Question of the Day How are autosomal cells and sex cells different? 2-25 How are autosomal cells and sex cells different?

Objectives Describe shape / function of a chromosome Describe differences between autosome & sex chromosomes.

Review 2-25 What am I? What am I? What am I? What am I?

Review Describe the structure of a chromosome. Identify the differences in structure between prokaryotic chromosomes and eukaryotic chromosomes. Compare the numbers of chromosomes in different species. Explain the differences between sex chromosomes and autosomes. Distinguish between diploid and haploid cells.

Sex Chromosome Abnormalities Female Genotype Syndrome Male Genotype XX normal XY XO Turner  XXY Klinefelter XXX Triple-X XYY  

Question of the Day 2-28 What is the same about a homologous pair of chromosomes? What is different?

ASSIGNMENTS Book Questions (page 5) Cell Division Webquest

REVIEW What does a chromosome look like right before cell division? What’s a histone? How is a prokaryote different than a eukaryote? Which cells are haploid? Diploid?

Cell Division Cell division – is the process by which cells reproduce. In Prokaryotes: Binary fission – Division of a prokaryotic cell into 2 offspring cells.

In Eukaryotes: Cell Cycle Cycle consisting of cell division and interphase Cell division Process of creating a new cell Includes mitosis and cytokinesis. Interphase Time between cellular division Majority of the life cycle of a cell

Interphase Cell is preparing for next division

3 Parts of Interphase: G1 -- Cell Growth (duplicate organelles) S -- DNA replication G2 -- Growth and preparation for cell division G0 – cells that do not again prepare for replication – basically stay in G1 phase

REVIEW Binary fission = ??? Two main parts of cell cycle in eukaryotes = 3 parts of interphase = ???

Cell Division – Mitosis and Cytokinesis Mitosis – Process which ONE cell divides into TWO genetically identical cells – Asexual reproduction 4 Stages: Prophase Metaphase Anaphase Telophase

Prophase Chromatin coils into chromosomes (remember DNA was duplicated in the S phase) Nuclear membrane breaks down Centrioles appear and move towards poles of cell Spindle fibers appear. Spindle fibers = microtubules that radiate from centrioles and attach to chromosomes centrioles spindle fibers chromosomes nuclear membrane

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Question of the Day 1. What are the four phases of mitosis? 3-1 1. What are the four phases of mitosis? 2. What happens during prophase? Objective: Discuss what happens in anaphase and telophase

Review 1. How are chromosomes different from chromatin? 3-1 2. What are the 2 main stages of the cell cycle? What are the 3 main stages of interphase? What happens during each stage of interphase? What are the 2 main parts of cell division? 3-1

Metaphase Spindles move sister chromatids to the equator of the cell

Metaphase chromosomes centrioles spindle fibers

Anaphase Sister chromatids pulled apart into daughter chromatids Daughter chromatids move towards poles of cell

Anaphase sister chromatids centrioles spindle fibers

Telophase Chromosomes unwind Nucleus reforms Spindles disappear Cleavage furrow appears – indentation where cells will split

Telophase cleavage furrow nuclear membrane spindle fibers

Cytokinesis Animal Cells Plant Cells Cleavage furrow – indentation where cells will split and separate into two cells Plant Cells cell plate – separates the dividing cell into two cells.

Reviewing metaphase prophase anaphase telophase centrioles spindle fibers anaphase telophase

Cell division Interphase cytokinesis mitosis G1 phase G2 phase S phase prophase metaphase anaphase telophase cytokinesis

_______________ lined up ________________ ________________ attached to chromosomes

v v v v v _____________________________ are pulled apart

_______________________ forming __________________ disappearing