Cell Biology Mitosis Quiz

Questions and Answers

List the four phases in the mitosis process.

Telophase, Metaphase, Prophase, Anaphase

Where is mitosis in the cell cycle (Before and after)?

(Before): G1/cytokinesis (After): G2/S(ynthesis)

What three phases of the cell cycle are considered interphase?

G1, G2, S

How many cells are present at the beginning of mitosis?

one Signup and view all the answers

How many cells are present at the end of mitosis?

two Signup and view all the answers

How many chromatids are in each replicated chromosome?

two sister chromatids Signup and view all the answers

How many replicated chromosomes are in the original cell during prophase?

four Signup and view all the answers

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

four each Signup and view all the answers

What is a chromosome and why is it important?

A chromosome is made of DNA wrapped around proteins and contains all the genetic information for an organism. Signup and view all the answers

What might the new cells in telophase contain if replication of chromosomes did not occur before cytokinesis? Would cells be viable?

The new cells might only contain half the original number of chromosomes. They would not be viable. Signup and view all the answers

Why do you think the cell needs to make more DNA during the S(ynthesis) phase in the cell cycle?

The cell must copy the chromosome material to ensure there is enough to make two new cells with the correct chromosome number. Signup and view all the answers

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

Synthesis Signup and view all the answers

In which phase of mitosis do you see the spindle fibers forming?

Prophase Signup and view all the answers

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

Anaphase Signup and view all the answers

In which phase do you see that the spindle fibers have disappeared?

Telophase Signup and view all the answers

Suggest the purpose of the spindle fibers during mitosis.

The spindle fibers separate the replicated chromosomes and move each single chromosome to the opposite sides of the cells. Signup and view all the answers

Describe what happens to the nuclear membrane after prophase.

It breaks down. Signup and view all the answers

Explain why it is necessary that the nuclear membrane disintegrates during mitosis.

It must be temporarily removed for the chromosomes to be divided into two cells. Signup and view all the answers

At what point during mitosis has the nuclear membrane reformed?

Telophase Signup and view all the answers

What is actually dividing during cytokinesis?

Cytoplasm Signup and view all the answers

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

The contents of the nucleus must be duplicated and the chromosomes must be correctly divided before the actual cell can divide into two new cells. Signup and view all the answers

Why does the DNA have to coil up into chromosome structures before it divides?

If they're long and thin, pieces of DNA can be lost. Signup and view all the answers

Describe prophase.

Chromosomes become visible, each replicated chromosome is made of two identical chromatids, spindle fibers begin to form and the nuclear membrane begins to disintegrate. Signup and view all the answers

Describe metaphase.

Chromosomes line up in the middle of the cell, spindle fibers attach to the replicated chromosomes at their centers. Signup and view all the answers

Describe anaphase.

Spindle fibers separate sister chromatids into separate chromosomes and move them to opposite sides of the cell. Signup and view all the answers

Describe telophase.

Single chromosomes are in two "piles" that will become two nuclei. New nuclear membrane begins to form around the two piles of separated chromosomes. Signup and view all the answers

Describe cytokinesis.

Original cell pinches in two and makes two new cells. Signup and view all the answers

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

The cell would be multinucleated. Signup and view all the answers

Why is mitosis important in a skinned knee and during the growth of the plant?

New cells must form for a skinned knee/to regrow blood vessels and skin. Also to grow plants to make it bigger. Signup and view all the answers

What would the effect be on a cell if the sister chromatids did not line up correctly during metaphase?

If the division of cells are not accurate, cells could end up with too few or too many chromosomes. This could lead to the death of a cell or mutation. Signup and view all the answers

Describe the effects on mitosis in a cell that has been treated with colchicine.

The spindle fibers would not be formed correctly. Chromosomes would not be able to divide correctly. Signup and view all the answers

Predict how binary fission in prokaryotic cells might be different from mitosis in eukaryotic organisms.

Less complicated than mitosis. Single chromosome is copied and cell is pinched into two new cells, each with a single chromosome. Signup and view all the answers

Study Notes

Mitosis Overview

Mitosis consists of four main phases: Prophase, Metaphase, Anaphase, and Telophase.
It occurs during the cell cycle, specifically between G1 (growth phase) and G2 (post-DNA synthesis phase).

Cell Cycle Phases

Interphase includes three phases: G1 (growth), S (DNA synthesis), and G2 (preparation for mitosis).
One cell begins mitosis and divides into two cells by the end.

Chromosome Structure and Division

Each replicated chromosome consists of two sister chromatids.
During Prophase, four replicated chromosomes are present.
In Telophase, each new cell contains four single chromosomes.

Chromosome Importance

Chromosomes are composed of DNA and proteins, essential for carrying genetic information.

Consequences of DNA Replication Failure

Cells may have incomplete sets of chromosomes if DNA replication does not occur prior to cytokinesis, leading to non-viable cells.

Role of DNA Replication

DNA must be replicated during the S phase to ensure both new cells receive the correct number of chromosomes.

Mitosis Stages

Prophase: Chromosomes become visible; nuclear membrane disintegrates; spindle fibers form.
Metaphase: Chromosomes align at the cell's equator; spindle fibers attach at their centromeres.
Anaphase: Spindle fibers pull sister chromatids apart, moving them to opposite sides of the cell.
Telophase: Two distinct groups of single chromosomes form; nuclear membranes start to reassemble.

Cytokinesis

Cytokinesis is the division of the cytoplasm, creating two daughter cells.
It follows mitosis, ensuring nuclei are divided before the rest of the cell divides.

Chromosome Coiling Necessity

DNA must coil into chromosomes prior to division to prevent loss or damage during separation.

Mitosis vs. Cytokinesis

Mitosis is crucial for accurate nuclear content division before cytokinesis occurs.

Effects of Misalignment and Treatment

Improper alignment during Metaphase can cause aneuploidy (too many or too few chromosomes), affecting cell viability.
Colchicine disrupts spindle fiber formation, leading to incorrect chromosome separation during mitosis.

Multinucleated Cells

If mitosis occurs without cytokinesis, the resulting cell will have multiple nuclei.

Importance of Mitosis

Essential for healing (e.g., skinned knee) and plant growth, facilitating formation of new cells and tissues.

Binary Fission in Prokaryotes

Binary fission is simpler than mitosis; it involves a single chromosome being copied and the cell pinching into two new cells, each with one chromosome.

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Description

Test your knowledge on the phases of mitosis and the cell cycle with these flashcards. This quiz covers important concepts such as interphase and the specific stages of mitosis, helping you to solidify your understanding of cell division.