-1000 litre cylindrical metal container with a curved base to facilitate mixing of contents. In bioreactors, raw materials are biologically converted into products.

Antibiotic resistance gene and plasmid.

Taq, DNA.

DNA is a hydrophillic molecule which can not pass through the cell membrane, so to make it competent to take up DNA, bacterial cells should be treated with divalent cations or calcium so that DNA can enter through the pores of cell wall.

1. Sea weeds.
2. Agrobacterium tumefaciens.

By spooling method.

Creation of recombinant DNA, gene cloning and gene transfer.

This is because crossing over occurs in this phase which helps to produce recombinants.

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.

Blunt or flush ends.

Ampicillin-resistance gene and tetracyclin-resistance gene.

Because thermostable DNA polymerase remains active even at high temperature required for extension step of PCR.

Genetic engineering.

• Proteins are removed by using proteases.
• RNAs are removed by using ribonucleases (RNases).

Restriction endonuclease and DNA ligase.

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.

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

It is because the normal E.coli cells do not have resistance to any such antibiotics.

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