You are given an unknown organism to identify. It is unicellular and heterotrophic. It is motile, using many short extensions of the cytoplasm, each featuring the 9+2 filament pattern. It has well-developed organelles and two nuclei, one large and one small. This organism is most likely to be a member of which group

A) radiolarians

B) slime molds

C) ciliates

D) kinetoplastids

E) foraminiferans

Answer: C) ciliates.

Explanation: Ciliates possess two different nuclei a diploid micronucleus which carry the germline of the cell. It also has a large, polyploid macronucleus which can be termed the vegetative nucleus, it takes care of general cell regulation, it expresses the phenotype of the organism. The macronucleus is generated from the micronucleus. The micronucleus passes the genetic material to offspring, but it does not express its genes. The macronucleus provides the small nuclear RNA for vegetative growth.

C-Ciliates

Explanation:

These are motile protozoan, with short, large number of organs of locomotion called Cilia. These cilia move up and down in various pattern in their aquatic in habitat.

The two nuclei are the generative nucleus which is concerned with the transmission of hereditary materials, and the larger Vegetative nucleus that coordinate expression of the phenotype traits and regulation of cell activities.

The 9+2 filament pattern of the cilia refers to the arrangement of the microtubules that made up the cilia. Figure 9 refer to the cylindrical arrangement of 9 fused miroctubles found at the outer layer of Cilia, while the other 2 microtubules which are not fused, occupy the center of the fused mircrotubules. This represent fig 2. Therefore outer 9 plus inner 2, gives 9+2 filament pattern. This arrangement makes cilia to have different undulation.