Explanation:

To determine the number of organisms that can have a motile asexual stage, let's analyze each organism mentioned in the example.

1. Diatom: Diatoms are a type of algae that have a hard, silica-based cell wall. They reproduce asexually by cell division. Diatoms do not have a motile stage, so they are excluded from the count.

2. Euglenoids: Euglenoids are a group of protists that have characteristics of both plants and animals. They possess a flagellum that enables them to move. Euglenoids can reproduce asexually through cell division and have a motile asexual stage.

3. Dinoflagellate: Dinoflagellates are a type of planktonic protist that possesses two flagella, which allow them to move. They can reproduce both sexually and asexually. However, their asexual reproduction involves the formation of cysts, which are not motile. Therefore, dinoflagellates are excluded from the count.

4. Trypanosoma: Trypanosoma is a parasitic protist that causes diseases like sleeping sickness and Chagas disease. It has a flagellum that aids in its mobility. Trypanosoma can reproduce asexually by binary fission, and its asexual stage is motile.

5. Agaricus: Agaricus is a type of mushroom that belongs to the fungi kingdom. Fungi reproduce sexually through the fusion of hyphae, which are thread-like structures. They do not have a motile asexual stage, so Agaricus is excluded from the count.

6. Ustilago: Ustilago is a genus of smut fungi that infects various plants. Like other fungi, Ustilago reproduces sexually by the fusion of hyphae. It does not have a motile asexual stage, so it is not included.

7. Albugo: Albugo is a genus of parasitic oomycetes that infects plants. Oomycetes are not true fungi but resemble them in many ways. Albugo reproduces sexually through the fusion of gametes and asexually through the production of spores. However, its asexual spores are non-motile, so Albugo is excluded from the count.

Summary:

Out of the organisms mentioned in the example, four can have a motile asexual stage: Euglenoids, Trypanosoma, Agaricus, and Ustilago. Diatom, Dinoflagellate, and Albugo do not have a motile asexual stage.

Only two