A Level Biology Practice Exam

What type of organisms primarily engage in photosynthesis?

1. Heterotrophic organisms

2. Autotrophic organisms

3. Aerobic organisms

4. Prokaryotic organisms

The correct answer is: Autotrophic organisms

The correct answer is that autotrophic organisms primarily engage in photosynthesis. Autotrophs, such as plants, algae, and some bacteria, are capable of producing their own food by converting light energy (usually from the sun) into chemical energy in the form of glucose through the process of photosynthesis. This process involves the absorption of carbon dioxide and water, utilizing sunlight to create organic compounds and release oxygen as a byproduct. Heterotrophic organisms, on the other hand, obtain their energy and nutrients by consuming other organisms, which means they do not engage in photosynthesis. Aerobic organisms refer to those that require oxygen for survival, and while many aerobic organisms are heterotrophs, not all photosynthetic organisms are necessarily aerobic. Prokaryotic organisms include a diverse group that can be autotrophic (like cyanobacteria, which photosynthesize) as well as heterotrophic, meaning that this category is too broad to specifically define those that engage in photosynthesis.