Cell Division: Mitosis and DNA Duplication

Questions and Answers

Why do your cells divide?

Your body makes new cells to reproduce, and to grow and replace cells that have died.

What is mitosis?

Asexual cell reproduction.

What does the Greek word for threads refer to in cell division?

Mitosis.

What are the main points of mitosis?

It produces two exact copies Signup and view all the answers

What happens to the DNA during cellular division?

DNA must duplicate before a cell divides. Signup and view all the answers

During most of a cell's life cycle, DNA is wrapped around proteins to form what?

Chromatin. Signup and view all the answers

What is the structure of DNA in prokaryotic cells?

Have no nucleus and a single, circular DNA molecule. Signup and view all the answers

What is binary fission?

Cell division in bacteria where the bacterium splits into two parts. Signup and view all the answers

How complex is DNA in eukaryotic cells compared to prokaryotic cells?

More complex and contains more DNA. Signup and view all the answers

What are chromosomes?

The visible duplicated DNA found in the nucleus of eukaryotic cells. Signup and view all the answers

What holds together chromatids?

Centromere. Signup and view all the answers

What is the total length of DNA present in one human?

2.0 × 10^13 meters. Signup and view all the answers

What is the rate of mitosis in most animals?

25 million cells/second. Signup and view all the answers

What are the three stages of the cell cycle?

Interphase, Mitosis, Cytokinesis. Signup and view all the answers

What happens during interphase?

Cell grows and copies its organelles and chromosomes. Signup and view all the answers

What happens during mitosis?

Chromatid separation occurs. Signup and view all the answers

What is cytokinesis?

Cell division. Signup and view all the answers

Where does cytoplasm division begin in eukaryotic cells without a cell wall?

At the cell membrane. Signup and view all the answers

In which organisms does a cell plate form during division?

In plants, algae, and fungi. Signup and view all the answers

What are the four phases of mitosis?

Prophase, Metaphase, Anaphase, Telophase. Signup and view all the answers

What happens during prophase?

Nuclear membrane dissolves and chromosomes condense. Signup and view all the answers

What happens during metaphase?

Chromosomes line up along the equator of the cell. Signup and view all the answers

What happens during anaphase?

Chromatids separate and move to opposite sides of the cell. Signup and view all the answers

What occurs during telophase?

Nuclear membrane forms around each set of chromosomes. Signup and view all the answers

Study Notes

Cell Division Overview

Cells divide for reproduction, growth, and replacement of dead cells.
Mitosis is a type of asexual reproduction requiring only one parent cell.

Mitosis Defined

Mitosis involves the copying of cell structures, leading to two identical daughter cells.
Most human cells, such as skin cells, and many single-celled organisms reproduce via mitosis.

DNA Duplication

DNA must duplicate prior to division in both prokaryotic and eukaryotic cells.
In non-dividing cells, DNA exists as chromatin, a complex of DNA and proteins.

DNA in Prokaryotic Cells

Prokaryotes lack a nucleus and have a single, circular DNA molecule.
Binary fission is the method of division in bacteria, splitting the bacterium into two, each with an identical DNA copy.

DNA in Eukaryotic Cells

Eukaryotic DNA is more complex and packaged into chromosomes during division.
Chromosomes consist of duplicated DNA and are made of chromatids joined by a centromere.

Chromatin and Chromosomes

Chromatin condenses to form chromosomes during cell division, making DNA visible.
Each duplicated chromosome contains two identical chromatids.

Interesting DNA Fact

The total length of DNA in a single human is about 2.0 × 10^13 meters, equivalent to approximately 70 trips from Earth to the sun.
Humans have 46 chromosomes, while fruit flies have 8 and potatoes have 48.

Cell Cycle Stages

The cell cycle includes Interphase, Mitosis, and Cytokinesis.
Interphase is when the cell grows and replicates its organelles and chromosomes.

Interphase

Cells grow and copy their organelles and chromosomes; chromatids form as a result.

Mitosis

Mitosis involves four stages: Prophase, Metaphase, Anaphase, and Telophase.
It ensures each daughter cell receives an exact copy of chromosomes.

Cytokinesis

Cytokinesis is the final stage when the cell divides into two identical cells.
In the absence of a cell wall, the cleavage furrow forms in animal cells. In plant cells, a cell plate forms.

Stages of Mitosis

Prophase: Nuclear membrane dissolves, and chromosomes condense into visible structures.
Metaphase: Chromosomes align along the cell's equator and pair with homologous chromosomes.
Anaphase: Sister chromatids separate and move toward opposite cell poles.
Telophase: Mitosis concludes; nuclear membranes reform around each chromosome set, and they unwind.

Mitosis Rate

The average rate of mitosis in most animals is approximately 25 million cells per second.

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Description

This quiz covers the fundamentals of cell division, focusing on mitosis and DNA replication. Understand the processes involved in both prokaryotic and eukaryotic cells, and how these processes contribute to growth and reproduction. Test your knowledge on the differences between cell structures and the roles of DNA in cell division.