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 is a green pigment present in plants which facilitate the absorption of light from the sun. It has the ability to convert this light energy into a usable form which is utilized for various processes such as photosynthesis by virtue of which the green plants prepare their own food.