1. Genetic Engineering
Study Guide Review

2. What 3 techniques do scientists use to sequence DNA from a cell?
cut, separate, and read

3. Why do scientists cut DNA into smaller pieces. What do they use
Why do scientists cut DNA into smaller pieces? What do they use? Where do they get it? What do they call the small pieces of DNA? DNA molecules from most organisms are much too large to be analyzed, restriction enzymes, bacteria , restriction fragments

4. What is a “sticky end”? What does it “stick” together? single-
stranded overhangs of DNA, can “stick,” to a DNA fragment with the complementary base sequence

5. What is gel electrophoresis used for? to separate and analyze the
differently sized fragments of DNA

6. What happens when an electric voltage is applied a gel containing
DNA samples? DNA molecules—which are negatively
charged—move toward the positive end of the gel

7. What does a gel look like after electrophoresis?
a pattern of bands based on fragment size

8. After DNA has been separated into pieces, what has to happen to
these fragments? researchers read, or sequence DNA

9. When single stranded DNA fragments are added to a mixture of the
four bases (A, C, T, and G), what enzyme is used to copy the single stranded
DNA fragments, one new DNA strand after another? DNA polymerase

10. When bases that have a chemical dye attached are added to a new
DNA strand, what happens? the synthesis of that strand stops

11. The resulting color-coded DNA fragments of different lengths can be separated further by gel electrophoresis. Why is the order of colored bands on the gel important? The order tells the exact sequence of bases in the DNA

12. What is selective breeding? What is it used for? A technique
used to produce animals with certain desired traits by taking
advantage of naturally occurring genetic variation, to pass wanted
traits on to the next generation of organisms

13. Why can breeding by hybridization often be better than inbreeding?
individuals produced by such crosses are often hardier than either of
the parents

14. Why is inbreeding risky? It increases the chance that a cross between
two individuals will bring together two recessive alleles for a
genetic defect

15. What is genetic engineering? Name 3 things that can be done to
DNA through genetic engineering. the use of technology to
manipulate and change genes; insert, remove, or alter an
organism’s DNA

16. How can breeders increase the mutation rate of an organism?
Cite an example where this would be beneficial. by using
radiation or chemicals, strains of oil-digesting bacteria

17. What is a polyploid plant? Why is this advantageous over diploid plants?
Is polyploidy useful in animals? Plants that have many sets of
chromosomes, they are hardier, no-fatal in animals

18. What is recombinant DNA technology? How is it accomplished?
joining together DNA from two or more sources; DNA is cut and
recombined in different ways

19. What is a transgenic organism? What is another name for
this organism? An organism containing genes from
other species; GMO

20. How are transgenic organisms created? the insertion of
recombinant DNA into the genome of a host organism

21. What is gene therapy? changing the DNA of a person with a
genetic disease or disorder by introducing working genes into the
nuclei of their cells

22. What is cloning? a technique that uses a single cell from an
adult organism to grow an entirely new individual that is
genetically identical to the organism from which the cell was taken

23. What is combined in nuclear transplantation? What is produced?
Name some species that have been created this way. an egg cell
with a donor nucleus; an embryo; cows, pigs, mice, cats