Final answer:
Chlorophyll is the pigment that gives plants their green color. It is located within the chloroplasts of leaf cells and plays a key role in photosynthesis by absorbing blue and red light and reflecting green light.
Step-by-step explanation:
The substance that gives plants their green color is a pigment known as chlorophyll. This pigment is crucial for the process of photosynthesis, during which plants capture solar energy to synthesize glucose from carbon dioxide and water. Chloroplasts, found in the cells of leaves, house the chlorophyll in a specific area of their structure called the thylakoid membranes.
Chlorophyll absorbs light primarily in the blue and red wavelengths and reflects the green wavelength, which is why plants appear green to our eyes. This ability to absorb light energy efficiently allows plants to use the energy to convert carbon dioxide and water into glucose and oxygen, sustaining their growth.
In addition to chlorophyll, plants contain other pigments like chlorophyll b and β-carotene, which can give leaves different colors when they mask the green of chlorophyll. However, chlorophyll is predominant and essential for capturing the energy necessary for photosynthesis.