An amoeba moves by pushing out small projections called ______ and then pulling the rest of the organism along. A. pseudopodia B. pellicles C. bacterial conjugates D. spores
The correct answer and explanation is:
The correct answer is A. pseudopodia.
Amoebas are fascinating single-celled organisms known for their unique method of movement and feeding, which involves the use of structures called pseudopodia. The term pseudopodia means “false feet” in Greek, and it perfectly describes these temporary projections of the cell’s cytoplasm. To move, an amoeba extends a pseudopodium by flowing its cytoplasm forward in one direction. This creates a bulge or projection on the cell’s surface. Once the pseudopodium extends, the rest of the cell’s body flows into this projection, effectively pulling itself forward. This process is known as amoeboid movement and is not only crucial for locomotion but also for feeding.
The ability to form pseudopodia allows the amoeba to engulf food particles through a process called phagocytosis. When an amoeba encounters food, like a smaller organism or organic matter, it extends its pseudopodia around the particle, eventually enclosing it within a food vacuole. Inside this vacuole, enzymes break down the food for digestion. This method of feeding is very efficient for survival in various environments.
The other options listed do not relate to how amoebas move. Pellicles are structures found in some protozoans like euglenas, providing shape and flexibility but not involved in movement through projection. Bacterial conjugates refer to a process where bacteria exchange genetic material through a pilus, unrelated to amoeba movement. Spores are reproductive structures in fungi, plants, and some protozoa but do not describe the movement mechanism of amoebas.
The pseudopodial movement is an excellent example of how simple organisms adapt to their surroundings. By using this method, amoebas can navigate through watery environments, hunt food, and avoid unfavorable conditions, showcasing a remarkable adaptation for a single-celled life form.