The question asks to identify organisms that are classified as producers in an ecosystem. Producers are organisms that can create their own food, forming the base of the food chain.
B) Green plants and certain bacteria that synthesise food. These organisms are capable of producing their own organic food from inorganic substances, primarily through photosynthesis (green plants) or chemosynthesis (certain bacteria), thus acting as the foundation of the food web.
The question asks to identify the biological process by which green plants convert solar energy into chemical energy. We need to recall the fundamental processes in plant biology and their definitions.
The overall chemical equation for photosynthesis is:
\[ 6\text{CO}_2 + 6\text{H}_2\text{O} + \text{Light Energy} \rightarrow \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \]C) Photosynthesis — Photosynthesis is the process used by green plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's metabolic activities. This chemical energy is stored in carbohydrate molecules, such as sugars, which are synthesized from carbon dioxide and water.
The question asks to identify which organism among the given options is NOT a producer in an ecosystem. To answer this, we need to understand the definition of a producer in an ecological context and then classify each option accordingly.
C) Zooplankton — Zooplankton are heterotrophic organisms that feed on phytoplankton (producers) and other zooplankton. They are primary or secondary consumers in an aquatic food web, not producers.
The question asks to identify the dominant primary producers in aquatic ecosystems. Primary producers are organisms that produce their own food, usually through photosynthesis, forming the base of the food web. We need to evaluate each option based on this definition in an aquatic context.
B) Phytoplankton are microscopic photosynthetic organisms that float in water. They are the primary producers in most aquatic food webs, converting sunlight into energy and forming the base upon which almost all other aquatic life depends. They are responsible for a substantial portion of global primary production.
The question asks why chemosynthetic bacteria act as producers. Producers are organisms that create their own food, typically through photosynthesis or chemosynthesis. We need to identify the characteristic that defines chemosynthesis.
Correct Option: C) Derive energy from oxidation of inorganic chemicals
Chemosynthetic bacteria are unique producers because they do not rely on sunlight. Instead, they obtain energy by oxidizing inorganic chemical compounds, such as hydrogen sulfide \((H_2S)\) which is abundant near hydrothermal vents. This energy is then used to synthesize organic molecules (food) from carbon dioxide, making them primary producers in these deep-sea ecosystems.
The question asks to identify the term for animals that feed exclusively on plants. This requires knowledge of basic ecological classifications of organisms based on their dietary habits.
Correct Option: D) Herbivores are animals that feed exclusively on plants. Examples include cows, deer, and rabbits.