Identify the mismatched pair from the following:

Identify the odd one out from the given groups based on their biological classification.

Which of the following organisms is/are correctly assigned to its/their taxonomic group?

Consider the following statements $(A-D)$:
$(A)$ Heterocysts are important sites for nitrogen fixation in $\text{BGA}$.
$(B)$ Cell wall of diatoms is indestructible due to presence of calcium carbonate.
$(C)$ In fungi,the cell wall is made up of chitin.
$(D)$ Algae show isogamous,anisogamous,and oogamous types of sexual reproduction.
How many of the above statement$(s)$ is/are not correct?

Assertion $A$: Slime molds are known as bread molds.
Reason $R$: The cell wall of molds is made up of cellulose.
Which option is correct for Assertion $A$ and Reason $R$?

In the $3$-domain system of classification,into which domain are prokaryotic and eukaryotic organisms divided?