Amoeba is a unicellular organism that obtains its food through a process known as holozoic nutrition. Unlike multicellular organisms with specialized digestive systems Amoeba feeds using pseudopodia which are temporary finger-like projections of its body.
This topic explains the nutrition process in Amoeba covering ingestion digestion absorption assimilation and egestion. Understanding this process is important in Class 10 Biology as it helps explain how simple organisms obtain energy for survival.
What Is Holozoic Nutrition?
Holozoic nutrition is a type of nutrition where an organism ingests solid food digests it absorbs nutrients and eliminates waste. Amoeba follows this type of nutrition similar to animals but at a much simpler level.
Steps in the Nutrition Process of Amoeba
The nutrition process in Amoeba occurs in five main steps:
- Ingestion (Taking in food)
- Digestion (Breaking down food)
- Absorption (Nutrient uptake)
- Assimilation (Using nutrients for energy)
- Egestion (Removing waste)
Let’s explore each step in detail.
Step 1: Ingestion – How Amoeba Captures Food
Amoeba does not have a mouth or a fixed shape. Instead it captures food using pseudopodia which surround and engulf food ptopics. This process is called phagocytosis.
- Amoeba extends its pseudopodia toward the food ptopic (e.g. bacteria or algae).
- The pseudopodia surround the food and form a food vacuole enclosing the food inside its body.
Example of Ingestion
If an Amoeba encounters a small bacterium it stretches its pseudopodia around it trapping it inside a food vacuole.
Step 2: Digestion – Breaking Down Food
Once the food is inside the food vacuole Amoeba starts digesting it.
- Lysosomes release digestive enzymes into the food vacuole.
- These enzymes break down complex food ptopics into simpler absorbable nutrients.
- This process is similar to digestion in human stomachs but much simpler.
Example of Digestion
If Amoeba eats starch or protein enzymes break them down into simpler molecules like glucose and amino acids.
Step 3: Absorption – Taking in Nutrients
After digestion the simpler nutrients are absorbed into the cytoplasm of Amoeba.
- The digested nutrients pass through the membrane of the food vacuole into the cytoplasm.
- This absorbed food provides energy and materials for growth and repair.
Step 4: Assimilation – Using Nutrients for Energy
Once absorbed the nutrients are used for:
- Energy production through respiration.
- Growth by forming new cytoplasmic material.
- Reproduction by helping Amoeba divide and multiply.
The absorbed nutrients help Amoeba perform daily activities like movement feeding and responding to its environment.
Step 5: Egestion – Removing Waste
After digestion and absorption some undigested materials remain inside the food vacuole. These need to be removed from the body.
- The food vacuole moves toward the cell membrane.
- The waste is expelled out through a process called exocytosis.
- The remaining waste material is released into the surrounding water.
Example of Egestion
Any undigested food ptopics that Amoeba cannot use are expelled keeping the cytoplasm clean.
Why Is the Nutrition Process in Amoeba Important?
The process of nutrition in Amoeba is crucial because:
- It demonstrates a simple mode of feeding in unicellular organisms.
- It shows how life can exist without specialized digestive organs.
- It helps us understand how nutrients provide energy for survival.
Comparison: Amoeba vs. Human Digestion
| Feature | Amoeba | Humans |
|---|---|---|
| Type of Nutrition | Holozoic | Holozoic |
| Mode of Feeding | Pseudopodia (phagocytosis) | Mouth and digestive tract |
| Digestion | Inside food vacuole | Stomach and intestines |
| Enzymes | Lysosomal enzymes | Digestive enzymes (amylase pepsin etc.) |
| Egestion | Exocytosis | Anus |
The nutrition process in Amoeba is a fascinating example of how simple organisms survive. By using pseudopodia for ingestion and digesting food inside a food vacuole Amoeba efficiently absorbs nutrients and removes waste.
This process highlights the importance of unicellular organisms in nature and their ability to thrive without complex digestive systems. Understanding Amoeba’s nutrition helps students grasp fundamental biological concepts making it an essential topic in Class 10 Biology.
