Ch 8.2 Cell Growth and Reproduction Hickox: Baker High School Biology

Ch 8.2 Cell Growth and Division Opening Question: When a baby grows, what happens to his or her cells? 1)Does each of the cells get larger too? 2) Are there more cells? The Cells Divide rather than grow larger! 3) The volume increases faster than the surface area 4) Homeostasis is disrupted by a cell that is too large! Hickox: Baker High School Biology

Ch 10 Cell Growth and Division Cell Division 5) Before the cell becomes too large, it divides forming two ___________ cells. 6) Before cell division, all of the ______ replicates or copies itself. Hickox: Baker High School Biology 7) Two reasons cells divide rather than grow in size 8) The __________ increases faster than the _________________ 9) ________________ is disrupted by a cell that is too large!

Ch 10 Cell Growth and Division Remember from cell theory: 10) All cells come from ___________ cells! 11) This is _____ division, or __________, these two cells that are identical to the original _________ cell 12 The exact copy of the parent is called a ___________ cell. Hickox: Baker High School Biology

Ch 8-2 Cell Division 13)In eukaryotic cells, the ________ information is passed on from one generation to the next generation by strands of DNA called ___________ Most of a cell’s lifetime, chromosomes exist as Chromatin, granular material in the nucleus 14)Chromosomes are made up of _______, which carries the cells genetic information and proteins 15)Humans have ______ chromosomes or ___pairs 16)Chromosomes are not visible except during cell division 17)Before cell division the chromosomes condense into compact, visible structures that can be seen (compound light microscope) Hickox: Baker High School Biology

The Cell Cycle Chapter 10 MEIOSIS GAMETES (sex cells) Egg and sperm *There are _______ types of cell division… MITOSIS produces exact copies of the__________ These cells are called _____________ cells These cells are called _____________ cells Hickox: Baker High School Biology

18. Draw the Chromosome Structure as shown on page 205. Include by labeling the following terms: Sister Chromatids, Centromere, and Chromosome

8- 2 The Cell Cycle 8.2 CHROMOSOME CHROMATID SISTER CHROMATIDS CENTROMERE “Structure” TETRAD Hickox: Baker High School Biology

Duplicated Chromosomes Hickox: Baker High School Biology 19) A Tetrad: consists of two (2) homologous chromosomes, each made up of two sister chromatids. The chromatids in a tetrad pair coil tightly and allow for crossing over (only in meiosis).

8 – 2 Mitosis: Cell 8.2 Mitosis 20) Parent cell produces two daughter cells. 21) Each daughter cell gets a copy, thus each daughter cell is genetically identical to each other and to the parent cell 22) Mitosis is made up of several phases: 23) Prophase 24) Metaphase 25) Anaphase 26) Telophase Mitosis starts with chromosomes doubling and condensing During mitosis, sister chromatids separate and are identical to each other and to parent cell. Hickox: Baker High School Biology

Ch 8.2 Cell Cycle The Cell Cycle 23) The “in-between” periods of cell growth are called ___________. 24) The cell _________ is the series of events that cells go through as they grow and divide. Hickox: Baker High School Biology During Interphase: 25) The cell grows in size and carries on metabolism. 26) Chromosomes are duplicated!

Prophase ) Prophase - The Preparation Phase (longest phase) 27) Prophase - The Preparation Phase (longest phase) 28) Chromosomes 28) Chromosomes become visible 29) Chromosomes 29) Chromosomes are coiled tightly. 30) Nucleolus disappears 31) CENTRIOLES appear with spindle fibers. 32) SPINDLE 32) SPINDLE forms a microtubule structure that helps separate chromosomes 33) This is the first time __________ can be seen using a compound light microscope. Hickox: Baker High School Biology

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Metaphase: Second stage of Mitosis 8.2 Metaphase 34) (movement to equator) midline or equator. 35) Chromosomes line up along an imaginary plane called the midline or equator. 36) Chromosomes are pulled by the spindle fibers and begin to line up on midline or equator. 37) Centrioles complete migration to opposite poles Hickox: Baker High School Biology

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Anaphase: The third phase of mitosis 8.2 Anaphase (38) ( separation) 39) Centromeres split and the sister chromatids are pulled towards opposite poles of the cell 40) Spindle fibers shorten  pulls them apart 41) The two groups near the poles of the spindle Hickox: Baker High School Biology

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Telophase: the fourth phase of mitosis 8.2 Telophase 42) Chromatids reach the opposite poles of the cell 43) Chromosomes unwind and begin metabolism. 44) Spindle begin to break down 45) New Nuclear membrane form Hickox: Baker High School Biology

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Cytokinesis ) CYTOKINESIS: the cell’s cytoplasm divides into two daughter cells. 47) Typically occurs immediately after mitosis 48) In animals  C CC CLEAVAGE FURROW 49) In plants  C CC CELL PLATE Hickox: Baker High School Biology

Cytokinesis in Animal Cells Hickox: Baker High School Biology

Phases of Mitosis in Plant Cells Hickox: Baker High School Biology

Mitosis & Cytokinesis 8.2 Hickox: Baker High School Biology

Ch 8 -3 Regulating the Cell Cycle Hickox: Baker High School Biology

An Overview of Meiosis and Mitosis Hickox: Baker High School Biology 50) Meiosis is the process that produces sex cells, the _______ in males and the _________ in females. sperm (1n)

An Overview of Meiosis and Mitosis 51) During Meiosis the number of chromosomes is reduced by half. This chromosome number is called __________ (half) or ______. 52) A diploid cell is a ____________ cell. (skin cells, nerve cells, muscle cells, etc) 53) A haploid cell contains only one of each kind of ___________. A __________, or sex cell, is a haploid cell (eggs and sperms) 54) Every living thing has a set number of chromosomes. For example, every has 78 chromosomes, Every person has 46 chromosomes and every tomato plant has 24 chromosomes The number of chromosomes does not relate to how complex an organism is

An Overview of Meiosis and Mitosis Hickox: Baker High School Biology 55) When organisms reproduce, it only passes on _________ the number of chromosomes. 56) In a diploid cell, the two chromosomes of each pair are called ____________ ________ sperm (n)

Homologous Pairs 57) Homologous chromosomes (homologues) are paired chromosomes that code for the same traits (one inherited from each (58) parent). Hickox: Baker High School Biology

How does a diploid cell become a haploid cell Hickox: Baker High School Biology 59) _____________ produces gametes containing ______ the number of chromosomes as the parent’s body. 60) Meiosis is actually _______ separate division, ______ and ____________. 61) The whole process begins with one diploid cell (2n) and ends with _____ haploid cells. The haploid cells are gametes. When the egg and sperm unites the _______ becomes a multicellular organism, in a process called _________ reproduction

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The Phases of Meiosis 62) Before meiosis begins, the chromosomes in a cell are replicated or copied. Each chromosome consist of ______ sister chromatids connected by a __________ Interphase: cell growth (2n) has nucleolus Hickox: Baker High School Biology Prophase I: DNA coils up and spindle forms Chromosomes pair up

Hickox: Baker High School Biology Prophase I: Metaphase I: move to middle along equator 63) Crossing Over: Pieces of chromatid can break off from the other homologous chromosome and genetic information can be exchanged. Genetic Recombination

Crossing-Over Hickox: Baker High School Biology

Meiosis I Hickox: Baker High School Biology Anaphase I: separation Telophase I: spindle fibers break down and chromosomes uncoil, now there are two cells both (2n) diploid number.

Meiosis II: (second division) Hickox: Baker High School Biology Prophase II: Spindle forms in each new cell, attaches to centromere of chromosomes Metaphase II: Movement to midline

Hickox: Baker High School Biology Anaphase II: Separation and movement to poles Telophase II; Cytoplasm separates and now there are four daughter cell with haploid number of chromosomes Meiosis II: (second division)

Meiosis Overview Hickox: Baker High School Biology 2n n n

Cell Cycle 39

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Ch 8 -3 Control of the Cell Cycle Hickox: Baker High School Biology Normal Control of the Cell Cycle The cell cycle is controlled by conditions both inside the cell and in the cell’s environment. When something goes wrong with normal cell conditions, cells lose control of the cell cycle. Cancer is a growth that occurs when uncontrolled cell division take place. The loss of control may be caused by a change in enzyme production inside the cell or outside conditions, such as air or water pollution. Enzyme: type of protein that changes the rate of chemical reactions

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Cancer: A mistake in the Cell Cycle Hickox: Baker High School Biology Scientists think cancer is caused by changes to one or more of the genes that control the cell cycle. A gene is a part of the DNA that controls the production of a protein. Cancer occurs when something causes the damaged genes to go into action (SMOKING). Cancer cells then form masses of tissues called tumors. Tumors keep normal cells from getting needed nutrients. This caused organ damage. Cancer can spread throughout the body to other organs. Lung Cancer (smoker) Clean Lung (non- smoker)

What are the causes of cancer? Hickox: Baker High School Biology Cancer is the second leading cause of DEATH in the United States. Environmental factors include: cigarette smoke air and water pollution exposure to ultraviolet radiation from sun viral infections that damage the genes Lung Cancer (smoker) Skin cancer (sun exposure)

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Cytokinesis Cleavage furrow Animals only, not plants! Hickox: Baker High School Biology

Centrisome Spindle fibers Prophase Chromosomes- Thicken, double, are visible, nucleolus and nuclear membrane disappear Interphase – cell growth Hickox: Baker High School Biology

Anaphase: Hickox: Baker High School Biology

Prophase: Hickox: Baker High School Biology

Metaphase: Hickox: Baker High School Biology

Telophase: Hickox: Baker High School Biology

Prophase: Hickox: Baker High School Biology

Hickox: Baker High School Biology

Mitosis

Hickox: Baker High School Biology Meiosis I

Meiosis II Hickox: Baker High School Biology