| A | B |
|---|
| What part of the cell forms a barrier between the cell and its environment? | cell membrane |
| What part of the cell keeps the cell membrane from collapsing? | cytoskeleton |
| Which of the following are found mainly in animal cells? | lysosomes |
| What are the four levels of organization in living things? | cell - tissue - organ - organ system |
| Which of the following best describes an organ? | a group of tissues that work together to perform a specific job |
| Human beings are | organisms |
| The life span of a multicellular organism is | not limited to the life of a single cell |
| A group of cells with the same function makes up | a tissue |
