Question

Question 19 of 50 > When cloning a foreign DNA fragment into a plasmid, it is often useful to insert the fragment at a site that interrupts a selectable marker (such as the tetracycline-resistance gene of PBR322). The loss of function of the interrupted gene can be used to identify clones containing recombinant plasmids with foreign DNA. With a yeast artificial chromosome (YAC) vector, a researcher can distinguish vectors that incorporate large foreign DNA fragments from those that do not, without interrupting gene function. How are the recombinant vectors in a YAC typically identified? The YAC vector contains a gene that confers antibiotic resistance: vectors containing foreign DNA will grow on a plate containing this antibiotic. The gene encoding P-galactosidase becomes inactive due to insertion of foreign DNA, so colonies grown on an ngar plate containing X-gal appear white instead of blue, The YAC vector contains a screenable marker that encodes for a protein that causes the cell to produce an easily identifiable fluorescent molecule. The two parts of a YAC vector contain two selectable markers that are not interrupted by the foreign DNA, and both must be present for the cell to survive on the selective medias Which of these is not a risk associated with GMO foods? Heavy government regulation will drive up the price of modified food crops for consumers. O Loss of genetic diversity in crops may make them more vulnerable to discase. Pests that we want to kill may becomeresistant to insect-killing Bt crystals in modified crops. Organisms that are not considered pests may inadvertently be killed by insect-resistant, genetically modified crops. There may be unknown costs that offset the apparent financial advantages of raising modified crops.

Answer 1

Okay, here are the answers:

19. The YAC vector contains a screenable marker that encodes for a protein that causes the cell to produce an easily identifiable fluorescent molecule.

Risks associated with GMO foods (question 20 options):

O Loss of genetic diversity in crops may make them more vulnerable to discase.

Pests that we want to kill may becomeresistant to insect-killing Bt crystals in modified crops.

X Organisms that are not considered pests may inadvertently be killed by insect-resistant, genetically modified crops.

There may be unknown costs that offset the apparent financial advantages of raising modified crops.

The option "Heavy government regulation will drive up the price of modified food crops for consumers." is not a risk associated with GMO foods.

Government regulation adding cost is an economic argument, whereas the other options discuss environmental or ecological risks from GMO foods.

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