Keystone Review – Characteristics of Life (Cells)
1. D – All the activities help keep the internal
conditions of a cell constant.
2. A – Both prokaryotes contain ribosomes that
assemble proteins from mRNA.
3. D – Prokaryotic cells are much smaller than
eukaryotic cells
4. D – The plasma membrane’s role is to
determine which substances can enter and
exit the cell
5. B – DNA is found in the nucleus in an
eukaryotic cell.
Keystone Review – Characteristics of Life (Cells)
A. Identify structure 1 and describe its main function.
Structure 1 is the cell wall, and its role is to support and
provide protection for the cell. For example, a plant cell
will not burst if it is place in a hypotonic environment.
Keystone Review – Characteristics of Life (Cells)
B. Identify structure and describe its main function.
Structure 3 is the central vacuole, and its role is to store
materials such as water and nutreints.
Keystone Review – Characteristics of Life (Cells)
C. A wilted houseplant is watered. Explain how
structures 1 and 3 work together to cause a change in
the plant.
A plant wilts because it lost water. When the plant is
watered, the water is stored in the central vacuole and
this organelle expands. This places pressure against the
cell wall, which remains rigid. This pressure within the
plant cell causes the plant to remain upright.