The organisms that have silicious cell walls and can produce domoic toxinsGroup of answer choicesSpirogyraDiatomsDinoflagellatesChlamydomonasCyanobacteriaNext

To determine which organisms have silicious cell walls and can produce domoic toxins, let's analyze the provided options:

1. Spirogyra: This is a green algae that has a cell wall made of cellulose, not silica.

2. Diatoms: These organisms have a distinctive silica (silicon dioxide) cell wall called a frustule. Moreover, some species of diatoms can produce domoic acid, which is a type of neurotoxin.

3. Dinoflagellates: While some dinoflagellates can produce toxins, their cell walls are primarily composed of cellulose and other organic materials rather than silica.

4. Chlamydomonas: This is another type of green algae with a cell wall made of cellulose.

5. Cyanobacteria: These are bacteria that typically have peptidoglycan in their cell walls and do not produce domoic toxins.

Based on this analysis, the correct answer to the question is:

Final Answer

Diatoms