The pseudopodia that are filamentous and contain central axis of microtubules is called________.
The correct answer and explanation is:
The correct answer is axopodia.
Axopodia are a type of pseudopodia found in certain protozoa, such as Actinosphaerium and Heliozoa. These are long, slender, and often radiate outward from the cell body. The most notable feature of axopodia is their structure: they contain a central axis of microtubules that helps to maintain their rigidity and extendability.
The microtubules are arranged in a bundle, with their ends embedded in the cytoplasm of the cell. These microtubules are crucial because they support the axopodium’s shape and enable it to be extended and retracted. The extension of axopodia is an energy-consuming process where the cell pushes its cytoplasm into the pseudopodium, and the microtubules provide structural support, preventing the extension from collapsing. This rigidity is essential for the axopodium’s function in movement and feeding.
Axopodia are used primarily in two ways: for capturing food and for locomotion. In some species, axopodia function in capturing small prey or detritus through a process called phagocytosis. The axopodia extend and then trap the prey, which is subsequently engulfed by the cell. Additionally, axopodia play a role in the movement of the organism by pushing or pulling the cell body along surfaces or through aquatic environments.
Axopodia differ from other types of pseudopodia, such as lobopodia and filopodia, in their structure and function. Lobopodia are more generalized and consist of a thicker, more irregular shape, while filopodia are slender and may not have the internal microtubule support that axopodia do.
In conclusion, axopodia are specialized, microtubule-supported pseudopodia that play critical roles in both movement and feeding in certain protozoan species.