Which of the following did all protocells have in common?

• A. A surrounding membrane that separated internal contents from the environment
• B. A fully functional nucleus containing DNA
• C. Complex organelles such as mitochondria
• D. The ability to perform photosynthesis

Answer: (A)

Verified step by step guidance

1. Understand the concept of protocells: Protocells are simple, primitive structures hypothesized to be precursors to modern cells. They are not fully developed cells and lack complex organelles or a nucleus.
2. Identify the key feature of protocells: Protocells are thought to have had a surrounding membrane, which is essential for separating internal contents from the external environment and maintaining homeostasis.
3. Eliminate options that require advanced cellular structures: Protocells did not have a fully functional nucleus containing DNA or complex organelles like mitochondria, as these are features of more evolved eukaryotic cells.
4. Consider the ability to perform photosynthesis: Photosynthesis is a complex biochemical process requiring specialized structures like chloroplasts, which protocells did not possess.
5. Conclude that the common feature of all protocells was a surrounding membrane, as this is the simplest and most fundamental characteristic necessary for the formation of life-like structures.