12. POST-TEST

This post-test should be done after you have studied the on-line learning material. You should already have tried the pre-test provided in Section 1 before you started the on-line material. 

The questions that follow are organized into sections corresponding to the numbering of the on-line material. You are advised to answer the questions briefly on a piece of paper before accessing the answers by clicking on the links. This way you can judge your progress and identify any possible problems for discussion with the lecturer. After accessing the answers, return to this page using the Back button on your browser.

Where appropriate, you should also look at the past examination papers and mark schemes provided for your module and attempt the questions in the set times given.

Section 2: Background

1.    Define the term: 'gene manipulation' (GM).     Answer

2.    Give 5 main areas of science and industry that can benefit from the
        applications of GM.      Answer

3.    Name 3 natural processes found in bacteria that produce recombination.     Answer

4.    Who first discovered the restriction of bacteriophage DNA in bacterial
        host cell strains, and when?     Answer

5.    How many types of restriction endonuclease enzyme are there?     Answer

Section 3: Manipulation of DNA

1.    Name at least 5 different categories of enzyme used in GM work and briefly
        describe the mode of action of each.     Answer

2.    Restriction enzyme recognition sequences are usually written for one
        DNA strand only and running in one particular direction.
        What is this direction?     Answer

3.    What is the recognition sequence, cleavage point and methylation pattern
        for the restriction enzyme, EcoRI?     Answer

4.    What is an 'isoschizomer'?     Answer

5.    Briefly describe the use of synthetic linkers to join DNA fragments.     Answer

Section 4: Analysis of DNA

1.    What sort of gel would you use to separate DNA fragments with the following size ranges:
a)    1000 - 9000 base pairs
b)    30 - 60 base pairs
c)    2 - 8 kilobase pairs      Answer

2.    Give an equation relating the migration rate (mobility) of nucleic acid fragments
        during electrophoresis to their size.     Answer

3.    The relative speeds of DNA samples run in the same gel depend on 2 main factors.
        What are they?     Answer

4.    Briefly describe the main stages in the production of a Southern blot.     Answer 

5.    What is an 'RFLP'?     Answer

Section 5: Host-vector systems

1.    List at least 5 characteristics required of a good prokaryotic GM vector.     Answer

2.    Draw maps of the important features of the genomes of at least 2 examples of vectors.
        Example 1  Example 2  Example 3  Example 4  Example 5

3.    Looking at Example 1 provided in the above question as an example of a vector,
        predict the phenotype of a host cell carrying it if the vector molecule had
        previously been cut with PstI restriction enzyme followed by insertion
        and ligation of foreign DNA.     Answer

4.    What is 'in vitro packaging' and what vectors might show this feature?
        Answer 1  Answer 2

5.    What vector might be especially useful for the production
        of probes and primers, and why?     Answer 

Section 6: Complementary DNA

1.    What is cDNA?    Answer

2.    What might be the two advantages of using cDNA instead of genomic DNA
        in recombinant DNA work?    Answer 1    Answer 2

3.    Name the enzyme used to synthesize cDNA, and its source.    Answer

4.    Describe the stages in the synthesis of cDNA.    Answer

5.     List the uses of cDNA.    Answer

Section 7: Gene probes

1.    What is a gene probe?    Answer

2.    a)    Name the most sensitive type of label for a gene probe and outline
                its major disadvantage.    Answer

        b)    List 5 different methods of labelling probes and describe the most
                commonly used method in detail.    Answer

3.    Define 'stringency' and name the 4 conditions that can affect it.     Answer

4.    Draw a graph of temperature against the percentage hybridization
        of two complementary DNA samples. Answer

5.    What are the uses of gene probes?     Answer

Section 8: DNA amplification

1.    Name two methods for the amplification of DNA apart from PCR.
        Answer 1    Answer 1

2.    List the requirements for the polymerase chain reaction.     Answer

3.    How many stages are involved in a PCR cycle, and what are they?
        Answer

4.    What are the advantages and disadvantages of using Taq polymerase
        in the polymerase chain reaction compared to other enzymes such as
        E.coli polymerase I or T4 polymerase?     Answer

5.     Give at least 5 applications of PCR.
        Answer 1    Answer 2    Answer 3    Answer 4    Answer 5
        Answer 6    Answer 7

Section 9: Protein engineering and SDM

1.    What is 'mutagenesis'?    Answer

2.    How can mutagenesis be carried out?    Answer

3.    Explain the term 'protein engineering'.    Answer

4.    What is SDM?    Answer

5.     Describe a named method for carrying out SDM.    Answer

Section 10: DNA sequencing

1.    Which DNA sequencing method uses double-stranded DNA and
        chemical cleavage?    Answer

2.    Which DNA sequencing method uses single-stranded DNA and
        chain termination?    Answer

3.    Describe the stages in a the DNA sequencing method named in Q2.
        Answer

4.    Which of the two DNA sequencing methods is now the more common,
        and why?    Answer

5.    What is the Human Genome Project?    Answer

Section 11: Gene libraries

1.    Define the term 'gene library'    Answer

2.    What is a 'cDNA library' and is it smaller or larger than a gene library?
        Answer

3.    List the stages in the construction of a library.    Answer

4.    Assuming the human genome is 2.8 x 10⁶ kilobases (kb) in size and that
        a lambda vector (maximum insert size = 20kb) is used to make a gene library,
        how many actual clones would be required to achieve a 95% probability of
        including a particular gene sequence?    Answer

5.    Screening a gene library can be carried out using two different approaches,
        what are they?    Answer

Transgenesis

This section is not covered nor assessed in the Recombinant DNA Technology module.

Remember to also look at the past examination papers provided for your module and attempt the questions in the set times given. Also, look at the mark schemes given for some of the past papers. These are provided for the benefit of External Examiners but students should also find them useful as they indicate what points they need to make to answer the questions successfully and score good marks.

THIS IS THE END!
RETURN TO GM & rDNA HOME PAGE.