Question

autotrophs
definition\tcharacteristics
organisms that can produce their own food using energy from sunlight or chemicals.\t
examples\tnon-examples
\t

Explanation:

To fill the table for autotrophs (a concept in Biology, a subfield of Natural Science):

Characteristics:

• Autotrophs are the producers in ecosystems. They convert inorganic substances (like \( \text{CO}_2 \), water) into organic food (e.g., glucose) via processes like photosynthesis (using sunlight, e.g., in plants) or chemosynthesis (using chemical energy, e.g., in some bacteria). They form the base of food chains as they don’t depend on other organisms for food.

Examples:

• Plants: Most green plants perform photosynthesis, using chlorophyll to capture sunlight, \( \text{CO}_2 \), and water to make glucose (\( \text{C}_6\text{H}_{12}\text{O}_6 \)) and oxygen (\( \text{O}_2 \)): \( 6\text{CO}_2 + 6\text{H}_2\text{O} \xrightarrow[\text{Chlorophyll}]{\text{Sunlight}} \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \).
• Algae: Aquatic autotrophs (e.g., green algae) also photosynthesize.
• Chemosynthetic Bacteria: Like those near hydrothermal vents, they use chemical energy (e.g., from hydrogen sulfide, \( \text{H}_2\text{S} \)) to produce food, e.g., \( \text{CO}_2 + 4\text{H}_2\text{S} + \text{O}_2

ightarrow \text{CH}_2\text{O} + 4\text{S} + 3\text{H}_2\text{O} \) (simplified chemosynthesis).

Non - Examples:

• Animals: All animals (e.g., humans, lions, fish) are heterotrophs—they must consume other organisms (plants, animals, or both) for energy and nutrients.
• Fungi: Mushrooms, yeasts, and molds are heterotrophs (often decomposers or parasites) that absorb nutrients from organic matter or other organisms.
• Most Bacteria (Heterotrophic): Bacteria that cause disease (e.g., \( \text{Streptococcus} \)) or decompose organic waste rely on external food sources.

Answer:

(Filled Table):

Definition	Characteristics
Examples	Non - Examples
- Plants (e.g., trees, grasses) <br> - Algae (e.g., green algae) <br> - Chemosynthetic bacteria (e.g., bacteria near hydrothermal vents)	- Animals (e.g., humans, lions) <br> - Fungi (e.g., mushrooms, yeasts) <br> - Heterotrophic bacteria (e.g., \( \text{Streptococcus} \))