compare the process of digesting food in an amoeba to those in a mouse

Answer 1

The process of digesting food in an amoeba and a mouse differs mainly in terms of the complexity of their digestive systems. Here's a comparison:

1. Structural Differences:
- Amoeba: Amoebas are single-celled organisms, and they lack a distinct digestive system. They possess a cell membrane, cytoplasm, and a contractile vacuole that helps in expelling excess water.
- Mouse: Mice have a complex digestive system consisting of organs such as the mouth, esophagus, stomach, small intestine, large intestine, and anus. They also have accessory organs like the liver and pancreas.

2. Ingestion:
- Amoeba: Amoebas capture small food particles by extending their pseudopods (temporary cytoplasmic extensions) around the particle to form a food vacuole.
- Mouse: Mice use their mouth and specialized teeth to bite and chew food into smaller pieces, forming a bolus that can be easily swallowed.

3. Digestion:
- Amoeba: In amoebas, digestion occurs intracellularly within the food vacuole. It involves the secretion of enzymes that break down the captured food into simpler soluble substances.
- Mouse: Digestion in mice is both extracellular and intracellular. Digestive enzymes (such as amylase, proteases, and lipases) are secreted by various organs including salivary glands, stomach, pancreas, and small intestine. These enzymes break down complex carbohydrates, proteins, and lipids into simpler forms.

4. Absorption:
- Amoeba: Once the food is broken down into simpler forms within the food vacuole, it is absorbed directly through the cell membrane into the cytoplasm for further use.
- Mouse: After digestion in the various organs, the absorption of nutrients occurs primarily in the small intestine. The inner lining of the small intestine has finger-like projections called villi, which increase the surface area for absorption. Nutrients are absorbed into the blood vessels and lymphatics.

5. Egestion/Waste Elimination:
- Amoeba: Amoebas eliminate waste through the contractile vacuole, mainly expelling excess water and undigested particles through the plasma membrane.
- Mouse: Mice eliminate waste as undigested food through the rectum and anus in the form of feces.

In summary, amoebas have a relatively simple method of digestion, where digestion and absorption occur within the single cell. On the other hand, mice have a more complex digestive system, involving multiple organs and stages of digestion, leading to absorption of nutrients from the intestine.