Final answer:
The Kingdom Plantae is comprised of organisms that can perform photosynthesis, a process of converting sunlight into glucose for energy.
Step-by-step explanation:
All organisms in the Kingdom Plantae can perform photosynthesis. This process captures the energy of sunlight to convert carbon dioxide from the air and water into glucose, a type of sugar that provides energy and cellular respiration for the plant. Plants, algae, and certain bacteria called cyanobacteria are the only organisms capable of photosynthesis because they possess an organelle called chloroplasts, which is where photosynthesis occurs.
These organisms are known as photoautotrophs because they make their own food using the energy of light. In contrast, organisms such as animals, fungi, and most other bacteria are heterotrophs, as they are unable to perform photosynthesis and must rely on consuming other organisms or organic substances for energy.