Different Types of Pseudopods

Flagellated forms, which may be gametes, have been described in several genera. Plankton are the diverse collections of organisms that live in the water column of large bodies of water and are unable to swim against a current. Examples: Actinophrys sol is a common species often referred to as the ______.

Acanthocystis turfacea is a similar species commonly called the green ______ because its body is colored by harmless symbiotic green algae (zoochlorellae).

______ species are multinucleate, often reaching a diameter of 1 mm (0.04 inch).

Class Radiolaria: Characteristics: found in the upper layers of all oceans. Radiolarians, which are mostly spherically symmetrical, are known for their complex and beautifully sculptured, though minute, skeletons, referred to as ______.

Usually composed of silica, the test is elaborately perforated in a variety of patterns, forming a series either of latticelike plates or of loose needle-shaped ______.

Pseudopodia extend through the perforated skeleton. A chitinous central capsule encloses the nuclei and divides the cytoplasm into two zones. The outer cytoplasm contains many vacuoles that control the organism’s buoyancy. Asexual reproduction is by budding, binary fission, or multiple fission. Generally, the skeleton divides, and each daughter cell regenerates the missing half. In some cases, however, one daughter cell escapes and develops an ______.

The endoplasm, which contains the nuclei and various other organelles, is often brown, red, or black. The ectoplasm contains the digestive vacuoles. The cell is provided with axopodia that are stiffened by a central axis (axoneme). Their distinguishing features are: (1) a skeleton of strontium sulfate (SrSO4), or celestite (2) cell body covered with an outer pellicle, the periplasmic cortex and (3) the myonemes, contractile filaments grouped around the spicule. The contractile vacuoles are ______. They reproduce asexually by binary fission and sexually by isogamy. Examples: Amphilonche, Acanthochiasma.

Class Heliozoa: Characteristics: Heliozoans are spherical and predominantly freshwater and are found either floating or stalked. The body consists of two parts: an outer cortex containing food and contractile vacuoles, and an inner medulla containing one or many nuclei and the base of axopods. They are frequently enveloped by a shell (or test) composed of silica or organic material secreted by the organism in the form of scales or pieces in a gelatinous covering. The secretions exhibit a wide variety of shapes, which may help in species identification. The numerous radiating cytoplasmic masses, called pseudopodia (axopodia), are used more for capturing food than for locomotion. Heliozoans ingest protozoans, algae, and Actinophrys sol other small organisms and reproduce asexually by binary fission or by budding, or sexually by ______.

A distinguishing feature of actinopods is the presence of axopodia that are stiffened by a central axis called ______.

Actinopods reproduce asexually by ______ fission.

The endoplasm of actinopods may be colored brown, red, or black, while the ectoplasm contains ______ vacuoles.

The body of actinopods consists of an outer cortex and an inner medulla, with the base of axopods located in the ______.

Reticulose pseudopods are pseudopods in which individual pseudopodia blend together and form irregular meshes. Filopodium: a slender filamentous pseudopodium with a pointed end, brnched or unbranched, consisting mostly of ______.

Axopodia are specialized in phagocytosis with long, thin pseudopods supported by complex microtubule arrays enveloped with ______, and they respond rapidly to physical contact.

Actinopods have a rigid and beautiful structure. Many of them have a siliceous (glassy) shell, and float in the water column of the ocean. They are considered amoeboid because slender pseudopodia called axopodia extend from the shell and capture small organisms. Then a conveyor belt-like flow of ______ brings the trapped organisms into the center of the cell.

Axopodia remain stiff because they have an elaborate cytoskeleton of ______.

Class Acantharia are planktonic, free-living, exclusively marine protozoa, ranging in size from 0.05-5 mm in diameter. The cell consists of a central endoplasm and a peripheral ectoplasm (calymma), separated by a membrane - the central capsule which is perforated by ______.

Lopopodium: a short, blunt, broad pseudopod typical of amoeba. Actinopods have a rigid and beautiful structure. Many of them have a siliceous (glassy) shell, and float in the water column of the ocean. They are considered amoeboid because slender pseudopodia called axopodia extend from the shell and capture small organisms. Then a conveyor belt-like flow of ______ brings the trapped organisms into the center of the cell.