Ch 10 cell growth and division ch 11 meiosis sec 11 4
This presentation is the property of its rightful owner.
Sponsored Links
1 / 44

Ch. 10, Cell Growth and Division Ch. 11, Meiosis (sec. 11-4) PowerPoint PPT Presentation


  • 131 Views
  • Uploaded on
  • Presentation posted in: General

Ch. 10, Cell Growth and Division Ch. 11, Meiosis (sec. 11-4). Ch. 10: Cell Growth- why do cells divide instead of continue to grow? Cell Division – Cell Cycle and when a cell divides, Mitosis Regulation of the Cell Cycle- how it’s controlled, what happens when it’s out of control Ch. 11:

Download Presentation

Ch. 10, Cell Growth and Division Ch. 11, Meiosis (sec. 11-4)

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Ch 10 cell growth and division ch 11 meiosis sec 11 4

Ch. 10, Cell Growth and DivisionCh. 11, Meiosis(sec. 11-4)

  • Ch. 10:

    • Cell Growth- why do cells divide instead of continue to grow?

    • Cell Division – Cell Cycle and when a cell divides, Mitosis

    • Regulation of the Cell Cycle- how it’s controlled, what happens when it’s out of control

  • Ch. 11:

    • Phases of Meiosis

    • Comparing Mitosis and Meiosis


Cell growth

Cell Growth

I’m out of control!

Section 10.1 – Cell Growth

Box 3

Understanding the relationship between a cell’s Surface Area and Volume is the key to understanding why cells must divide as they grow.

Too Big!

Just right

TooSmall

  • How do organisms grow? Do their cells get bigger? Or do they make more cells?

    • Answer =Make more cells!!!

  • There is a limit to how big cells can grow!

  • Getting bigger does 2 things:

  • Places more demands on DNA

  • Makes it harder to move molecules across a cell’s membrane

  • Box 1

    Box 2


    Surface area to volume ratio

    Surface Area toVolume Ratio

    Surface Area (SA): 1 x 1 x 6 = 6 cm3

    (length x width x height x # sides)

    Box 4

    6 sided cube

    1 cm

    1 cm

    1 cm

    Bigger 6 sided cube

    Box 5

    3 cm

    3 cm

    Volume increases more rapidly than Surface Area and this causes the ratio of SA to V to decrease.

    3 cm

    Decreasing the SA to V ratio causes big problems for the cell. More molecules trying to go through the membrane (SA) and there’s less surface area for everything to move through!

    Box 6

    Bigger is NOT better!

    Volume (V):1 x 1 x 1 = 1 cm3

    (length x width x height)

    More surface area! Good!

    Ratio of SA to V:6/1 = 6:1

    SA:3 x 3 x 6 = 54 cm3

    Less surface area! Bad!

    V:3 x 3 x 3 = 27 cm3

    Ratio of SA to V: 54/27 = 2:1


    Ch 10 cell growth and division ch 11 meiosis sec 11 4

    Instead of growing bigger, let’s make more cells! And to do this, 1 cell will divide into 2 cells.

    Box 7

    What’s the solution to this traffic problem?


    Cell division

    Cell Division

    I’m too fat

    daughter

    daughter

    Mommy?

    • When a cell divides, the 2 cells that result are called “daughter” cells

    • Cell Division = process by which a cell divides into 2 new daughter cells

    • Before cell division, the cell replicates, or makes copies of all of its DNA

      • Solves the 2 problems with cell growth:

      • New daughter cells get one complete set of genetic information- they get their own complete genetic library

      • No more problems with SA to V ratio because daughter cells has an increased ratio of SA to V because their volume overall is reduced (one cell dividing into two makes both cells smaller)

    Box 8

    Box 9


    Cell division1

    Cell Division

    Section 10-2

    Genetic information passed from 1 generation to the next is carried by Chromosomes

    Chromosomes are made up of DNA- the part that carries the cell’s genetic information

    Box 12

    Box 13

    Mitosis is considered asexual because cells produced by it are genetically identical to the parent cell.

    Box 14

    • In Eukaryotes (you!), cell division occurs in 2 main stages:

    • Mitosis = division of the cell’s nucleus

    • Cytokinesis = division of the cytoplasm

    Box 11

    (Sy-toh-kih-NEE-sis)


    Chromosomes

    Chromosomes

    chromatid

    • When a cell isn’t in the process of dividing, chromosomes are not visible because they are spread out within the nucleus.

    • However, when cell division is beginning, the chromosomes condense into compact, visible structures we can see in a microscope.

    • Before cell division occurs, each chromosome is copied, or replicated, and the identical copies are called “sister” chromatids(KROH-muh-tids)

    replication

    Yo! Sis!

    LYLAS!

    Centromere

    Box 16

    Sister chromatid

    Sister chromatid

    Box 15


    The cell cycle

    The Cell Cycle

    Box 19

    • Cell Cycle consists of 4 phases:

    • Mitosis and Cytokinesis = M phase

    • Growth phase = G1 (“G” = gap)

    • Chromosome replication = S phase

    • Preparation for mitosis = G2

    Interphase = “in between” period of growth for a cell

    Box 18

    Box 17

    • The Cell Cycle is a series of events that cells go through as they grow and divide

      1. Cell grows

      2. Cell prepares for division

      3. Cell divides to form 2 daughter cells (each daughter cell will begin the cell cycle again)


    Cell cycle phases

    Box 21

    G1phase = when cells do most of their growing- cells increase in size and make new proteins and organelles

    Cell Cycle Phases

    Box 24

    M phase = when cell division occurs

    Box 22

    S phase = when chromosomes are replicated and synthesis of DNA molecules occurs

    G2phase = when cells make many organelles and molecules needed for cell division

    Box 23

    Box 20

    I

    G1phase

    I

    M

    M phase

    S phase

    I

    G2phase


    Mitosis

    Mitosis

    • Interphase then….

    • Mitosis has 4 phases:

    • 1. Prophase

    • 2. Metaphase

    • 3. Anaphase

    • 4. Telophase

    I then ..PMAT

    Box 25

    Interphase is NOT part of Mitosis!!!!! Remember that!


    Mitosis1

    Mitosis

    Box 26

    Interphase = cell grows and replicates its DNA and centrioles.

    Interphase

    Centrioles

    Nuclear envelope

    Chromatin


    Ch 10 cell growth and division ch 11 meiosis sec 11 4

    Interphase = cell grows and replicates its DNA and centrioles.

    Box 27

    Prophase= chromatin condenses into chromosomes, centrioles separate, spindle forms, nuclear envelope breaks down

    Interphase

    Spindle forming

    Prophase

    Centrioles

    Centromere

    Nuclear envelope

    Chromatin

    Chromosomes (paired chromatids)


    Ch 10 cell growth and division ch 11 meiosis sec 11 4

    Prophase = chromatin condenses into chromosomes, centrioles separate, spindle forms, nuclear envelope breaks down.

    Interphase= cell grows and replicates its DNA and centrioles.

    Interphase

    Spindle forming

    Prophase

    Centrioles

    Centromere

    Centriole

    Nuclear envelope

    Chromatin

    Chromosomes (paired chromatids)

    Spindle

    Centriole

    Metaphase

    Box 28

    Metaphase = chromosomes line up across the center of the cell, each chromosome is connected to a spindlefiber at its centromere


    Ch 10 cell growth and division ch 11 meiosis sec 11 4

    Prophase = chromatin condenses into chromosomes, centrioles separate, spindle forms, nuclear envelope breaks down.

    Interphase = cell grows and replicates its DNA and centrioles.

    Interphase

    Spindle forming

    Prophase

    Centrioles

    Centromere

    Centriole

    Nuclear envelope

    Chromatin

    Chromosomes (paired chromatids)

    Spindle

    Centriole

    Individual chromosomes

    Metaphase

    Box 29

    Anaphase = sister chromatids separate into individual chromosomes andmove apart

    Metaphase = chromosomes line up across the center of the cell, each chromosome is connected to a spindle fiber at its centromere

    Anaphase


    Ch 10 cell growth and division ch 11 meiosis sec 11 4

    Prophase = chromatin condenses into chromosomes, centrioles separate, spindle forms, nuclear envelope breaks down.

    Box 30

    Telophase = chromosomes gather at opposite ends of the cell and lose their distinct shapes- 2 new nuclear envelopes form

    Interphase = cell grows and replicates its DNA and centrioles.

    Interphase

    Spindle forming

    Prophase

    Centrioles

    Centromere

    Centriole

    Nuclear envelope

    Chromatin

    Chromosomes (paired chromatids)

    Spindle

    Centriole

    Telophase

    Individual chromosomes

    Metaphase

    Nuclear envelope reforming

    Anaphase = sister chromatids separate into individual chromosomes and are moved apart

    Anaphase


    Ch 10 cell growth and division ch 11 meiosis sec 11 4

    Interphase = cell grows and replicates its DNA and centrioles.

    Prophase = chromatin condenses into chromosomes, centrioles separate, spindle forms, nuclear envelope breaks down.

    Box 31

    Cytokinesis = cytoplasm pinches in ½ , each daughter cell has an identical set of chromosomes

    Interphase

    Spindle forming

    Prophase

    Centrioles

    Centromere

    Centriole

    Nuclear envelope

    Chromatin

    Chromosomes (paired chromatids)

    Spindle

    Cytokinesis

    Centriole

    Telophase

    Individual chromosomes

    Metaphase

    Nuclear envelope reforming

    Anaphase = sister chromatids separate into individual chromosomes and are moved apart

    Telophase = chromosomes gather at opposite ends of the cell and lose their distinct shapes- 2 new nuclear envelopes form

    Anaphase


    Ch 10 cell growth and division ch 11 meiosis sec 11 4

    Prophase = chromatin condenses into chromosomes, centrioles separate, spindle forms, nuclear envelope breaks down.

    Interphase = cell grows and replicates its DNA and centrioles.

    Cytokinesis = cytoplasm pinches in half, each daughter cell has an identical set of duplicate chromosomes

    Interphase

    Prophase

    I…then PMAT

    Cytokinesis

    Metaphase

    Metaphase = chromosomes line up across the center of the cell, and each is connected to a spindle fiber at its centromere

    Telophase = chromosomes gather at opposite ends of the cell and lose their distinct shapes- 2 new nuclear envelopes form

    Telophase

    Anaphase

    Anaphase = sister chromatids separate into individual chromosomes and are moved apart


    Ch 10 cell growth and division ch 11 meiosis sec 11 4

    Product of Mitosis?

    2 identical daughter cells

    Box 32

    Prophase

    Interphase

    Metaphase

    Cytokinesis

    Anaphase

    Telophase


    Cell cycle tree map

    Cell Cycle Tree Map

    Cell Cycleincludes…..

    Mitosisis divided into…

    Interphaseis divided into…

    G1 phase

    G2 phase

    S phase

    Telophase

    Prophase

    Metaphase

    Anaphase

    And then………Cytokinesis


    Ch 10 cell growth and division ch 11 meiosis sec 11 4

    Draw the cell cycle diagram on pg. Label the parts. List the stages of the cell cycle, describe what happens in each stage (G1, G2, S and M)

    Title: The Cell Cycle and Mitosis

    Your Name:ex. by Fred Cooks

    1st : The Cell Cycle & Interphase

    Prophase. Draw a cell in prophase using pg. 246 as a reference. List 3 facts describing events in Prophase.

    P

    2nd : Mitosis - Prophase

    M

    3rd : Mitosis - Metaphase

    Metaphase. Draw a cell in metaphase, and list 3 facts describing events in this phase.

    A

    4th : Mitosis - Anaphase

    T

    5th : Mitosis - Telophase

    Anaphaseand Telophase. Draw a cell in anaphase and telophase, and list 3 facts describing events in each phase.

    6th : Cytokinesis

    Include these definitions:

    Cytokinesis. Draw a cell in cytokinesis and define what happens to the cell.

    Chromosome Centromere

    Centriole Spindle

    Sister chromatids


    Regulation of the cell cycle

    Regulation of the Cell Cycle

    Section 10-3

    Box 25

    • For very obvious reasons, the cell cycle is a tightly, highly controlled process.

    • Do you know why?

    • Uncontrolled cell growth is cancer!!!Cancer can be deadly!

    • Not all cells need to divide all the time, or at all.

    • There is a time and place for cell division, and controlling the cell cycle is important because it is part of homeostasis- keeping an organism alive and healthy.

    Box 25

    Box 33

    Box 25

    Box 34


    Controls on cell division

    Controls on Cell Division

    In the lab, scientists can grow cells by placing them in a petri dish, along with nutrients.

    If you remove cells from the center of the dish, cells bordering the open space begin dividing and filling the empty space.

    Cells will grow until they form a single layer covering the bottom of the dish, then they stop growing when they come into contact with one another.

    These experiments show that controls on cell growth and division can be turned onand off.

    Box 35


    What happens in your body

    What happens in your body?

    • Similar processes happen in your own body.

    • What if you get a cut on your finger? A broken bone?

    • When you’re injured, cells at the edge of the cut or break are stimulated to divide rapidly and produce new cells, starting the process of healing.

    • When the gap is repaired, the controls for cell division turn off again, and everything returns to normal.

    Box 27

    Box 36


    Cell cycle regulators

    Cell Cycle Regulators

    • Tim Hunt and Mark Kirschner found a protein that, when injected into non-dividing cells, would cause mitotic spindle fibers to form.

    • Levels of this protein rose and fell, depending on the phases of the cell cycle – produced when needed for division, not produced when no cell division is occurring.

    • They called the protein Cyclin (for cycle)

    • Cyclins = regulate the timing of the Cell Cycle in Eukaryote cells (your cells!)

    Box 28

    Box 37

    Box 29

    Box 38


    Hunt and kirschner s experiment

    Hunt and Kirschner’s Experiment

    A sample of cytoplasm is removed from a cell in mitosis.

    Box 30

    The reason for this effect is the proteinCyclin, whichtriggers cell divisionin non-dividing cells.

    The sample is injected into a second cell in G2 of interphase.

    As a result, the second cell enters mitosis.


    Internal and external regulators

    Internal and External Regulators

    Box 31

    Box 39

    • Internal regulators = regulating proteins that respond to events inside the cell, and control the cell cycle; allow cell cycle to proceed only when certain process have happened inside the cell.

    • Similar to: You can’t eat your dessert until you clean your plate!

    • External regulators = regulating proteins that respond to events outside the cell, and control the cell cycle

    Box 32

    Box 40


    Uncontrolled cell growth

    Uncontrolled Cell Growth

    Box 42

    44.77% chance of a man getting cancer

    33.08% chance of a woman getting cancer

    • Cancer.

    • Such a scary word, isn’t it?

    • Most common cancers:

    • Men: Prostate cancer (33%)

      Lung (13%)

    • Women:Breast (32%)

      Lung (13%)

    Affects 1 in 6 men

    Box 41

    Box 33

    Affects 1 in 13 men

    Affects 1 in 7 women

    Affects 1 in 17 women

    Box 34

    Pretty frightening, yes?

    American Cancer Society 2004 Statistics


    Cancer

    Cancer

    Box 43

    Tumors = masses of uncontrollably dividing cells that damage surrounding tissues

    Box 44

    • Cancer cells may Metastasize, or break loose and spread throughout the body.

    Untreated Breast Cancer

    Tumor on the eye

    • Cancer cells do not respond to the signals that regulate growth of most cells.

    • They divide uncontrollably and form masses of cells called Tumors that can damage the surrounding tissues.

    Box 35

    Box 36


    Cancer1

    Cancer

    • Cancer is a disease of the Cell Cycle.

    • To find a cure for this horrible disease, we must first deeply and completely understand the Cell Cycle, what regulates it, and how it can go wrong, resulting in cancer.

    • This is a major scientific challenge, but at least we know now where to start searching for a cure- the Cell Cycle.

    Box 37

    Box 45


    Stem cells

    Stem Cells

    • When you were first conceived, you started out as a SINGLE cell. One cell.

    • That one cell then divided over and over, (Mitosis) producing cells that could and would become all the specialized parts of your body.

    • Fetal Stem Cells= the cells in the earliest stages of fetal (baby) development, they can potentially become any cell type in the body.

    • Adult Stem Cells = usually found in the bone marrow, can be induced (pushed) to become other cell types like muscle, nerve and liver cells

    Controversial – Unethical?

    Box 38

    Box 46

    Box 47

    Box 39

    Has the promise to repair many injuries and replace damaged organs (ex. liver)


    Meiosis

    Meiosis

    Section 11-4

    46

    Box 40

    Box 48

    • Humans have 46 chromosomes in every cell of our bodies except the sex cells or gametes (eggs and sperm)- they have 23 chromosomes

    • When a baby is conceived, an egg from mom and a sperm from dad, combine into the first cell of the new baby. 23+23 = 46

    Box 49

    Box 40

    Box 50

    46

    What would happen if the egg and sperm both had 46 chromosomes?

    Baby would have 92 chromosomes!! Disaster!

    92

    chromosomes

    = death, disease


    Remembering meiosis

    Remembering Meiosis

    Box 51

    • Mitosis is a process that occurs in almost every cell of your body (body cells), except the sex cells, or gametes.

    • Mitosis = My toe sis, it happens in your toes!

    • Meiosis is a process of cell division that doesn’t happen in your toes, it only happens in your sex cells, gametes

    • Meiosis = My OH! Sis (as in uh-oh!)

    Box 40

    Box 52


    Meiosis1

    Meiosis

    Box 55

    Meiosis results in cells with ½ the # of chromosomes, so they can combine in sexual reproduction, which results in an embryo with the normal amount of chromosomes.

    • To solve this problem, the cells in the gametes (eggs and sperm), undergo Meiosis instead of Mitosis, when they divide.

    • Why Meiosis?

    • Most cells in our body are Diploid (“di” = 2)

    • Diploid = have 2 sets of chromosomes, 2n(one from mom, one from dad)

    • Sex cells, or gametes, are Haploid

    • Haploid = have 1 set of chromosomes, 1n

    Box 53

    Box 41

    Box 54

    Box 42


    Chromosome number

    Chromosome Number

    Box 56

    Homologous chromosomes= 2 sets of similar chromosomes, one from mom, one from dad

    • An example.

    • Fruit Flies (Drosophila), have 8 chromosomes total – 4 from dad fruit fly, 4 from mom fruit fly.

    Box 43

    2n = 8

    Diploid number?

    Haploid number?

    1n = 4


    Phases of meiosis

    Phases of Meiosis

    Homologous = same chromosome, it just comes from different parents (mom or dad)

    • How are haploid (1n) gamete cells produced from diploid (2n) cells?

    • By Meiosis (my-OH-sis)

    • Meiosis = process of reduction cell division where the # of chromosomes per cell is cut in ½ by the separation of homologous chromosomes

    Box 57

    Box 45

    Box 58

    Box 46

    • Meiosis involves 2 distinct divisions,

    • Meiosis I

    • Meiosis II

    • Results of Meiosis? = cells with a haploid (1n) number of chromosomes

    Box 59


    Meiosis i

    Meiosis I

    Box 61

    Prophase I = Each chromosome pairs up with its matching homologous chromosome forming a tetrad

    Interphase I = Cells undergo a round of DNA replication, forming duplicate chromosomes

    Tetrads= in prophase I, chromosomes duplicate and form a structure with 4 chromosomes (tetrad)

    Box 60

    Box 62

    4 sister chromatids form a Tetrad

    2 sister chromatids

    Interphase I

    Prophase I

    Chromosome duplication


    Ch 10 cell growth and division ch 11 meiosis sec 11 4

    During prophase I of Meiosis, when the tetrads form, a phenomenon called “Crossing Over” can occur.

    Crossing Over = results in the exchange of genetic information between homologous chromosomes

    Box 63

    You got peanut butter in my chocolate!

    You got chocolate in my peanut butter!

    Sorry!

    Hey hot stuff, wanna dance?

    Owww! My arm!

    Who me?

    I think he likes me!

    Help!


    Meiosis i1

    Meiosis I

    Anaphase I = Fibers pull the homologous chromosomes towards opposite ends of the cell (“A” for apart)

    Prophase I = Each chromosome pairs up with its corresponding homologous chromosome to form a tetrad

    Box 64

    Metaphase I = Spindle fibers attach to the chromosomes, then they line up in the middle (“M” for middle)

    Interphase I = Cells undergo a round of DNA replication, forming duplicate chromosomes

    Box 65

    Interphase I

    Prophase I

    Metaphase I

    Anaphase I


    Meiosis i2

    Meiosis I

    Anaphase I = Fibers pull the homologous chromosomes towards opposite ends of the cell (“A” for apart)

    Prophase I = Each chromosome pairs up with its corresponding homologous chromosome to form a tetrad

    Metaphase I = Spindle fibers attach to the chromosomes, then they line up in the middle (“M” for middle)

    Telophase I and Cytokinesis = Nuclear membranes form, the cell separates into 2 new cells

    Interphase I = Cells undergo a round of DNA replication, forming duplicate chromosomes

    Box 66

    Interphase I

    Prophase I

    Metaphase I

    Anaphase I

    Telophase and Cytokinesis


    Meiosis ii

    Meiosis II

    Prophase II = of meiosis I results in 2 haploid daughter cells, each with ½ the # of chromosomes as the original cell

    Box 67

    The 2 new cells now enter a 2nd round of meiotic division

    No more chromosome duplication

    prophase II


    Meiosis ii1

    Meiosis II

    Metaphase II = chromosomes line up in the middle

    Box 68

    metaphase II

    prophase II

    Prophase II = of meiosis I results in 2 haploid daughter cells, each with ½ the # of chromosomes as the original cell


    Meiosis ii2

    Meiosis II

    Anaphase II = sister chromatids separate and move to opposite ends of the cell

    Box 69

    Prophase II = of meiosis I results in 2 haploid daughter cells, each with ½ the # of chromosomes as the original cell

    Metaphase II = chromosomes line up in the middle

    Telophase II and Cytokinesis = of meiosis II results in 4 haploid (1n) daughter cells

    Box 70

    4

    3

    metaphase II

    anaphase II

    telophase II

    prophase II

    2

    1


    Ch 10 cell growth and division ch 11 meiosis sec 11 4

    Flow Chart for Meiosis

    I

    P

    Interphase I

    M

    Prophase I

    A

    Metaphase I

    Anaphase I

    T

    92

    Telophase I

    &Cytokinesis

    92

    92

    92

    Humans = 2n = 46

    46

    P

    Prophase II

    A

    M

    T

    Telophase II

    &

    Cytokinesis

    Anaphase II

    Metaphase II

    46

    23

    46

    46

    4 daughter cells

    with haploid # (1n)

    I then …PMAT…..PMAT


    Gamete formation

    Gamete Formation

    For Sexual Reproduction, where egg and sperm unite to make an embryo

    Box 72

    • Why do we even have Meiosis?

    • To make gametes (eggs and sperm).

    • Male gametes = sperm

    • Female gametes = eggs

    Box 71

    Skip Box 59

    Why do we need eggs and sperm?

    End of Chapter 10 and Chapter 11 Section 11-4


  • Login