Bell Work February 27, 2013

What happened here?

What about this?

Objectives Sequence a series of diagrams that depict chromosome movement during plant cell division. (SPI )Sequence a series of diagrams that depict chromosome movement during plant cell division. (SPI ) Classify methods of reproduction as sexual or asexual. (SPI )Classify methods of reproduction as sexual or asexual. (SPI )

Mitosis Review 1.Interphase- DNA is copied 2.Prophase- Chromatin (DNA wrapped around protein) forms into chromatids 3.Metaphase- Chromatids line up in the middle of the cell 4.Anaphase- Chromatids separate 5.Telophase- two new nuclei form around the chromatin 6.Cytokinesis- two new cells form

Housekeeping 1. if you have old missing work I will need to see it very soon. 2. make sure you are gluing the sheets in that we do each day. 3. make sure you take responsibility for your learning and look over the things we study in class. It should not only be seen when I teach it.

Mitosis: process of a somatic (body) cell dividing to produce an exact copy of itself

Vocabulary Chromatin is a mass of genetic material composed of DNA and proteins that condense to form chromosomes.

A centromere is a region on a chromosome that joins two sister chromatids. A chromosome is a long, stringy aggregate of genes that carries heredity information and is formed from condensed chromatin. Chromatid is one-half of two identical copies of a replicated chromosome.

Relationship between chromosomes, genes, and DNA DNA is coiled up in the chromosomes so that it will fit! Chromosomes are filled with bundled up DNA. DNA contains genes.

Create the Phases of Mitosis Use the cards at your group to sequence a series of diagrams that depict chromosome movement during cell division (mitosis) on your desk. Label each box with the phase name and draw each phase in the boxes on your note sheet.Use the cards at your group to sequence a series of diagrams that depict chromosome movement during cell division (mitosis) on your desk. Label each box with the phase name and draw each phase in the boxes on your note sheet.

Mitosis Interphase DNA is copied (in chromatin form) Centrioles copy Animal Cell Plant Cell chromatin

MitosisProphase DNA condenses into chromatids Spindle fibers begin to form Centrioles move to opposite sides Nuclear membrane breaks apart Animal Cell Plant Cell chromatids

MitosisMetaphase Chromatids (chromosomes) line up across the center of the cell Spindle fibers attach to the centromeres (center of the chromsome) Animal Cell Plant Cell spindle fibers

MitosisAnaphase Spindle fibers pull the chromatids to opposite ends of the cell Animal Cell Plant Cell

MitosisTelophase Two new nuclei form around the chromatids Chromosomes unwind back into chromatin Animal Cell Plant Cell Cytoplasm still attached

MitosisCytokinesis Division of the cytoplasm and the rest of the cell Two new daughter cells! Animal Cells Plant Cells

In sexual reproduction, two parent cells join together to form offspring that are different from both parents. These parent cells are called sex cells (sperm & egg). Sex cells are made during meiosis. Meiosis

Challenge Question If sex cells, created during meiosis, are part of sexual reproduction where two parent cells join together to form offspring that are different from both parents, what type of reproduction would the cells in mitosis be a part of if they come from one cell and are identical to the parent cell? ASEXUAL REPRODUCTION

Meiosis process of a cell dividing to produce 4 cells with half the genetic material Why do the cells produced in meiosis only need half of the genetic material?

Meiosis Interphase I DNA copies Centrioles copy

Meiosis Prophase I DNA organized into chromatids Spindle fibers form Centrioles move to opposite sides Nuclear membrane breaks apart

Meiosis Metaphase I Chromatids line up on each side of the center of the cell Spindle fibers attach chromosomes Meiosis is a bit different because there something called crossing-over happens with the DNA. This crossing over is an exchange of genes. The genes are mixed up, not resulting in a perfect duplicate like mitosis.

Meiosis Anaphase I Spindle fibers pull the chromosome pairs apart to opposite ends of the cell

Meiosis Telophase I Two new nuclei form Chromosomes unwind (chromatin)

MeiosisCytokinesis Cytoplasm splits Two cells

Predict what happens next in Interphase II CytokinesisInterphase II Keep in mind the four cells at the end of meiosis only get HALF of the genetic material…

Meiosis Interphase II Cell rests DNA DOES NOT duplicate Centrioles duplicate

Meiosis Prophase II DNA organized into chromatids Spindle fibers form Centrioles move to opposite sides Nuclear membrane breaks apart

Meiosis Metaphase II Chromosomes line up across the center of the cell Spindle fibers attach to the chromosomes

Meiosis Anaphase II Spindle fibers pull the chromatids to opposite ends of the cell

Meiosis Telophase II Two new nuclei form around the chromatids Chromosomes unwind (chromatin)

MeiosisCytokinesis Cytoplasm splits 4 new cells! Each cell with only half of the genetic information

Mitosis vs. Meiosis Give one similarity and one difference for Mitosis and Meiosis.