The substance (DCMUDCMU) is an herbicide that inhibits photosynthesis by blocking electron transfer between plastoquinones in photosystem II. Part A Would you expect DCMUDCMU to interfere with cyclic photophosphorylation?

No

Explanation:

During cyclic photophosphorylation, electrons are cycled continuously out of and back into the reaction center of PSI. It does not involve PSII and plastoquinone. During non cyclic photophosphorylation, the reaction center of plant photosystem II passes electrons to plastoquinone. The reduced plastoquinone carries electrons to the cytochrome b6f complex. Since PSII and plastoquinones are not included in cyclic photophosphorylation, would not affect the process.  

clumped distribution, because you'de have all of the population gathered in a relatively small are.

it's the most common because it provides protection and a mate for reproduction

example: humans, seeweed, cattles, etc.

the second type of galaxy is called a barred spiral, which has a thing called a bar straddling the nucleus