The correct option is:
Yeast lacks a membrane-bound nucleus. The onion skin cell has one.
Yeast cells are unicellular fungi and are classified as prokaryotic because they do not have a membrane-bound nucleus. In contrast, onion skin cells are eukaryotic cells, which do have a membrane-bound nucleus.
The other options are incorrect:
- Yeast does have a cell membrane.
- Yeast does have a cell wall, and onion skin cells also have a cell wall (made of cellulose).
- Yeast cells generally do not have chloroplasts, as they are not photosynthetic, and onion skin cells typically do not have chloroplasts either, as they are part of the plant's epidermis.
So, the key difference relevant to the options provided is the presence of a membrane-bound nucleus.