Question

which of the following is a characteristic of all cells? *
cell wall
cell membrane
chloroplasts
centrioles

what are the three main parts of the cell theory? *
your answer

Explanation:

1. All cells have a cell - membrane which acts as a barrier, controlling the movement of substances in and out of the cell. Plant cells and some prokaryotes have a cell wall, but animal cells do not. Chloroplasts are only present in plant cells and some protists for photosynthesis. Centrioles are mainly found in animal cells and are involved in cell division.
2. The three main parts of the cell theory are: all living organisms are composed of one or more cells; the cell is the basic unit of life; all cells come from pre - existing cells.

Answer:

1. B. Cell membrane
2. All living organisms are composed of one or more cells; the cell is the basic unit of life; all cells come from pre - existing cells.