Mitosis

Separating the components of the cell into two parts

The incredible cell

The center of our Study: The NucleusNuceleolus: Center of the nucleus

Chromatin- is a mass of genetic material composed of DNA

Chromosomes• Chromo-colored• -Somes-bodies

• Threadlike structure within the nucleus containing genetic information

Passed from one generation of cells to the next

Genetic Information: DNA•DNA is a molecule that stores information and acts as a blueprint for the body of an organism

•provides the instructions for all the information a living organism needs to grow and function

• DNA is the molecule: Deoxyribonucleic acid

DNA forms a chromosome

1- Molecule forms by amino acid base pairs chemically bonding to form DNA.

2- DNA twists and curls

3- Twists and curls until it forms a chromosome.

Chromosome number

Diploid• body cells• Produced through mitosis• (2n)= 46 chromosomes• 23 from male and 23 from

female

Haploid

• (n)= total of 23 • sperm and egg cell

-produced by meiosis

Diploid vs. Haploid

ChromosomesOne copy from male (dad)

One Copy from female (mom)

How is genetic information passed from one generation of cells to the next?

If a cell divides how is genetic information transferred?

“sister chromatids”-

Chromatids

• Each chromosome has two identical arms-sister chromatids

• When the cell divides:

– The “sister” chromatids separate and one goes to each of the two new cells

Cell CycleSeries of events that cells go through as they grow and divide

During the cell cycle:1) A cell grows2) Prepares for

division3) Divides to form two

daughter cells4) Cycle begins again

Interphase

• Interphase has three steps – G1– S– G2

• G1 phase- Growth phase– Definition: cell grows, carries out normal functions

and duplicates cellular organelles

• S phase– Definition: Synthesis phase where DNA

replicates/duplicates

• G2 Phase– Definition: Cell prepares for mitosis

Mitosis

• Mitosis has 4 steps– Prophase– Metaphase– Anaphase– Telophase

– Mitosis

Prophase

• DNA in the nucleus of a cell condenses and becomes visible under the microscope– Chromosomes condense– Membrane surrounding the nucleus disappears

Metaphase

• Metaphase – Chromosomes line up in the middle of the cell

Anaphase

• Anaphase:– Chromosomes split apart • Creates two separate identical chromosomes

– Chromosomes are pulled to opposite sides of the cell

Telophase

• Telophase:– A new nuclear membrane forms around each

group of chromosomes

Cytokinesis

• Cytokinesis is the last step in the cell cycle– The cytoplasm divides to create two identical

daughter cells– Daughter cells then begin interphase

Uncontrolled cell growth

• When a cell divides excessively and invade other organs it is known as cancer.

• Cancer cells do not respond normally to the bodies control mechanism to stop cell growth.

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Metaphase

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Anaphase

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prophase

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metaphase

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Prophase

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Telophase

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Anaphase

Let’s Practice

• Cell cycle and Mitosis Review• Mitosis Animation

LET’S ACT IT OUT

• Directions: 1) Clear desk to the perimeter of the room to

create a wide open space in the center of the room

2) Get a pink or blue sheet of paper3) Listen to narration and act out each phase in

mitosis4) Review/Questions