Have your body changed in the pass six months? Tall/Weight

Are you taller?

Did your hair grow?

Clip your toenails?

Broken a bone recently?

Wound – how does your body repair itself?

What do the following examples have in common? Scraping your knee and the cut healing. Growing taller. Hair growing continuously if not cut. Finger and toenails growing continuously if not cut. How do these examples relate to the cell theory?

What are the basic parts of the cell theory? All living things are composed of cells. Cells are the basic unit of life. All cells come from pre-existing cells. How do our cells produce new cells? Mitosis

Definition: To create two identical daughter cells that are genetically identical to the parent cells

Q: What kind of cells would perform mitosis? Somatic cells (all body cells except gamete cells) Gamete: sex cell (ex: sperm & egg)

Acronym for MITOSIS IPMAT (C) Interphase Prophase Metaphase Anaphase Telophase (Cytokinesis)

Watch the video on the Cell Cycle and make observations about what you see on your handout using this drawingCell Cycle

I Interphase

Interphase is not part of mitosis It involves creation of new organelles (G 1 ), replication of chromosome (S), and synthesis of proteins necessary for mitosis (G 2 ). Chromosomes appears as thread-like structures called chromatin. Chromosome Count: G1- 23 pairs/ 46 total S – 46 pairs/92 total G2- 46 pairs/ 92 total

P Prophase

Chromatids form (replicated chromosomes condense and become visible in a light microscope) The nucleolus disappears Paired centrioles (centrosomes) move opposite ends of the cell Spindle forms Asters (short microtubules radiating from centrioles) form

A closer view of Chromatids

M Metaphase

Sister chromatids line up at the middle of the spindle (equator) Each centromere attaches itself to the spindle fiber At the end of metaphase, the centromeres divide. Chromosome Count: Beginning- 46 pairs/92 total

A Anaphase

Anaphase Centromere splits and homologus chromosomes go to opposite poles of cell

A Anaphase The separated chromatids, now called chromosomes are pulled apart towards the opposite poles by the contraction of spindle fibres Anaphase is completed when chromosomes arrive at the poles

T Telophase

Chromosomes reach the poles of the cell and cannot be seen clearly The spindle fibers disappear and centrioles replicate Nuclear membrane re-forms around chromosomes and the nucleolus reappears in each nucleus Telophase may lead straight into cytokinesis Chromosome Count: Each new cell has 23 pairs/ 46 total

C Cytokinesis Cytokinesis is the separation of the parent cell’s cytoplasm at the end of a mitosis Cytokinesis in animal and plant cells are different In animal cell: CLEAVAGE FURROW (animal cells) CELL PLATE (plant cells) Chromosome Count: Each new cell has 23 pairs/ 46 total

GROUP ACTIVITY: IDENTIFY THE PHASE OF MITOSIS SHOWN IN THE FOLLOWING SLIDES

Answer: Prophase

Answer: Anaphase

Answer: Interphase

Answer: Telophase/Cytokinesis

Answer: Metaphase

Activity 1: Mitosis in Action Watch the videos on mitosis in animal and plant cells. Answer the following questions after watching: 1.What did you notice about how the chromosomes changes from interphase to prophase? Observe their characteristics. 2.What did you notice happening during metaphase? 3.What did you notice happening to the cell during anaphase? 4.What happened to the cell during telophase/cytokinesis?

Activity 2: Mitosis Chart Make a chart that details the stages of mitosis including interphase, prophase, metaphase, anaphase, and telophase/cytokinesis. Include drawings for each stage. Label key parts of the cell. Include the # of chromosomes present during interphase, anaphase, and telophase/cytokinesis.