Presentation is loading. Please wait.

Presentation is loading. Please wait.

12/8/13 Objective: How does meiosis contribute to genetic variation? Do Now: -Take out your notes, online lab, and cancer activity from Friday.

Published byGrant Ball Modified over 8 years ago

Similar presentations

Presentation on theme: "12/8/13 Objective: How does meiosis contribute to genetic variation? Do Now: -Take out your notes, online lab, and cancer activity from Friday."— Presentation transcript:

1 12/8/13 Objective: How does meiosis contribute to genetic variation? Do Now: -Take out your notes, online lab, and cancer activity from Friday

2 Produces sex cells (egg and sperm) Produces 4 cells with HALF the normal chromosome number How many chromosomes do human body cells have? How many chromosomes do human sex cells have? (egg and sperm) How the heck does that happen?????

3 Gametes= sex cells that have HALF the normal number of chromosomes (human= 23) Somatic Cells= body cells that have full set of chromosomes (human = 46)

4 -Haploid (n): a cell with half the normal number of chromosomes (gametes) -Diploid (2n): a cell with full set of chromosomes (somatic cell)

5

6 Karyotype Sex Chromosomes: 23 rd Pair: XX = female XY= male

7

8 Homologous Chromosomes Same chromosome, one is from mom, one is from dad

9 Downs Syndrome

10 Turners Syndrome

11 Prophase I: - Spindle forms, chromosomes condense nuclear membrane disappears -Homologous chromosomes stick together forming 4 chromatids (tetrads)

12 Genetic Variation Crossing Over: occurs during Prophase I where homologous chromosomes exchange pieces.

13 Metaphase I: Tetrads (Homologous chromosomes) line up at the middle

14 Anaphase I: Homologous chromosomes separate and move to poles

15 Telophase I: 2 daughter cells are formed (chromosomes are still duplicated)

16 Prophase II: Spindle forms in daughter cells, nuclear membrane breakdown

17 Metaphase 2: Sister chromatids line up in the middle of cell

18 Anaphase II: Sister chromatids separate and move to poles

19 Telophase II: Cells split producing 4 haploid daughter cells that are ALL GENETICALLY DIFFERENT!

20 Genetic Variation Crossing Over: occurs during Prophase I where homologous chromosomes exchange pieces.

21 Meiosis Sour Straws 1. Maternal and Paternal Homologous Chromosomes

22 Meiosis Sour Straws

23 2. Crossing Over – Chromosomes exchange sections of DNA

24 Meiosis Sour Straws 2. Crossing Over – Chromosomes exchange sections of DNA

25 Meiosis Sour Straws 3. Meiosis I: Homologous Chromosomes separate

26 Meiosis Sour Straws 4. Sister chromatids separate to form four unique gametes

27 Meiosis Sour Straws

Download ppt "12/8/13 Objective: How does meiosis contribute to genetic variation? Do Now: -Take out your notes, online lab, and cancer activity from Friday."

Similar presentations

Chromosomes and Cell Division. Chromosomes Your somatic cells (all excluding egg and sperm cells) contain 46 chromosomes Chromosomes contain the genetic.

Chromosomes and Cell Division. Chromosomes Your somatic cells (all excluding egg and sperm cells) contain 46 chromosomes Chromosomes contain the genetic.
Meiosis Chapter 11.4.

Meiosis Chapter 11.4.
11-4 Meiosis Pg. 275.

11-4 Meiosis Pg. 275.
Meiosis Honors Biology Spring 2013.

Meiosis Honors Biology Spring 2013.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49.

Do Now!! o Now What is the purpose of Mitosis?

Do Now!! o Now What is the purpose of Mitosis?
Chapter 10 Meiosis Textbook pages 270 - 276.

Chapter 10 Meiosis Textbook pages
Meiosis Section10.2. In the body cells of animals and most plants, chromosomes occur in pairs. Diploid and haploid cells A cell with two of each kind.

Meiosis Section10.2. In the body cells of animals and most plants, chromosomes occur in pairs. Diploid and haploid cells A cell with two of each kind.
Meiosis.

Meiosis.
What occurs during the phases of meiosis?

What occurs during the phases of meiosis?
Meiosis Forming haploid cells for sexual reproduction.

Meiosis Forming haploid cells for sexual reproduction.
Cell Division Meiosis Relationship Between Meiosis and Genetics Meiosis results in egg (females) and sperm (males) cells. When egg and sperm combine.

Cell Division Meiosis Relationship Between Meiosis and Genetics Meiosis results in egg (females) and sperm (males) cells. When egg and sperm combine.
Meiosis Cell division process whereby the number of chromosomes in a diploid cell is reduced by half through the separation of homologous chromosomes.

Meiosis Cell division process whereby the number of chromosomes in a diploid cell is reduced by half through the separation of homologous chromosomes.
Lesson 9.3: Meiosis: The Life Cycle of Sex Cells Goals: Identify male and female gametes Compare chromosome numbers between somatic cells and gametes.

Lesson 9.3: Meiosis: The Life Cycle of Sex Cells Goals: Identify male and female gametes Compare chromosome numbers between somatic cells and gametes.
Meiosis Division of Sex Cells. Meiosis  A process of reduction division in which the number of chromosomes per cell is cut in half through the separation.

Meiosis Division of Sex Cells. Meiosis  A process of reduction division in which the number of chromosomes per cell is cut in half through the separation.
Topic 4.2 Meiosis. Topic 4.2.1 Meiosis is a Reduction Division Diploid nucleus divides to form haploid nuclei Form of cell division which results in gametes.

Topic 4.2 Meiosis. Topic Meiosis is a Reduction Division Diploid nucleus divides to form haploid nuclei Form of cell division which results in gametes.
 A form of nuclear cell division that creates 4 haploid cells from one diploid cell. This process occurs in the gametes (sex cells)  Involves 2 rounds.

 A form of nuclear cell division that creates 4 haploid cells from one diploid cell. This process occurs in the gametes (sex cells)  Involves 2 rounds.
Meiosis Chapter 11.4 Objectives Describe how homologous chromosomes are alike and how they differ Contrast haploid and diploid cells Summarize the process.

Meiosis Chapter 11.4 Objectives Describe how homologous chromosomes are alike and how they differ Contrast haploid and diploid cells Summarize the process.
 Gametes – sex cells  Gametes fuse  fertilization  zygote  Gametes are formed by meiosis  Somatic cells – all other cells but sexual cells  Every.

 Gametes – sex cells  Gametes fuse  fertilization  zygote  Gametes are formed by meiosis  Somatic cells – all other cells but sexual cells  Every.
11-4 Meiosis I. Chromosome Number A. Homologous- corresponding chromosomes, one from the male and one from the female. B. Diploid - A cell that contains.

11-4 Meiosis I. Chromosome Number A. Homologous- corresponding chromosomes, one from the male and one from the female. B. Diploid - A cell that contains.

Similar presentations

Ads by Google