Your analysis of your evidence is the most important part of your response essay. It is important that you do not simply restate your evidence or your thesis when constructing analysis. Instead, you should look to explain how the author's technique or use of a character, for example, adds to the theme conveyed.
Land plants (and plants in the ocean, called algae) have a lot of chlorophyll-a pigment because it is essential to photosynthesis, but they also have other pigments, called accessory pigments, that help them absorb light.
Chlorophyll uses the energy from the sun, along with water and carbon dioxide, to produce chemical energy in a process called photosynthesis. Photosynthesis takes place in a part of plants' cells called chloroplasts, which are most plentiful in plants' leaves.