A single gene could be inserted into a plant's genome, enabling specific traits to be expressed easily. Scientists have identified genes for two enzymes needed to make pro-vitamin A. One of these genes comes from corn.
I think it is D. You experience increase in breathing rate to obtain more oxygen which is delivered to cells through the bloodstream
<em>A circadian rhythm /sɜːrˈkeɪdiən/ is any biological process that displays an endogenous, entrainable oscillation of about 24 hours. These 24-hour rhythms are driven by a circadian clock, and they have been widely observed in plants, animals, fungi, and cyanobacteria.</em>
the correct answer is a)I only
I believe the answer is that the CFCs cause low ozone concentrations in the atmosphere.
Sorry if I'm wrong, hope this helps.