Tala Bilal-12G
18/11/2015
Engineering a Transgenic Organism
Tala Bilal-12G
18/11/2015
Tala Bilal-12G
18/11/2015
Journal Questions:
1) DNA is made up of two separate strands of base sequences. The same sequence is
found on both strands, but running in opposite directions. What word describes
this characteristic?
The word could be palindrome, which means: sentences that read the same in the
forward and backward; the DNA has a double-helix structure.
2) What does the term ‘sticky ends’ refer to in gene splicing?
Some restrictive enzymes cut DNA sequences so that double-stranded fragments
with single-stranded ends are formed. The dangling single stranded ends have a
tendency to join with other single-stranded ends to become double-stranded, so
they tend to attract DNA that they can join with. For this reason, these ends are
called sticky ends.
3) What is a plasmid? How is a plasmid used in gene splicing?
A plasmid is a small ring of DNA found in a bacterial cell. A plasmid is often used as a
vehicle, or vector, to deliver DNA to a host organism.
4) What types of vectors are used to carry DNA from one species into the DNA of
another species? Give examples.
Tala Bilal-12G
18/11/2015
Biological and mechanical vectors are used in gene splicing. Examples of biological
vectors include bacterial plasmids and viruses. Micropipettes and gene guns are
examples of mechanical vectors.
5) What is a ‘transgenic organism’? Give examples.
A transgenic organism is an organism that contains functional foreign DNA.
Examples include a tobacco plant that glows in the dark (created by splicing the DNA
that causes a firefly to glow into the DNA of a tobacco plant). Or a bacterium that
produces human insulin (engineered by splicing the DNA that causes human insulin
production into the DNA of an E. coli bacterium).
6) Why is it essential that the same restriction enzyme be used to cleave (cut) the
DNA of both organisms used to create a transgenic organism?
To be spliced together, both pieces of DNA must have matching sticky ends, so that
the pieces will be capable of joining together at these ends. The only way to ensure
that both pieces of DNA have matching ends is to cut both of them with the same
restriction enzyme.
7) Are there any factors other than technical ones that might slow ñ or even prevent ñ
the use of bioengineering?
Ethical questions, such as concerns regarding unintentional cruelty to transgenic
animals, unanticipated health dangers that may be present in transgenic foods and fears
that gene-splicing will be used to create transgenic human beings are all factors that
may slow or prevent the widespread use of bioengineering.