HW: IP: Mitosis & Meiosis *Signed Progress Report and Quiz: Friday!* Tuesday March 14, 2017 I can: differentiate between mitosis and meiosis explain how meiosis leads to diversity Agenda (10) Catalyst (25) GN: Meiosis (15) GP: Venn Diagram (15) Kahoot! (15) IP: Meiosis (5) Exit Ticket Catalyst Write down your favorite color, food, or animal. Complete the catalyst matching sheet and turn in! HW: IP: Mitosis & Meiosis *Signed Progress Report and Quiz: Friday!*

HW: Mitosis and Meiosis Tic Tac Toe Options Wednesday March 15, 2017 I can: practice and understand the steps of mitosis and meiosis Agenda (10) Catalyst (10) Video Review (65) Group Work Catalyst 1. What is one difference between mitosis and meiosis? 2. How many cells are made after one round of meiosis? Are they identical or unique? 3. How many cells are made after one round of mitosis? Are they identical or unique? HW: Mitosis and Meiosis Tic Tac Toe Options

Exit Ticket Review 1. How many cells are produced at the end of meiosis? _____ 2. How many times do cells split in meiosis? _______ 3. What types of cell does meiosis produce? ___________________________ (gametes or somatic) 4. How do the number of chromosomes in the daughter cells compare to the original cells? __________________________ 4 2 gametes Has HALF the number

Exit Ticket Review 5. Which describes why meiosis promotes genetic variability? A. Meiosis produces four gametes that have half the number of chromosomes of the parent cell. B. Meiosis produces four gametes that have twice the number of chromosomes of the parent cell. C. Meiosis produces four gametes that have the same number of chromosomes as the parent cell. D. Meiosis produces four gametes that have four times the number of chromosomes of the parent cell.

Exit Ticket Review 6. What is a result of crossing over during meiosis? A. genetic variation B. extra chromosome formed C. loss of chromosomes D. production of gametes

Exit Ticket Review 1. As a corn plant ages, its leaves grow. Which process is directly responsible for the growth of these leaves? A. the division of cells in the plant B. the release of oxygen from the plant C. the absorption of carbon dioxide in the stem D. the transportation of nutrients from the rooms

Exit Ticket Review At the end of mitosis, how many daughter cells are produced? What is one purpose of mitosis? What happens during each stage of the cell cycle? G1 (growth 1) – S (synthesis) – G2 (growth 2) – 2 Growth & repair Cells grow, make new organelles and proteins DNA replication Cell prepares for mitosis

Asexual Reproduction

Big Picture: What accounts for genetic variation in organisms?

Why do siblings look different from each other?

Why do siblings look different from each other?

Why do children look different form their parents?

Why do children look different form their parents?

Why do children look different form their parents?

genetic variation! intercourse Sexual reproduction involves the contribution of genetic material from two parents, and results in…. genetic variation! intercourse

Turn and Talk Why is sexual reproduction (and diversity) a good thing?

Human Chromosome Number Human body cells contain 2 copies of each of 23 chromosomes. 1 copy comes from each parent 2 copies = diploid (2n) copy from dad copy from mom Each set of chromosomes is homologous – they are the same size and contain the same information chromosome 19

Human Chromosome Number Human body cells contain 2 copies of each of 23 chromosomes. 1 copy comes from each parent 2 copies = diploid (2n) copy from mom copy from dad Each set of chromosomes is homologous – they are the same size and contain the same information After doubling during the S phase, the homologous chromosomes now form tetrads. chromosome 19

Human Cell Type Somatic Cells Gametes body cells diploid (2n) = 2 copies of 23 chromosomes made by mitosis egg and sperm haploid (1n) = 1 copy of 23 chromosomes made by meiosis

gametes Write On Your Board What type of cell are egg and sperm? (gamete or somatic) gametes

somatic cells Write On Your Board What type of cell is a skin cell? (gamete or somatic) somatic cells

haploid, 23 Write on Your Board What type of cell is a gamete (diploid or haploid), and how many chromosomes does it contain? haploid, 23

diploid, 46 Write on Your Board What type of cell is a somatic cell (diploid or haploid), and how many chromosomes does it contain? diploid, 46

somatic cells Write on Your Board What kind of cell is made by mitosis? somatic cells

Write on Your Board What kind of cell is made by meiosis? gametes

Just like mitosis, except… Meiosis (aka reduction division) is the process in which gametes are made. Just like mitosis, except… each cell divides two times each cell produces 4 daughter cells cells produced are haploid, not diploid each cell produced is different from the parent

There are many ways in which meiosis results in genetic variation, or different combinations of DNA. 1. Crossing-over During prophase I of meiosis, homologous chromosomes pair up to form a tetrad. Chromatids then cross over each other, and the crossed sections are exchanged. This results in new combinations of genes (DNA).

2. Random (or Independent) Assortment There are many ways in which meiosis results in genetic variation, or different combinations of DNA. 2. Random (or Independent) Assortment Chromosomes are separated into gametes randomly. That is why you inherit traits by chance, and you get a mix of traits from each parent.

There are many ways in which meiosis results in genetic variation, or different combinations of DNA. 3. Mutation Sometimes there is a mistake in the DNA that is not caught.

There are many ways in which meiosis results in genetic variation, or different combinations of DNA. 23 46 23 4. Sexual Reproduction Reproduction that requires 2 parents results in variation because any combination of egg and sperm is possible. Fertilization (when an egg and sperm combine) restores the correct chromosome number.

There are many ways in which meiosis results in genetic variation, or different combinations of DNA. 5. Nondisjunction Nondisjunction is when chromosomes don’t separate correctly in meiosis. It leads to the wrong number of chromosomes. It results in genetic disorders like Down Syndrome.

The genetic variation produced by meiosis ensures that there is a wide variety of traits in offspring.

Mitosis Meiosis

Write on Your Board Mitosis or meiosis: produces 2 cells mitosis

mitosis Write on Your Board Mitosis or meiosis: produces cells that are identical to the parent mitosis

meiosis Write on Your Board Mitosis or meiosis: produces cells that are genetically different from the parent meiosis

Write on Your Board Mitosis or meiosis: produces 4 cells meiosis

mitosis Write on Your Board chromosome # is the same as parent Mitosis or meiosis: chromosome # is the same as parent mitosis

meiosis Write on Your Board Mitosis or meiosis: has half as many chromosomes as parent cell meiosis

meiosis Write on Your Board increases genetic diversity Mitosis or meiosis: increases genetic diversity meiosis

meiosis Write on Your Board chromosome number is divided in half Mitosis or meiosis: chromosome number is divided in half meiosis

Write on Your Board Mitosis or meiosis: results in clones mitosis

Write on Your Board Mitosis or meiosis: crossing-over occurs meiosis

Write on Your Board Mitosis or meiosis: asexual reproduction mitosis

Write on Your Board Mitosis or meiosis: makes gametes meiosis

meiosis Write on Your Board part of sexual reproduction Mitosis or meiosis: part of sexual reproduction meiosis

Write on Your Board Mitosis or meiosis: makes somatic cells mitosis

meiosis Write on Your Board Mitosis or meiosis: occurs in reproductive organs (ovaries, testes) meiosis

mitosis Write on Your Board occurs in somatic cells Mitosis or meiosis: occurs in somatic cells mitosis

different combinations of DNA (genes) Write on Your Board What does crossing-over result in? different combinations of DNA (genes)