Which statement describes an example of gene therapy?
a. a virus is used to transfer human dna into a bacterial cell.
b. a defective gene is replaced with a normal gene.
c. dna banding patterns are used to identify an individual.
d. the genes for a certain desirable trait are identified.

There is a liquid capsule inside a cup full of liquid. the cup full of liquid has salt in it and the liquid capsule has no salt in it. in which direction will the solvent flow? a. the salt does not have to move b. from the capsule to the larger cup c. equally between the capsule and the cup d. from the larger cup to the capsule

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?

Match the pollutants. 1. a chlorofluorocarbon smoke 2. a biodegradable organophosphate insecticide freon 3. particle pollution paint 4. hazardous waste monoxide 5. carbon is completely burned malathion 6. carbon is incompletely burned dioxide