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I. Unicellular. Colonial, filamentous, m...

I. Unicellular. Colonial, filamentous, marine or terrestrial forms
II. The colonial , filamentous, marine or terrestrial forms
III. Some can fix atmospheric nitrogen in specialised cells called heterocysts
IV. They often form blooms in water bodies.
these above characters are seen in

A

Archaebacteria

B

Cyanobacteria

C

Chrysophytes

D

Dinoflagellates

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The correct Answer is:
To solve the question regarding the characteristics of certain organisms, we need to identify which group exhibits the listed traits. Let's break down the characteristics step by step: ### Step-by-Step Solution: 1. **Identify the Characteristics**: - The first characteristic mentions that the organisms can be unicellular, colonial, filamentous, and can exist in marine or terrestrial forms. - The second characteristic reiterates the colonial, filamentous, marine, or terrestrial forms. - The third characteristic states that some can fix atmospheric nitrogen in specialized cells called heterocysts. - The fourth characteristic notes that they often form blooms in water bodies. 2. **Analyze the Options**: - The options provided are: - A) Archaebacteria - B) Cyanobacteria - C) Chrysophytes - D) Dinoflagellates 3. **Evaluate Each Option**: - **Archaebacteria**: Generally, they are known for extreme environments and do not typically exhibit the characteristics mentioned. - **Cyanobacteria**: Known as blue-green algae, they are indeed unicellular, can form colonies and filaments, can live in both marine and terrestrial environments, can fix atmospheric nitrogen using heterocysts, and are known to form algal blooms in water bodies. - **Chrysophytes**: These are primarily golden algae and do not possess all the mentioned characteristics. - **Dinoflagellates**: While they can be marine and form blooms, they do not fix atmospheric nitrogen in the same way as cyanobacteria. 4. **Conclusion**: - Based on the analysis, the only group that matches all the characteristics outlined in the question is **Cyanobacteria**. ### Final Answer: The correct answer is **B) Cyanobacteria**. ---
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DINESH PUBLICATION ENGLISH-KINGDOM MONERA (THE PROKARYOTES)-REVISION QUESTIONS FROM CPMPETITIVE EXAMS.
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  13. The organisms which lack a cell wall and can live without oxygen are

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  14. Of the following statements which are not relevant to archaebacteria ...

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  16. Which part of the cell can contain N- acetylglucosamine

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  18. How many basal body rings are present in gram (+)ve cells

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