Why are Paramecium considered among the most complex of the protists?

• A. They lack any internal organelles.
• B. They possess specialized organelles such as cilia, contractile vacuoles, and two types of nuclei.
• C. They are capable of photosynthesis like plants.
• D. They reproduce only through binary fission.

Answer: (B)

Verified step by step guidance

1. Understand the classification of Paramecium: Paramecium are single-celled eukaryotic organisms belonging to the protist group. They are known for their complexity compared to other protists.
2. Examine the presence of specialized organelles: Paramecium possess unique structures such as cilia (used for movement and feeding), contractile vacuoles (used for osmoregulation), and two types of nuclei (a macronucleus for everyday functions and a micronucleus for reproduction). These organelles contribute to their complexity.
3. Compare Paramecium to other protists: Unlike simpler protists, Paramecium have a higher degree of specialization in their organelles, allowing them to perform complex functions such as locomotion, feeding, and maintaining internal balance.
4. Clarify the incorrect options: Paramecium do not lack internal organelles; they have specialized ones. They are not capable of photosynthesis like plants, as they are heterotrophic and feed on microorganisms. While they reproduce through binary fission, they can also engage in conjugation, a form of genetic exchange, adding to their complexity.
5. Conclude why Paramecium are considered complex: The presence of specialized organelles and their ability to perform diverse functions make Paramecium one of the most complex protists.