Chapter 22, Problem 1SQ

Summary Introduction

To explain: Whether a large animal could rely solely on food vacuoles.

Introduction: Food vacuoles are formed as the cell engulfs food particles by forming a vacuole. It fuses with a lysosome for the digestion of enclosed food. The small molecules derived from the food vacuoles nourish the cell. However, as body organization and complexity increases, the organism requires a specialized digestive compartment where large food particle could be digested.

Answer to Problem 1SQ

No, the large animal could not rely solely on food vacuoles.

Explanation of Solution

Food vacuoles are a digestive system. The intracellular digestion of food material occur by hydrolysis. This commences when a cell swamps the solid food by phagocytosis or liquid food by pinocytosis. The food vacuoles merge with lysosomes which contain hydrolytic enzymes. This allows the digestion to proceed safely, in a protective compartment with hydrolytic enzymes. As the new, large species discovered rely on food vacuoles instead of the alimentary canal for food digestion, large food cannot be digested by the food vacuole. It would be difficult for the animal to eliminate the waste. The animal would not be able to nourish the many cells from which they are composed. Therefore, they require a special alimentary canal or digestive tract.