Chapter 19, Problem 11A

Summary Introduction

To write:

About Pseudopod.

Introduction:

Structures in a living organism are either an extension of a cell, some kind of formation of different macromolecules (like proteins), or can be an arrangement of different cells that are aligned to perform a particular function. Different organisms are adapted to form different structures that help them to perform their life functions. Some structures may seem similar in different organisms but have different internal structures.

Explanation of Solution

Pseudopod is a structure generally seen in protozoa. Protozoa are animal-like protists that follow a heterotrophic mode of nutrition and are thus characterized as heterotrophs. Protozoans generally ingest other protozoans, algae, and bacteria to obtain energy and nutrition.

Pseudopod is a cytoplasmic extension and is a temporary structure formed in protozoans. This structure is generally used for motility and capturing food by organisms belonging to class Sarcodina of protozoa. The organism extends the cytoplasm in the direction where it wants to move or senses a prey. In the case of prey ingestion, the pseudopod surrounds the prey and forms an envelope like food vacuole around it. The prey is then digested in the food vacuole with the help of digestive enzymes. For motility, a new pseudopod is formed and the older one is retracted that helps in the movement of the organism. The formation of a pseudopod is generally seen in Amoeba.

Conclusion

A pseudopod is a temporary structure formed by the extension of the cytoplasm in Amoeba.