Eighth Grade Activity: Cell Reprodcution

Cell Reproduction

Cell reproduction is the process by which a cell divides to form two or more daughter cells.  Each daughter cell will have its own genetic material.  Cell reproduction in human cells and most cells in nature including bacteria and plants takes place through either mitosis or meiosis.

Mitosis is the main reproduction process for most cells. In humans, there are 2 main types of cells: Somatic Cells (hair cell, skin cell, liver cell, stomach cell, bone cell, blood cell, etc.-anything not a sex cell) and sex cells (sperm cells and ova). Somatic cells divide by a process called mitosis. Sex cells divide by meiosis.

The Cell Cycle

When cells are not dividing, they are carrying out their normal processes; this is, a skin cell is providing protection or producing melanin, a stomach cell is producing acid, pesin or bicarbonate, a white blood cell is fighting foreign invading agents.

When cells are not dividing, they are in a stage called interphase. Interphase is made up of 3 stages: G1 phase, S phase and the G2 phase. By the end of interphase (G2 phase), cells are ready to divide and undergo processes of mitosis and cytokinesis.

Usually, when a cell divides, both its nucleus and its cytoplasm divide in two to provide enough material to each of the daughter cells produced. The process of nuclear division into two nuclei is called mitosis. The process of cytoplasm division into two is called cytokinesis. 

Mitosis

There are four main phases in mitosis, they are Prophase, Metaphase, Anaphase and Telophase, in that order.

                                                             

Mitosis Questions

In your notes, copy the questions and answer them.

1.      1.  Draw and describe what happens in each of the phases of mitosis.

2.       2. Define cell reproduction.

3.       3. What are the 2 main types of cells in humans?

4.       4. Provide 2 examples for somatic cells and 2 examples for sex cells.

5.       5. What is the process by which somatic cells reproduce?

6.       6. What is the process by which sex cells divide?

7.       7. What is interphase?

8.       8. What happens during each of the phases of interphase? (see figure)

9.       9. What is cytokinesis?

1010.   During which phase of mitosis, do the centrioles pull apart the chromosomes?