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EOC Thursday
April 18
Mitosis
PRE- QUIZ jot down your answers…we will go over these again at the end.
Key questions and ideas
1. What are two purposes of mitosis?
2. Why does the DNA need to replicate before mitosis can occur?
3. If a parent cell has 8 chromosomes (8 pairs) how many
chromosomes will each daughter cell have after mitosis?
4. In multicellular organisms, which cells are haploid?
5. Typical animal cells are diploid. Where did each pair of
chromosome come from?
6. True or false? Assexual reproduction produces unique individuals.
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Cells have distinct phases of growth, reproduction, and
normal functions
What does it mean when we say cells reproduce?
WHY do cells need to reproduce?
 The cell cycle
The cell cycle is a regular pattern of growth, DNA replication, and cell
division.
 Interphase
 Mitosis
 Cytokinesis
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Interphase
Growth and daily functions occur. Described in steps:
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Gap 1 (G1): cell growth and normal functions
DNA synthesis (S): copies DNA
Gap 2 (G2): additional growth
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Mitosis
Cells divide making two ________copies
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Vocabulary Review
DNA
Genetic information that “codes” for what organisms look like and directs cell activities
Chromosome
DNA is made up of chromosomes. These contain genes or individual directions for characteristics like hair
color, eye color etc. Each living thing has a different number of chromosomes. Humans have 46 (23 pairs),
Fruit flies have 8 (4 pairs), Pineapple have 50 (25 pairs). Check out this chart
http://en.wikipedia.org/wiki/List_of_organisms_by_chromosome_count
Chromatids
One half of the duplicated chromosomes. Usually referred to as “sister chromatids”
Haploid
This means the cells has HALF a set of chromosomes. This is important when we study meiosis or sexual
reproduction. Sperm and egg are haploid cells.
Diploid
Means TWO of each chromosome. All your body cells, excludes sex cells (sperm and egg) contain TWO of
each chromosome (pair), one came from your mom, one came from your dad.
Replication
Make an exact copy. DNA does this BEFORE mitosis.
Parent cell
Refers to the original cell that we are talking about before it divides
Daughter cell
Refers to the resulting cells after the parent cells divides
Mitosis divides the cell in four phases
 Prophase, Metaphase, Anaphase and Telophase
 Prophase
 During prophase, ____________condense and spindle fibers form.
 The spindle fibers will help pull the two sets of chromosomes apart.
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Remember, in interphase the chromosomes doubled, or replicated so we have a double set of DNA
before we get to this step.
Metaphase
 During metaphase, chromosomes line up in the _______ of the cell.
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A good way to remember this one is metaphase and middle both begin with M
Anaphase
During anaphase, sister chromatids ________ to opposite sides of
the cell
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The DNA is moving apart...apart and anaphase both begin with the letter A
Telophase
 During telophase, the new ________ form and chromosomes begin to uncoil.
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Starting to look like two cells...telophase and two begin with the letter T
Cytokinesis
Separation of the cytoplasm forming two distinct cells. Not always
distinguished from telophase.
Animation of Mitosis
http://cellsalive.com/mitosis.htm
 Be able to identify the steps from images and descriptions
 Prophase
 Metaphase
 Anaphase
 Telophase
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new nuclei form and chromosomes begin to uncoil.
chromosomes line up in the middle of the cell.
sister chromatids separate to opposite sides of the cell
chromosomes condense and spindle fibers form.
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Cells divide at ______ rates.
 the rate of cell division varies with the need for those types of
cells.
Cells division is regulated/controlled
Internal and external factors regulate cell division.
 External factors include physical and chemical signals.
 Growth factors are proteins that stimulate cell division.
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Most mammal cells form a single layer in a culture dish and stop dividing once they touch
other cells.
Uncontrolled cell division
 Cell division is uncontrolled in cancer.
 Cancer cells form disorganized clumps called tumors.
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Benign tumors remain clustered and can be removed.
Malignant tumors metastasize, or break away, and can form more tumors
Mitosis and asexual reproduction
 Asexual reproduction is the creation of offspring from a ______
parent.
 In SINGLE celled organisms sexual reproduction is not
possible…there are not boys and girls. 
 Protists and algae are eukaryotic examples
 Organisms must be able to reproduce….
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 Mitosis is the mechanism for making MORE single celled individuals
All the individuals are genetically ________
Binary fission
 Binary fission is similar in function to mitosis
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Binary fission produces two daughter cells genetically identical to the parent cell.
Binary fission occurs in
prokaryotes. What are prokaryotes?
Some eukaryotes reproduce through mitosis.
 Budding forms a new organism from a small projection growing
on the surface of the parent.
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The small projection then grows by adding more cells through
the process of mitosis. The new individual is genetically identical
to the orginal.
What to turn in this week?
Copy and paste your answers to the key questions into the text box.
If you did not attend live you will need to watch the recording for
the answers!