Ch. 10 – Cell Division and Growth Cell Growth usually involves an organism making MORE cells. The size a cell reaches is limited by the cell’s surface area to volume ratio. As the cell grows, its surface area doesn’t grow as quickly as its volume does (therefore, its surface area to volume ratio DECREASES as it grows in size).

Cell Size Surface Area (length x width x 6) Volume (length x width x height) Ratio of Surface Area to Volume Ratio of Surface Area to Volume in Cells Section 10-1 Go to Section:

If a cell gets too big, the surface area of its membrane cannot bring oxygen and nutrients fast enough to meet the needs of its volume. The cell will divide when it gets too big through a process called mitosis. Cell growth can also be limited by nutrient availability and space. Cell division can be regulated by proteins called kinases. Uncontrolled cell growth can result in cancer.

M phase G 2 phase S phase G 1 phase Figure 10–4 The Cell Cycle Section 10-2 Go to Section:

Holds sister chromatids together in the middle. Two identical, “sister” chromatids. Chromosome structure before cell division.

PROPHASE

METAPHASE

Centrioles Chromatin Interphase Nuclear envelope Cytokinesis Nuclear envelope reforming Telophase Anaphase Individual chromosomes Metaphase Centriole Spindle Centriole Chromosomes (paired chromatids) Prophase Centromere Spindle forming Section 10-2 Figure 10–5 Mitosis and Cytokinesis Go to Section:

Centrioles Chromatin Interphase Nuclear envelope Cytokinesis Nuclear envelope reforming Telophase Anaphase Individual chromosomes Metaphase Centriole Spindle Centriole Chromosomes (paired chromatids) Prophase Centromere Spindle forming Section 10-2 Figure 10–5 Mitosis and Cytokinesis Go to Section:

Centrioles Chromatin Interphase Nuclear envelope Cytokinesis Nuclear envelope reforming Telophase Anaphase Individual chromosomes Metaphase Centriole Spindle Centriole Chromosomes (paired chromatids) Prophase Centromere Spindle forming Section 10-2 Figure 10–5 Mitosis and Cytokinesis Go to Section:

Centrioles Chromatin Interphase Nuclear envelope Cytokinesis Nuclear envelope reforming Telophase Anaphase Individual chromosomes Metaphase Centriole Spindle Centriole Chromosomes (paired chromatids) Prophase Centromere Spindle forming Section 10-2 Figure 10–5 Mitosis and Cytokinesis Go to Section:

Centrioles Chromatin Interphase Nuclear envelope Cytokinesis Nuclear envelope reforming Telophase Anaphase Individual chromosomes Metaphase Centriole Spindle Centriole Chromosomes (paired chromatids) Prophase Centromere Spindle forming Section 10-2 Figure 10–5 Mitosis and Cytokinesis Go to Section:

Centrioles Chromatin Interphase Nuclear envelope Cytokinesis Nuclear envelope reforming Telophase Anaphase Individual chromosomes Metaphase Centriole Spindle Centriole Chromosomes (paired chromatids) Prophase Centromere Spindle forming Section 10-2 Figure 10–5 Mitosis and Cytokinesis Go to Section:

includes is divided into Section 10-2 Cell Cycle M phase (Mitosis) Interphase G 1 phaseS phaseProphaseG 2 phaseMetaphaseTelophaseAnaphase Go to Section:

Link to animation review of meiosis hill.com/sites/ /student_view0/chapter3/ animation__how_meiosis_works.html Link to animation of mitosis/meiosis comparison hill.com/sites/ /student_view0/chapter3/anima tion__comparison_of_meiosis_and_mitosis__quiz_1_.ht ml link to mitosis animation Sea Star regeneration Fruit Tree Grafting

Budding in Hydra

There are 2 types of Reproduction: AsexualSexual________ One parent contributes Genetic info. to offspring Two parents contribute genetic info. to offspring Offspring are identical to each other an parent Offspring are similar to each other an parent Mitosis is used to make offspring cells Meiosis is used by each parent to make sex cells called gametes which fuse into a cell that grows into offspring. Ex: animals, plants Ex: plants, some animlas, protists, bacteria

MEIOSIS Meiosis is a special type of cell division used to make sex cells called gametes. Meiosis is used to give sex cells half the species' normal chromosome number.

Background Information on Chromosomes - Humans have 46 chromosomes in each body cell. - These 46 chromosomes are organized into 23 pairs. These are known as homologous pairs. - In each pair humans have, one of the chromosomes was donated from mom's egg and one from dad's sperm.

Pairs of chromosomes contain information for the same types of traits. During meiosis, homologous chromosomes will be separated and only one will be passed to each sex cell that is made.

Meiosis I Interphase I Prophase I Metaphase I Anaphase I Cells undergo a round of DNA replication, forming duplicate Chromosomes. Each chromosome pairs with its corresponding homologous chromosome to form a tetrad. Spindle fibers attach to the chromosomes. The fibers pull the homologous chromosomes toward the opposite ends of the cell. Section 11-4 Figure Meiosis Go to Section:

Meiosis I Interphase I Prophase I Metaphase I Anaphase I Cells undergo a round of DNA replication, forming duplicate Chromosomes. Each chromosome pairs with its corresponding homologous chromosome to form a tetrad. Spindle fibers attach to the chromosomes. The fibers pull the homologous chromosomes toward the opposite ends of the cell. Section 11-4 Figure Meiosis Go to Section:

Meiosis I Interphase I Prophase I Metaphase I Anaphase I Cells undergo a round of DNA replication, forming duplicate Chromosomes. Each chromosome pairs with its corresponding homologous chromosome to form a tetrad. Spindle fibers attach to the chromosomes. The fibers pull the homologous chromosomes toward the opposite ends of the cell. Section 11-4 Figure Meiosis Go to Section:

Meiosis I Interphase I Prophase I Metaphase I Anaphase I Cells undergo a round of DNA replication, forming duplicate Chromosomes. Each chromosome pairs with its corresponding homologous chromosome to form a tetrad. Spindle fibers attach to the chromosomes. The fibers pull the homologous chromosomes toward the opposite ends of the cell. Section 11-4 Figure Meiosis Go to Section:

Meiosis II Meiosis I results in two haploid (N) daughter cells, each with half the number of chromosomes as the original. Prophase IIMetaphase IIAnaphase IITelophase II The chromosomes line up in a similar way to the metaphase stage of mitosis. The sister chromatids separate and move toward opposite ends of the cell. Meiosis II results in four haploid (N) daughter cells. Section 11-4 Figure Meiosis II Go to Section:

Meiosis II Meiosis I results in two haploid (N) daughter cells, each with half the number of chromosomes as the original. Prophase IIMetaphase IIAnaphase IITelophase II The chromosomes line up in a similar way to the metaphase stage of mitosis. The sister chromatids separate and move toward opposite ends of the cell. Meiosis II results in four haploid (N) daughter cells. Section 11-4 Figure Meiosis II Go to Section:

Meiosis II Meiosis I results in two haploid (N) daughter cells, each with half the number of chromosomes as the original. Prophase IIMetaphase IIAnaphase IITelophase II The chromosomes line up in a similar way to the metaphase stage of mitosis. The sister chromatids separate and move toward opposite ends of the cell. Meiosis II results in four haploid (N) daughter cells. Section 11-4 Figure Meiosis II Go to Section:

Meiosis II Meiosis I results in two haploid (N) daughter cells, each with half the number of chromosomes as the original. Prophase IIMetaphase IIAnaphase IITelophase II The chromosomes line up in a similar way to the metaphase stage of mitosis. The sister chromatids separate and move toward opposite ends of the cell. Meiosis II results in four haploid (N) daughter cells. Section 11-4 Figure Meiosis II Go to Section:

Meiosis II Meiosis I results in two haploid (N) daughter cells, each with half the number of chromosomes as the original. Prophase IIMetaphase IIAnaphase IITelophase II The chromosomes line up in a similar way to the metaphase stage of mitosis. The sister chromatids separate and move toward opposite ends of the cell. Meiosis II results in four haploid (N) daughter cells. Section 11-4 Figure Meiosis II Go to Section:

Meiosis Vocabulary Synapsis - A process where homologous chromosomes pair up with each other during prophase I Tetrad - A structure formed from "paired up" homologous chromosomes. XX

Diploid - A term used to describe the normal species chromosome number (for organisms with their chromosomes in pairs). The human diploid number is 46. Haploid (n)- A term used to describe a cell with one copy of each type of chromosome.

There are 2 ways that meiosis introduces variety into sex cells: 1. Independent Assortment – a process where the homologous pairs of chromosomes can line up on either side of the metaphase plate. For example: XXXX X = mom donated X = dad donated XXXX

Section 11-4 Crossing-Over Go to Section: 2. Crossing Over: A process where homologous chromosomes cross over and exchange chromosome parts during meiosis I.

Meiosis is different in females and males: MalesFemales