Question

Which protistan group show characteristics as presence of two types of nuclei, micronucleus and macronucleus?

• A. Sporozoa
• B. Ciliata
• C. Flagellata
• D. Sarcodina

Answer 1

The correct option is B Ciliata

The ciliated protozoa are the most conspicuous and easily recognized groups of protists. They are conspicuous, because they are usually motile and quite large, ranging from an average of about 50 micrometers up to 4 mm in size. They are easily recognized, because they are propelled through the water by hundreds to thousands of cilia that cover their bodies, aligned in long files or kineties. Ciliates have two kinds of nuclei and they are thus called heterokaryotic. The macronucleus as its name suggests is typically larger with sometimes thousands of copies of the genome. It is transcriptionally active (i.e., makes messenger RNA) and so controls cell functions and physiology. The micronucleus is smaller, usually diploid, and is the germ-line reserve, similar to the sperm and egg cell nuclei of multicellular organisms.