Mitosis & Meiosis Review

Mitosis & Meiosis Review

​Vocabulary:

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Mitosis: Cell division that creates two diploid somatic cells​.

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Somatic cells: normal body cells (skin, liver, muscle, etc.)

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Diploid: the normal number of chromosomes. Also written as "2n".​

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​Vocabulary:

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Meiosis: Cell division that creates four haploid gametes​.

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Gametes: sex cells (sperm or ovum, which means egg)

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Haploid: half, or half the normal number of chromosomes. Also written as "n".​

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​Each of your somatic cells has a full copy of your DNA.

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​​Before a cell divides, this DNA is arranged into chromosomes.​

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​Human somatic cells have 46 chromosomes. 46 is the diploid, or 2n, number in humans.

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Human gametes have 23 chromosomes. 23 is the haploid, or n, number in humans.

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Other species have different numbers of chromosomes.

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For example, the diploid (2n) number in dogs is ​78.

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The word haploid means half, so the haploid number will always be half of the diploid number.​

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Multiple Choice

Somatic cells are:

• Normal body cells (skin, liver, muscle, etc.)

• Sex cells

• Gametes

• Sperm and ovum (egg)

Multiple Select

Gametes are (choose three correct answers):

• Normal body cells (skin, liver, muscle, etc.)

• Sex cells

• Sperm

• Ovum (egg)

• Somatic cells

Multiple Choice

Mitosis is cell division that creates:

• Two diploid somatic cells

• Four diploid gametes

• Two haploid somatic cells

• Four haploid gametes

Multiple Choice

Meiosis is cell division that creates:

• Two diploid somatic cells

• Four diploid gametes

• Two haploid somatic cells

• Four haploid gametes

Multiple Select

Diploid means (choose two correct answers):

• Having the normal number of chromosomes

• Having half the normal number of chromosomes

• 2n

• n

Multiple Select

Haploid means (choose two correct answers):

• Having the normal number of chromosomes

• Having half the normal number of chromosomes

• 2n

• n

Multiple Choice

True or false: all living things have the same number of chromosomes.

• True

• False

Multiple Choice

The diploid number of chromosomes in humans is 46.

What is the haploid number of chromosomes in humans?

• 92

• 46

• 23

• 12

Multiple Choice

The diploid number of chromosomes in dogs is 78.

What is the haploid number of chromosomes in dogs?

• 156

• 78

• 39

• 12

Multiple Choice

The haploid number of chromosomes in cats is 19.

What is the diploid number of chromosomes in cats?

• 76

• 38

• 19

• 12

​Cell Cycle: G1 -> S -> G2 -> M​

All cells go through the cell cycle, starting with G1 and ending with M.

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G1, S, and G2 are all part of a large phase called Interphase.​

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​Cell Cycle: G1 -> S -> G2 -> M​

​During the S phase of Interphase, the cell makes a copy of all its chromosomes.

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So for a brief moment, the cell has 92 chromosomes instead of 46.​

​Cell Cycle: G1 -> S -> G2 -> M​

M phase is broken down into 5 smaller phases:

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Prophase

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Metaphase

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Anaphase

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Telophase

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Cytokinesis​

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​Cell Cycle: G1 -> S -> G2 -> M​

In prophase, the DNA condenses to chromosomes and the nucleus breaks apart.

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​Cell Cycle: G1 -> S -> G2 -> M​

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Metaphase is middle phase. In metaphase, the chromosomes go to the middle of the cell.

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​Cell Cycle: G1 -> S -> G2 -> M​

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In anaphase, the spindle fibers pull the chromosomes to opposite sides of the cell.

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​Cell Cycle: G1 -> S -> G2 -> M​

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In telophase, the cell begins to split apart, and a new nucleus forms in each new cell.

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​Cell Cycle: G1 -> S -> G2 -> M​

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In cytokinesis, the cell finishes splitting apart, and you end up with two cells.

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​Cell Cycle: G1 -> S -> G2 -> M​

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Meiosis is similar to mitosis, but all the steps happen twice.

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So we say there is Meiosis I, and Meiosis II.​

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​Cell Cycle: G1 -> S -> G2 -> M​

Meiosis I consists of:

Prophase I

Metaphase I

Anaphase I

Telophase I

Cytokinesis I

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Meiosis II consists of:​

​Prophase II

Metaphase II

Anaphase II

Telophase II

Cytokinesis II

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Crossing over occurs during Prophase I of Meiosis I.

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During crossing over, homologous chromosomes contact each other and exchange DNA.​

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This increases genetic diversity and makes sure each gamete is different.​

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Crossing over

Multiple Choice

Which of the followings gives the steps of the cell cycle in order?

• Interphase, prophase, metapahse, anaphase, telophase, cytokinesis.

• Cytokinesis,

  prophase, metapahse, anaphase, telophase,

  interphase.

• Metaphase, telophase, anaphase, cytokinesis, interphase, prophase.

• G2,

  interphase,

  G1,

  interphase,

  S,

  interphase.

Multiple Choice

What is the middle phase of mitosis, when the chromosomes line up in the middle of the cell?

• Anaphase

• Telophase

• Prophase

• Metaphase

Multiple Choice

What is the first phase of mitosis, when the DNA condenses to chromosomes and the nucleus disappears?

• Anaphase

• Telophase

• Prophase

• Metaphase

Multiple Choice

What is the phase of mitosis where the spindle fibers pull the chromosomes apart to opposite sides of the cell?

• Anaphase

• Telophase

• Prophase

• Metaphase

Multiple Choice

What is the phase of mitosis where the cell starts to split in two?

• Anaphase

• Telophase

• Prophase

• Metaphase

Multiple Choice

During which part of the cell cycle does the cell make a copy of its chromosomes?

• Prophase

• S Phase

• Mitosis

• Telophase

​Mitosis:

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The phases of the cell cycle happen once.

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Interphase

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Prophase

Metaphase

Anaphase

Telophase

Cytokinesis​

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​Meiosis:

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Follows the same steps as mitosis, but cell division happens twice.

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Interphase

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Prophase x2

Metaphase x2

Anaphase x2

Telophase x2

Cytokinesis​ x2

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​Mitosis:

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Cell division that creates two diploid somatic cells​.

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Mitosis is used to repair or replace old or damaged cells, or for the growth and development of an organism.​

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​Meiosis:

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Cell division that creates four haploid gametes​.

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Meiosis is for the creation of offspring.

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​Mitosis:

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The diploid somatic cells created by mitosis are all the normal cells of the body:

skin cells, muscle cells, intestinal cells, liver cells, etc.​

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Somatic is just the fancy scientific term for "body".​

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​Meiosis:

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The haploid gametes created by meiosis are the sex cells:

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sperm in males, ovum (egg) in females.​

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Gamete is just the fancy scientific term for "sex cell".​

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​Mitosis:

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The two diploid (2n) somatic cells created by mitosis are genetically identical.

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In other words, the two cells are twins, with the exact same DNA.​

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​Meiosis:

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The four haploid (n) gametes created by meiosis are genetically different.

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This is why children born to the same parents can have such different looks, interests, and personalities.

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Multiple Choice

What type of cell division is shown in the image?

• Mitosis

• Meiosis

Multiple Choice

What type of cells will be created by this cell division?

• Two diploid somatic cells

• Four diploid gametes

• Two haploid somatic cells

• Four haploid gametes

Multiple Choice

How many chromosomes will each of the daughter cells have?

• 92

• 46

• 23

• 12

Multiple Choice

What type of cell division is shown in the image?

• Mitosis

• Meiosis

Multiple Choice

What type of cells will be created by this cell division?

• Two diploid somatic cells

• Four diploid gametes

• Two haploid somatic cells

• Four haploid gametes

Multiple Choice

How many chromosomes will each of the daughter cells have?

• 92

• 46

• 23

• 12

Multiple Choice

The image shows "crossing over" occurring.

What is the effect of "crossing over".

• Increases genetic diversity

• Decreases genetic diversity

• Increases reproduction rate

• Kills the organism

Multiple Choice

The image shows "crossing over".

When does "crossing over" occur?

• Prophase II of Meiosis

• Prophase of Mitosis

• Anaphase I of Meiosis

• Prophase I of Meiosis