Section 9.1; Cellular Growth

1. Cells grow until they reach their size limit, then they either stop

growing or divide.

  1. The ratio of a cell’s surface area to cell volume determines the

limit of cell growth for cells.

  1. Cell size is limited by the cell’s ability to transport materials and

communicate instructions from the nucleus.

4. The cell cycle describes the process of cellular reproduction.

5. The cell cycle includes the normal cell functions and replication of

DNA (interphase), distribution of DNA (mitosis; and binary fission),

and cytokinesis.

6. A cell spends the majority of its lifetime in interphase.

Questions 9.1

1. Three hypothetical cells are each shaped as perfect cubes. The respective

length of the sides of each cell is 1 unit, 2 units, and three units. Complete the

following table.

1 unit / 2 units / 3 units
Surface area of the cell
Volume of the
cell
Ratio of surface area to volume

a. Which cell, 1, 2, or 3 units, has the greatest surface area to volume ratio?

b. Which cell, 1, 2, or 3, is most efficient transporting materials into, out of, and

inside the cell?

Typically, the cells have lengths measured in micrometers (μm). This is tiny…

2. Draw a circle representing the cell cycle. Label the following on the circle:

Interphase (G1, S, G2), Mitosis, and Cytokinesis.

Section 9.2; Mitosis and Cytokinesis

1. Eukaryotic cells divide their DNA in a process called mitosis, or nuclear division.

2. The four stages of mitosis are prophase, metaphase, anaphase, and telophase.

3. Cytokinesis divides the cytoplasm, and results in two genetically identical

daughter cells.

4. During cytokinesis, animal cells pinch in, and plants grow a cell plate and

split along the cell plate.

Questions 9.2

1. Sketch six circles arranged in a circle representing the cell cycle (p.249 will help).

2. Sketch, and label the four stages of mitosis, and label the significant structures.

3. In bullet form, describe what is happening in each stage of mitosis.

4. Repeat the same process for Interphase, and Cytokinesis.

5. Sketch and label how cytokinesis differs in animal and plant cells.

Section 9.3; Cell Cycle Regulation(p.246, 253, BINARY FISSION, WHEN A CELL REACHES ITS MAX. SIZE…)

1. The “normal” cell cycle is regulated by cyclin proteins.

2. Checkpoints occur during the cell cycle to ensure accuracy during replication.

3. Cancer is uncontrolled cell growth and uncontrolled division of cells.

4. Apoptosis is programmed cell death.

5. Stem cells are unspecialized cells that can develop into specialized cells

with the proper signals.

Questions 9.3

1. What is the name of a substance or agent that is known to “cause” cancer?

2. Give one example of when apoptosis occurs.

3. What is the difference between and embryonic and adult stem cell (beyond

the obvious answer please).