Question

54. The advantage of a cDNA library of eukaryotic genes compared with a genomic library is that the cDNA library: a. always has the entire gene sequence b. lacks introns C. contains both introns and exons d. consists of single-stranded DNA e consists of RNA and DNA 55. Which of the following is an example of a cloning vector? a. Human growth hormone b. Mosquito c. Plasmid d. Tick e. Ribosomal RNA 56. Transformation in recombinant DNA technology: a. Requires a recipient cell to be "competent." b. Requires a conjugative plasmid. c. Requires a virus to inject the donor DNA d. Results in the transfer of a complete set of genetic information from donor to recipient 57. Which of the following is true about transduction? a. Recombination does not occur. b. Naked DNA is passed from bacterium to bacterium. c. Bacteria-bacteria contact is required. d. A virus is required for transfer of genetic material. e. Segments of DNA move from one region of DNA to another. 58. E. coli makes insulin because a. It needs to regulate its cell-glucose level. b. It's an ancient gene that now has no function. c. The insulin gene was inserted into it. d. It picked up the insulin gene from another cell. e. No reason, it doesn't make insulin. 59. A reaction to make multiple copies of a piece of DNA enzymatically is called Polymerase Chain Reaction (PCR) True/ False

Answer 1

54)

The correct answer is option B, lacks introns.

A cDNA is obtained by the reverse transcription of mRNA using reverse transciptase enzyme and hence lacks introns.

A genomic DNA is the natural genetic DNA which has bot introns and exons in case of eukaryotes.

55)

The correct answer is option C, plasmid.

Plasmid is a small circular extrachromosomal DNA found in bacteria which are present in the cytoplasm and they can replicate independently. So they can multiply the gene inserted into them without the bacterial cell replicating its own DNA. That is why they are called cloning vectors.

The other options:

Human Growth Hormone is responsible for the growth of bones, cell division etc in human beings.

Mosquito is an insect that is a vector for malaria and other diseases.

Ticks are parasites and they live by feeding on the blood of its host.

Ribosomal RNA or rRNA is responsible for protein synthesis.

56)

The correct answer is option A, requires a recipient cell to be "competent".

Transformation is the process by which some bacterial cells take up foreign DNA or naked DNA for cloning. The bacterial cell that takes up the foreign gene is called a competent cell.

Virus is not required for the process and the complete set of genetic material is also not transferred only genes of interest are transferred.

57)

The correct answer is option D, A virus is required for the transfer of genetic material.

The very definition of transduction is that genetic material or foreign DNA is transferred to a bacterial using a virus as a vector.

Bacteria contact is not required, can occur even without contact.

Recombination occurs as foreign DNA is introduced into a bacteria.

Segments of DNA are cut using restriction endonuclease enzymes and transferred to bacterial cells for cloning.

58)

The correct answer is option C, the insulin gene was inserted into it.

By recombinant DNA technology we can create genes of interest by introducing them into cloning vectors. Artificial insulin is created for the treatment of patients by introducing the gene into E.coli and allowing them to create multiple copies of it in their plasmids.

59)

The answer is TRUE.

In polymeric chain reaction multiple copies of the gene of interest is created in vitro using two sets of primers and the enzyme DNA polymerase.