G9 Chap 9.2 Mitosis and Cytokinesis

Mitosis and Cytokinesis

By Karen Lolli Chapter 9 Section 2

Multiple Choice

During mitosis, which part of the cell divides?

• organelles

• nucleus

• cytoplasm

Mitosis

Stage of cell cycle in which the copies of DNA​ separate, creating 2 nuclei​ (plural for nucleus)

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In multicellular organisms this​ makes new cells

• organisms grow bigger in size

• replaces damaged cells​

Remember....

During Interphase (S stage) DNA was copied

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Humans have 46 chromosomes = 46 pieces of DNA

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Each chromosome is copied, and the copies are attached to each other​

Multiple Choice

During which stage of Interphase are the chromosomes copied?

• G1

• S

• G2

Multiple Choice

How many chromosomes do humans have?

• 26

• 36

• 46

• 56

Chromosomes

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Chromatid (I) = one condensed piece of DNA

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2 identical chromatids (I) are attached at the centromere​​, forming X shape chromosome

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Centromer​e = central location where 2 chromatids are attached together

Stages of Mitosis

Prophase (P = prepare)

• Nucleus disappears

• Spindle apparatus forms on either side of the cell

  • Fibers come out of the centrioles, they will pull the chromosomes apart

• Chromosomes (X) are not organized yet

Multiple Choice

What disappears during Prophase?

• DNA

• nucleus

• cyotplasm

• spindle fibers

Multiple Choice

What forms during Prophase?

• nucleus

• DNA

• cyotplasm

• spindle apparatus

Stages of Mitosis

Metaphase (M = Middle​)

• Spindle apparatus pushes the chromosomes (X) to the middle of the cell​ in a line

Multiple Choice

How are chromosomes arranged during Metaphase?

• in a line in the middle of the cell

• in a line on one side of the cell

• they're not arranged

Stages of Mitosis

Anaphase (A = Away)

• Chromosomes (X) are broken apart at the centromere

  • Spindle apparatus pulls the chromatids (I) away from each other, to the opposite sides of the cell

Multiple Choice

Where are the chromosome (X) broken apart during Anaphase?

• spindle fiber

• centromere

• chromatids

Multiple Choice

Where are the chromatids pulled to during Anaphase?

• to the middle of the cell

• to opposite sides of the cell

Stages of Mitosis

Telophase (T = Two)

• ​Two nuclei form around the 2 sets of DNA

• Spindle apparatus disappears

• Still only 1 cell!​

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Multiple Choice

How many nuclei are in the cell after Telophase?

• 1

• 2

• 3

• 4

Multiple Choice

How many cells are there at the end Telophase?

• 1

• 2

• 3

• 4

Cytokinesis

Cytoplasm (and other cellular contents) divides, creating 2 separate cells

• They are each called Daughter Cells

• Both cells are identical​

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Multiple Choice

What divides during cytokinesis?

• nucleus

• DNA

• spindle fibers

• cytoplasm

Multiple Choice

How many cells are there after Cytokinesis?

• 1

• 2

• 3

• 4