Is there a picture you forgot to post with the question?
In the problem you mention, which I assume comes from the study of finches in the Galapagos, some birds evolved to have different beaks, depending on the food available. Depending on what kind of seeds there are, different beak sizes were selected for, with those with the right fit eventually winning out over the rest on the individual islands.
A chloroplast is the organelles in which photosynthesis takes in plants. The chloroplast has thylakoid lamellae that occasionally arrange itself into stacks called grana where there are photosystem units that have chlorophyll pigment. The chlorophyll pigments tap energy from the photons of sunlight and use it for photophosphorylation.
