CELL REPRODUCTION SB1. Students will analyze the nature of relationships between structures and functions in living things a. Explain the role of cell organelles for both prokaryotic and eukaryotic cell in cell reproduction

VOCABULARY DIPLOID CELL GAMETE MEIOSIS CARCINOGENS APOPTOSIS CELL DIVISION MITOSIS INTERPHASE CYTOKINESIS SOMATIC CELLS CELL CYCLE CHROMOSOME CANCER MEIOSIS I MEIOSIS II GAMETOGENESIS HOMOLOGOUS CHROMOSOMES TUMOR BENIGN DIPLOID CELL GAMETE MEIOSIS CARCINOGENS APOPTOSIS CLEAVAGE FURROW CELL PLATE CELL REPRODUCTION PROPHASE METAPHASE ANAPHASE TELOPHASE GROWTH FACTORS MALIGNANT

LEQ: What are the two types of cellular reproduction?

Cell Reproduction Each organism has a specific number of chromosomes Made of DNA store/transfer genetic info If the chromosome number is not maintained from generation to generation mutations may evolve. Humans have 46 chromosomes

Cell Reproduction Two types of cell division maintain chromosome number from generation to generation: Mitosis Meiosis

MITOSIS Process by which a cell divides its nucleus and contents Produces diploid cells from diploid cells Cell that contains two copies of each chromosome, one from mother and one from father. Occurs in somatic/body cells

Cell Reproduction Cell Cycle The cell cycle is a regular pattern of growth, DNA replication, and cell division The cell cycle has four main stages Gap 1 (G1) DNA Synthesis (S) Gap 2 (G2) Mitosis (M) INTERPHASE

The Cell Cycle 4 Stages Main Stages: Gap1 (G1) DNA synthesis (S) Cell growth & normal functions DNA synthesis (S) Copies DNA Gap2 (G2) Additional growth, DNA checkpoint Mitosis (M) Includes division of cell nucleus (mitosis) and division of cytoplasm (cytokinesis) Only occurs if the cell is large enough and the DNA undamaged.

The Cell Cycle Interphase prepares the cell to divide (G1, S, G2) During interphase, the DNA is duplicated. Interphase is followed by Mitosis and cytokinesis (M) Mitosis and cytokinesis produce two genetically identical daughter cells. Parent cell centrioles spindle fibers centrosome nucleus with DNA

The Cell Cycle Mitosis (M) Mitosis divides the cell’s nucleus in four phases: Prophase Metaphase Anaphase Telophase

The Cell Cycle Phases of Mitosis During Prophase, chromosome condense and spindle fibers form. Centrioles Spindle fibers

The Cell Cycle Phases of Mitosis During Metaphase, chromosome line up in the middle of the cell. Metaphase Plate

The Cell Cycle Phases of Mitosis During Anaphase, sister chromatids separate to opposite sides of the cell.

The Cell Cycle Phases of Mitosis (M) During Telophase, the new nuclei form and chromosomes begin to uncoil. Cleavage Furrow

The Cell Cycle Cytokinesis Cytokinesis differs in animal and plant cells Division of cytoplasm In animal cell, the membrane pinches closed (forms a cleavage furrow) In plant cell, a cell plate forms to separate cells.

The Cell Cycle Cytokinesis Animal Cell Plant Cell Cell Plate Cleavage Furrow

MEIOSIS Process that divides a diploid cell into haploid cells Cell that only has one set of chromosomes Important in forming gametes for sexual reproduction Sex cell (egg or sperm cell) Occurs in sex cells of reproductive organs

Process of Meiosis During Meiosis, diploid cells undergo two cell divisions that result in haploid cells Role of Meiosis: Reduces chromosome number Increase genetic diversity

Process of Meiosis Cell go through two rounds of division Meiosis I Meiosis II Each have four phases similar to mitosis

Process of Meiosis Meiosis I Occurs after DNA has been replicated Divides homologous chromosomes in 4 phases. Homologous chromosomes are similar but not identical. - Code for same traits homologous chromosomes MOM DAD Anaphase Telophase Prophase Metaphase

Process of Meiosis Meiosis II Divides sister chromatids in four phases. Sister chromatids are copies of the same chromosome. DNA is not replicated between meiosis I and II. sister chromatids Prophase II Metaphase II Anaphase II Telophase II

Process of Meiosis Haploid cells created by meiosis develop into mature gametes. Gametogenesis is the production of gametes. Differs between females and males

Process of Meiosis Sperm become streamlined and motile Sperm primarily contribute DNA to embryo The egg gets most of the contents; the other cells form polar bodies Egg contributes DNA, cytoplasm, & organelles to embryo

Similar to mitosis, but there are some important differences Mitosis vs. Meiosis Similar to mitosis, but there are some important differences Mitosis Produces 2 genetically identical somatic cells Produces diploid cells Undergoes 1 cell division Meiosis Produces 4 genetically different germ cells Produces haploid cells Undergoes 2 cell divisions Meiosis I, Meiosis II

Concept Check: Meiosis produces human cells with how many chromosomes? 44 23 46 15

Concept Check 4. Two similar chromosomes that you inherit from your parents ( one from your mother, one from you father) are called a. homologous chromosomes b. sister chromatids c. sex chromosomes d. homozygous alleles

Concept Check 5. Which of the following cell types is diploid? a. sex cell b. gamete c. sperm cell d. zygote

Regulation of Cell Reproduction Cell cycle regulation is necessary for healthy growth. Internal and external factors regulate cell division

The Cell Cycle Cells divide at different rates. The rate of cell division varies with the need for those types of cells Some cells are unlikely to divide.

The Cell Cycle Cell size is limited Volume increases faster than surface area. Cell growth is coordinated with division

The Cell Cycle Surface Area Surface area must allow for adequate exchange of materials Cells that must be large have unique shapes

The Cell Cycle Regulation External factors include physical and chemical signals Example: growth factors are proteins that stimulate cell division. Most mammal cells form a single layer in a culture dish an stop dividing once they tough other cells.

The Cell Cycle Regulation Internal factors regulate growth from inside the cell Two of the most important: Kinases Cyclins Internal factors are triggered by external factors, both of which will affect the cell cycle.

The Cell Cycle Regulation Apoptosis is programmed cell death. Normal feature in healthy organisms Caused by a cell’s production of self-destructive enzymes Occurs in development of infants. webbed fingers

The Cell Cycle Regulation Cell division is uncontrolled in cancer Cancer cells form disorganized clumps called tumors Cancer cells do not carry out necessary functions Cancer cells come from normal cells with damage to genes involved in cell cycle regulation.

The Cell Cycle Regulation Benign tumors remain clustered and can be removed. Malignant tumors metastasize, or break away, and can form more tumors.

The Cell Cycle Regulation Carcinogens are substances known to promote cancer Standard cancer treatments typically kill both cancerous and healthy cells.

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