Question

The sun Animalcules comes under the group----
(a)Foraminifera
(b) Heliozoa
(c) Radiolaria
(d)Testacea

Answer 1

Hint: Animalcule is an older term for a microscopic animal or protozoan. Sun Animalcule is a common name given to microbial eukaryotes with stiff arms or axopodia. They are termed as sun Animalcule because their axopodia look like beams of light coming from the sun. They are similar to Radiolaria.

Complete answer:
Heliozoa, commonly known as sun-animalcules, are microbial eukaryotes with stiff arms, radiating from their spherical bodies, which are responsible for their common name. The axopodia are microtubule-supported projections from the amoeboid cell body. They are used for capturing food, sensation, movement, and attachment. They may be found in both freshwater and marine environments. They are similar to Radiolaria, but they are distinguished from them by lacking central capsules and other complex skeletal elements, although some produce simple scales and spines. Heliozoans are spherical and are found either floating or stalked. They are frequently enveloped by a shell composed of silica or organic material secreted by the organism in the form of scales or pieces in a gelatinous covering. Heliozoans ingest protozoans, algae, and other small organisms and reproduce asexually by binary fission or by budding. Flagellated forms, which may be gametes, have been described in several genera.

Additional Information: -Heliozoa is regarded as a descriptive term applying to various lines of protists.
-Sun animalcules are members of the family Actinophryidae. This group comprises two genera: Actinophrys and Actinosphaerium.
- Actinophrys possesses a spherical shape and radiating pseudopodia called axopodia.
So, the correct answer is 'Heliozoa'

Note: -These protists have one nucleus located in the cell center. It has many false feet, that are attached by their bases to the nuclear membrane surface and protrude to the outside.
-These pseudopodia are supported by axial rods. Its axopodia have a number of indistinct extrusomes.
- These are special organelles for capturing or killing prey and for protection from its predators, which flow along its arms.