Cystic fibrosis results when patients Inherit two coples of a recessive CFTR gene. The recessive CFTR genes produce a protein which causes mucus to build up in parts of the body, Having just one
dominant CFTR gene allows the body to produce a normal protein, Individuals with one dominant
CFTR gene have no cystic fibrosis symptoms. Which question would BEST help researchers identify
a potential treatment for cystic fibrosis?

Why are small quantities of chlorofluorocarbons so harmful to the ozone layer? a. the chlorofluorocarbons act like ultraviolet radiation causing large amount of ozone to be produced. b. the chlorine from the chlorofluorocarbons reacts with free molecules of oxygen causing a stop in ozone production c. free oxygen atoms can replace the chlorine in chlorine monoxide, releasing a free atom of chlorine which can then recombine with an oxygen atom in ozone, destroying more ozone. d. chlorofluorocarbons absorb ultraviolet radiation, preventing the formation of ozone select the best answer from the choices provided

Astudent reads the following text in a science book: scientific evidence tells us that the cause of earths four seasons is the tilt of earth as it revolves around the sound the student is instructed to illustrate this information in a science book. how will the student illustrate winter in the northern hemisphere? a.earths northern hemisphere will tilt away from the sun. b. earths northern hemisphere will tilt toward the sun. c.earths orbit will be farther away than from the sun d. earths southern hemisphere will tilt away from the sun.

What is the term for the two sets of chromatids formed in the parent cell a.haploid b.diploid c.gamete d.tetrad