(a) (i) Explain any two basic principles/core techniques on which biotechnology is based. (ii) Describe any three key tools used in Recombinant DNA…

• Genetic Engineering

Technique to alter the chemistry of genetic material (DNA and RNA) to introduce these into host organisms and thus change the phenotype of the host organism.

• Bioprocess Engineering

Maintenance of sterile ambience in chemical engineering process to enable growth of only the desired microbe/eukaryotic cell in large quantities for the manufacture of biotechnological/ biological products like antibiotics, vaccines, enzymes etc.

• Restriction Enzymes

(Molecular Scissors)

Cut DNA at specific point on sugar phosphate backbone /They cut DNA at specific recognition sequences, called palindromes

They create sticky ends

• Cloning vectors

These are DNA molecules used to carry foreign genes into a host cell.

• Competent host

These are living organisms in which recombinant DNA is introduced

Urine analysis/ stool analysis/ sputum analysis/ Serum Analysis

Disadvantages: Early detection not possible/ Detect the disease when it has spread/ shows symptoms

Three molecular diagnostic techniques:

• Polymerase chain Reaction (PCR)

Amplifies specific DNA sequences from very small samples.

• ELISA (Enzyme Linked Immuno Sorbent Assay)

Based on antigen - antibody interaction infection by pathogen can be detected by the presence of antigen / by detecting the antibodies synthesised against the pathogen.

• A single stranded DNA or RNA tagged with radioactive molecule

(probe) is created it binds to its complementary DNA in a clone of cells followed by detection using autoradiography,

Clone having mutated gene will not appears on photographic film as it does not have complementarity.