ANSWER THE FOLLOWING QUESTIONS(COULD BE MORE THAN ONEANSWER)
19) Describe the roles of M13 genes and their proteins:
a) Genes 1, 4 and 11 produces proteins required for assemblingthe the phage.
b)Genes 3.6,7,8 and 9 produces capsid proteins.
c)Gene 2 nicks the circular phage ssDNA to make it doublestranded by DNA polymerase
d)Gene 5 produces single strand binding proteins and gene 10protein makes M13 SSDNA circular.
e)Protein five bound single stranded circular M13 moved to theE. coli membranne and is released out coated will proteins 3, 6, 7,8 and 9 .
2) What is a phagemid and how does it work?
a)it is a recombinant DNA with a filamentous phage genome and aplasmid genome.
b)it carries two origins of replication: eg., oir f1 and oriColE1
c)May carry a gene for selection: e.g. Ampr gene.
d)May carry a marker gene; e.g, lacZ gene with promoter andregulator
e)May contain MCS, as is pUC18.
3)For storing functional gene for future applications you willneed the following:
a)A vector DNA
b) A cloning site in the vector matching with the ends of a geneto be cloned
c)A host organism capable to hold the recombined vector.
d)A marker gene present in the recombinant vector
e)A functional gene of interest.
24)identify which of the following is true for thebacteriophage lambda?
a)It has two major body parts, the head and the tail.
b)The genome is approximately 49 thousand bases long.
c) It has a linear dsDNA with single stranded 12 bases long costerminals at both
d) The single stranded lambda DNA cos terminals appear to be asfollows: (a) GGGCGGCGACCT and (b)CCCGCCGCTGGA
e)it can accept 7-10 kb long foreign DNA replacing itsnon-essential b2 region.
29) For developing a recombinant lambda DNA with a gene ofinterest and expressing the gene in a host you have to take thefollowing steps:
a)Remove the b2 region from lambda DNA using a restrictionenzyme
b)digest the gene of interest, outside its stop and startcodons, with the same restriction enzyme.
c)Recombine the lambda DNA digest with the digested gene ofinterest carrying complementary overhangs with ligase.
d)Form lambda particles by adding head proteins, tail proteinsand packaging enzynes to the recombined lambda DNA.
e)Add the packaged lambda particles to Agrobacetrium tumefaciensand incubate them in culture.
f)Add the packaged lambda particles to laboratory strains ofEscherichia coli and incubate them in culture.
32)The amino acids coded by our genes differ by thefollowing:
a)Polarity
b) Acidity
c)Basicity
d)Aroma
e)Hydrophobicity
38)What is an M13 phage and what are its specialty?
a)They are rod shaped Escherichia coli bacteriophage.
b)ts genome is made of a single stranded circular DNA.
c)Its DNA is 6400 nucloetides long coding for elevenproteins.
d)After infecting a bacterial cell it starts replicating in 10minutes producing 1,000 phages in an hour
e) soon its kills the host Escherichia coli and gets out to theenvironment.
40)You have a gene with BamH cut sites out side its start andthe stop codons. You can use the following procedures to prepare aclone of the gene in pBR322 and select the transformed E.Coli cellscarrying pBR322, except:
a) Digest both the gene and the plasmid pR322 with BamH1
b) Ligate the fragments using T4 DNA ligase.
c)Transform E coli with the reconstructed plasmid
d)Select the cells transformed cells grow in Lb-agar-ampicilinplates
e)Select the cells transformed cells grow inLB-agar-tetracycline plates
