Question

the cell membrane is also called (select all that apply) cell wall fluid mosaic model plasma membrane phospholipid bilayer what is found in all cells and maintains homeostasis by controlling what enters and leaves the cell? cell wall nucleus cell membrane dna a researcher is studying a novel enzyme that breaks down a specific protein. the enzyme is found to be most effective within a narrow ph range of 8.0 to 8.5. what can be concluded about the environment in which this enzyme most likely functions? it functions best in a strong acidic environment. it functions best in a strong basic environment. it functions best in a weakly basic environment. it functions equally well in both acidic and basic environments which is not a part of the cell theory? all living things are made of one or more cells all cells have a nucleus cells are the basic unit of life all cells come from pre - existing cells

Explanation:

1. The cell membrane is a phospholipid bilayer and is part of the cell membrane structure. Cell walls are not present in all cells (e.g., animal cells lack cell walls). The fluid - mosaic model describes the cell membrane.
2. The cell membrane controls the movement of substances in and out of the cell, maintaining homeostasis. Not all cells have a nucleus (prokaryotes). DNA is genetic material, not a structure for controlling entry/exit.
3. A pH range of 8.0 - 8.5 is slightly above 7 (neutral pH), indicating a weakly basic environment. Enzymes have optimal pH ranges for activity.
4. The cell theory states that all living things are made of one or more cells, cells are the basic unit of life, and all cells come from pre - existing cells. Not all cells have a nucleus (prokaryotic cells).

Answer:

1. plasma membrane, phospholipid bilayer
2. cell membrane
3. It functions best in a weakly basic environment.
4. All cells have a nucleus.