All of the substances are which cause inheritable changes in genetic material.
a) agents
b) mutagens
c) pathogens
d) vectors

B) mutagens

Explanation:

Mutagenic substance is any substance that can cause mutations in a cell. In other words, when a cell is exposed to a mutagenic substance, that substance has the power to cause changes in the genetic material that are not repaired by the repairing enzymes and become inheritable characteristics, that is, it causes mutations that are inherited.

These substances can be divided into three types: chemical agents, physical agents and biological agents.

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."

after a the power stroke, adp is released, but the cross-bridge formed is still in place. atp then binds to myosin, moving the myosin to its high-energy state, releasing the myosin head from the actin active site.