Practice Set 7

Question 1

Transposons are useful in genetic analysis because of their use in

Answer 1

Gene tagging

Question 2

The blastocyst of a wild-type mouse is injected with cells heterozygous for a dominant mutation
for bent-tail. If this blastocyst develops into a mouse, and the mouse is crossed to wild-type, what
percentage of the baby mice will have bent-tail?

Answer 2

Answer: Can’t tell

Question 3

If you were making libraries of large genomes such as those of mammals, which of the following
vectors would you be the least likely to use?

Answer 3

lambda phage

Question 4

In a FISH analysis, a cloned probe of a single-copy gene hybridizes to cells in mitotic metaphase.
How many fluorescent spots will be seen in one cell?

Answer 4

4

Question 5

When a fertilized egg from a dwarf mouse (caused by a homozygous recessive mutation lit/lit)
was injected with a normal active rat growth-hormone gene, the resulting transgenic mouse was
normal-sized. This transgenic mouse was crossed to a lit/lit mouse. What proportion of baby mice are
expected to be normal-sized if only one copy of the transgene was injected?

Answer 5

1/2

Question 6

Transgenic plants can be generated using T-DNA plasmid carrying a gene of interest. To get the
DNA into the plant cells, the researchers

Answer 6

co-cultivate bacteria with T-DNA and plant cells, resulting in DNA transfer.

Question 7

Homologous recombination in yeast facilitates

Answer 7

the targeted replacement of a gene in a living yeast cell.