Understanding Dual Nutrition in Organisms

The question asks to identify the organism that displays both autotrophic and heterotrophic modes of nutrition. Let's break down what these terms mean:

• Autotrophic Nutrition: This is when an organism makes its own food, typically using light energy through photosynthesis. Think of plants and algae.
• Heterotrophic Nutrition: This is when an organism gets its food by consuming other organisms or organic matter. Most animals and fungi exhibit this.

Some organisms can switch between these modes depending on their environment. This is known as mixotrophy.

Analyzing the Options

Let's examine each option provided:

• Euglena: Euglena is a single-celled protist. It possesses chloroplasts and can perform photosynthesis in the presence of sunlight, making it autotrophic. However, when light is absent, it can absorb nutrients from its surroundings, behaving in a heterotrophic manner. This dual capability makes Euglena a classic example of mixotrophy.
• Paramecium: Paramecium is another single-celled protist. It lacks chloroplasts and cannot photosynthesize. It obtains nutrients by engulfing food particles like bacteria and algae from its environment, which is a purely heterotrophic mode of nutrition.
• Amoeba: Amoeba, like Paramecium, is a single-celled organism. It engulfs its food using pseudopods through a process called phagocytosis. This is a form of heterotrophic nutrition. It does not have the ability to photosynthesize.
• Plasmodium: Plasmodium is a parasitic protozoan that causes malaria. It lives inside the red blood cells of its host and absorbs nutrients directly from the host's blood. This is an obligate heterotrophic (specifically, parasitic) mode of nutrition.

Conclusion on Nutrition Modes

Based on the analysis, Euglena is the only organism listed that exhibits both autotrophic (photosynthesis) and heterotrophic (absorption) nutrition depending on environmental conditions.