Answer the Following (Multiple Choice): What is the best definition of an herbicide?
a.) A chemical that takes the place of sunlight in photosynthesis.
b.) A chemical that speeds up photosynthesis in the chloroplast.
c.) A chemical that kills or slows down the growth of target plants.
d.) A chemical that promotes the growth of target plants.

Atrazine kills the plant because:
a.) It makes photosystem II send too many electrons to the electron transport chain.
b.) All of the other components of photosynthesis depend on the electrons from photosystem II.
c.) It forces the plant to make too many sugar building blocks
d.) The ATP synthase turns the atrazine into carbon dioxide.

If an herbicide steals electrons from photosystem I, it will prevent it from:
a.) forming oxygen
b.) forming NADPH
c.) forming NADP+
d.) Forming ATP

If an herbicide prevents the buildup of protons by the electron transport chain, which component will no longer be able to carry out its function?
a.) ATP synthase
b.) Photosystem II
c.) Oxygen
d.) water

If an herbicide shuts down the Calvin Cycle (light-independent reaction), what will be the consequence for the plant?
a.) The chlorophyll won’t be able to absorb light energy
b.) The plant won’t be able to break down sugars and produce carbon dioxide
c.) The plant won’t be able to produce the sugars needed for plant growth
d.) The plant will continue to grow as normal because it will have plenty of energy from the ATP synthase.