Which of the following features is found in all protist lineages?

• A. Ability to photosynthesize
• B. Multicellularity
• C. Cell walls made of cellulose
• D. Presence of a nucleus (eukaryotic cells)

Answer: (D)

Verified step by step guidance

1. Understand the definition of protists: Protists are a diverse group of eukaryotic organisms that are not classified as plants, animals, or fungi. They can be unicellular or multicellular, and their characteristics vary widely.
2. Recognize the key feature of eukaryotic cells: All eukaryotic cells, including protists, have a nucleus. The nucleus is a membrane-bound organelle that contains the cell's genetic material (DNA).
3. Evaluate the other options: Not all protists have the ability to photosynthesize, as some are heterotrophic. Multicellularity is not a universal trait among protists, as many are unicellular. Cell walls made of cellulose are specific to certain plant-like protists, but not all protists possess this feature.
4. Identify the universal feature: The presence of a nucleus is the defining characteristic of all eukaryotic cells, including protists. This distinguishes them from prokaryotic organisms, which lack a nucleus.
5. Conclude that the correct answer is 'Presence of a nucleus (eukaryotic cells)' because it is the feature found in all protist lineages, regardless of their other diverse traits.