Amoebas with stiff pseudopods and silica shells are ___________.

Verified step by step guidance

1. Identify the key characteristics described: amoebas with stiff pseudopods and silica shells.
2. Recall that pseudopods are extensions of the cell used for movement and feeding, and their stiffness can indicate a specific group of amoebas.
3. Understand that silica shells refer to a hard, protective outer covering made of silicon dioxide, which is a distinctive feature.
4. Connect these features to known groups of amoebas; those with stiff pseudopods and silica shells belong to the group called 'Radiolarians'.
5. Conclude that the blank should be filled with 'Radiolarians', as they are amoebas characterized by stiff pseudopods and silica-based skeletons.

Key Concepts

Amoebas and Pseudopods

Amoebas are single-celled protists that move and feed using extensions called pseudopods. These pseudopods are temporary projections of the cell's cytoplasm, which can be flexible or stiff depending on the species, aiding in locomotion and capturing food.

Silica Shells in Protists

Some protists produce protective outer coverings made of silica, a hard, glass-like substance. These silica shells provide structural support and protection, and are characteristic of certain groups like diatoms and radiolarians.

Heliozoans

Heliozoans are a group of amoeboid protists known for their stiff, radiating pseudopods and silica-based skeletons. They use these stiff pseudopods for capturing prey and maintaining shape, distinguishing them from other amoebas with flexible pseudopods.