Question 1

For genes that are highly conserved, probes developed from one species can be used to screen clones from many other species.

Accepted Answer

Highly conserved genes have similar sequences across different species, allowing probes from one species to hybridize with DNA from other species.

Question 2

It is possible for eukaryotic genes with introns to be isolated from genomic libraries and expressed directly in yeast cells.

Accepted Answer

Eukaryotic genes with introns can be expressed directly in yeast cells because yeast cells have the machinery to remove introns from RNA transcripts.

Question 3

Complementary DNA cDNA is single-stranded DNA made with reverse transcriptase.

Accepted Answer

Complementary DNA (cDNA) is actually double-stranded DNA synthesized from a single-stranded RNA template using the enzyme reverse transcriptase.

Question 4

Cloned cDNA is used less frequently than mRNA as a probe for protein encoding genes in genomic DNA libraries.

Accepted Answer

Cloned cDNA is used more frequently than mRNA as a probe because it is more stable and easier to work with in laboratory settings.

Question 5

Changing factors such as the salt concentration and temperature can be used to vary the stringency of hybridization and allow for more or less mismatches in base pairing.

Accepted Answer

Adjusting salt concentration and temperature affects the stability of DNA duplexes, influencing the stringency of hybridization by allowing more or fewer mismatches in base pairing.

Question 6

RFLP analysis is a very useful technique for genetic analysis and forensic studies, but it is not precise enough to distinguish genetic differences between highly related individuals such as siblings or parents and children.

Accepted Answer

RFLP analysis can distinguish genetic differences between highly related individuals because it detects variations in DNA sequences, which can be unique even among close relatives.

Question 7

The oligodeoxythymidylate oligo dT fragment functions as a primer for synthesis of a complementary DNA strand by reverse transcriptase.

Accepted Answer

Oligo dT binds to the poly-A tail of mRNA, providing a starting point for reverse transcriptase to synthesize complementary DNA.

Question 8

RFLPs are very useful in determining paternity.

Accepted Answer

RFLPs (Restriction Fragment Length Polymorphisms) analyze variations in DNA sequences, which can be used to compare genetic similarities between individuals, making them useful for paternity testing.

Question 9

Exons and introns are equally represented in a cDNA library.

Accepted Answer

A cDNA library is made from mRNA, which only includes exons, as introns are removed during RNA splicing.

Question 10

Chromosome walking involves the isolation and sequencing of consecutive segments of DNA isolated after treatment with a restriction endonuclease.

Accepted Answer

The answer of Chromosome walking involves the isolation and sequencing...

Question 11

In general, when constructing a YAC library of genomic DNA the smaller the insert used the fewer clones are needed.

Accepted Answer

A smaller insert size means more clones are needed to cover the entire genome, as each clone contains less genomic information.

Question 12

An individual is treated for cystic fibrosis by a recombinant virus administered through an inhaler so the virus can ʺinfectʺ the cells lining the lungs. In the lungs, the recombinant DNA is incorporated into the patientʹs genomic DNA and produces a protein product that helps relieve the symptoms of the disease. Children born to this patient after the treatment can be expected to also carry the recombinant genes and benefit from them if they too suffer from cystic fibrosis.

Accepted Answer

The recombinant DNA introduced by the virus affects only somatic cells in the lungs, not germ cells, so it is not passed on to offspring.

Question 13

Insulin and growth hormones are two examples of proteins that can be produced in great quantities by their synthesis in bacteria.

Accepted Answer

Bacteria can be genetically engineered to produce proteins like insulin and growth hormones, allowing for large-scale production.

Quiz 23: Recombinant Dna Technology