Mitosis Review

Where is mitosis in the cell cycle?

Before Interphase and after Cytokinesis.

What three phases of the cell cycle are considered "interphase"?

G1, S, G2

a) How many cells are present at the end of G2?

1 cell

b) How many cells are present at the end of M?

2 cells

What shape do the replicated chromosomes look like in prophase of the original cell?

X-shaped

How many chromatids are in each replicated chromosome?

2 chromatids

How many replicated chromosomes are there in the original cell during prophase? (Hint: When counting chromosomes, count "1" for a pair of sister chromatids)

The same number as the original cell

How many single chromosomes are there in each of the new cells in telophase?

The same number as the original cell

During what phase of the cell cycle do you think the chromosomes are replicated (copied)?

S phase

Describe the difference in appearance between the chromosomes during prophase in the original cell and the chromosomes in the two new cells in telophase.

Prophase: X-shaped chromosomes; Telophase: Single chromosomes

Why do you think the cell needs to make more DNA during the S phase of the cell cycle?

To ensure each daughter cell receives a complete set of genetic information.

At what stage of mitosis do the replicated chromosomes (sister chromatids) separate?

Anaphase

During what phase do you see the spindle fibers forming?

Prophase

During what phase do you see that the spindle fibers have disappeared?

Telophase

What do you think the function of the spindle fibers is during mitosis?

Spindle fibers help separate replicated chromosomes during mitosis.

Describe what happens to the nuclear membrane after prophase.

Disintegrates/dissolves

Why do you think it is necessary to disintegrate the nuclear membrane during mitosis?

Facilitates the separation of chromosomes

By the end of what phase of mitosis has the nuclear membrane reformed?

Telophase

What structure reappears in the nucleus after cytokinesis?

Nucleolus

What is actually dividing during cytokinesis?

The entire cell

Explain why mitosis has to come before cytokinesis in the cell cycle.

Ensures each daughter cell receives a complete set of genetic material before physically dividing.

Why does DNA coil up into chromosome structures before it divides during mitosis?

Ensures orderly and equal distribution of genetic material during cell division.

Create a table listing each phase of cellular division and a word description of what is happening during that phase.

Prophase: Chromosomes condense and become visible; Metaphase: Chromosomes align at the cell's equator; Anaphase: Sister chromatids separate and move to opposite poles; Telophase: Chromosomes decondense, nuclear membrane reforms, and cytokinesis occurs.

In some cells, mitosis occurs WITHOUT cytokinesis. What would the resulting cell look like?

A cell with multiple nuclei

Explain the importance of mitosis in cells during a skinned knee and the growth of a plant.

Skinned knee: Mitosis repairs damaged cells; Plant growth: Mitosis produces new cells for growth.

Consider the effect on a cell if sister chromatids did not line up correctly during metaphase. How might this affect the resulting cells?

Unequal distribution of genetic material, leading to genetic abnormalities in daughter cells.