Which of the following components is not used by both plants and cyanobacteria to carry out photosynthesis? a. carbon dioxide b. chlorophyll c. chloroplasts d. water
The correct answer and explanation is:
The correct answer is c. chloroplasts.
Explanation:
Plants and cyanobacteria both carry out photosynthesis to convert light energy into chemical energy, but they have differences in their cellular structures. Chloroplasts are the organelles responsible for photosynthesis in plants and algae. They contain chlorophyll, the pigment that absorbs light energy, and other enzymes that help convert carbon dioxide and water into glucose and oxygen. However, cyanobacteria, which are prokaryotic organisms, do not have chloroplasts because they lack membrane-bound organelles. Instead, cyanobacteria carry out photosynthesis in structures called thylakoids, which are part of the cell membrane and contain chlorophyll.
Both plants and cyanobacteria use carbon dioxide and water as raw materials in photosynthesis. Water is split during the light-dependent reactions, releasing oxygen as a byproduct, and carbon dioxide is fixed into an organic molecule in the Calvin cycle during the light-independent reactions.
Chlorophyll, the pigment that absorbs sunlight, is also common to both plants and cyanobacteria, enabling them to capture light energy and begin the process of photosynthesis. Without chlorophyll, the organisms would not be able to absorb sufficient light energy to power the necessary reactions.
In summary, while both plants and cyanobacteria utilize carbon dioxide, water, and chlorophyll to perform photosynthesis, only plants contain chloroplasts for this process. Cyanobacteria perform photosynthesis in thylakoid membranes, which serve the same function as chloroplasts but are located within the cell membrane.