2 2 Cell Cycle Cell cycle- The sequence of stages through which a cell passes between one cell division and the next. (The cycle begin growth and division. )

 The cell spends most of its time in interphase.  Stage 1- G1- cell grows, organelles may begin to duplicate, cytoplasm increases and protein synthesis occurs  Stage 2- S- DNA replicates  Stage 3- G2-cell continues to grow, organelles double, and microtubules synthesize

 Mitosis is a type of cell division that generates two identical daughter cells.  Mitosis occurs in body cells.  Body cells are called somatic cells.

 Mitosis is a part of the cell cycle. It has 4 phases. (PMAT)  Human cells have 46 chromosomes or 23 pairs. This is called a diploid number. (2N)  Mitosis requires only one parent - asexual reproduction.

How do little elephants grow up to be BIG elephants?

Skin cancer - the abnormal growth of skin cells - most often develops on skin exposed to the sun. Cell that reproduce by asexual reproduction reproduce constantly.

Animated Mitosis Cycle Interphase Prophase Metaphase Anaphase Telophase & Cytokinesis

Chromosomes are copied (# doubles) Chromosomes appear as threadlike coils ( chromatin ) at the start, but each chromosome and its copy( sister chromosome) change to sister chromatids at end of this phase CELL MEMBRANE Nucleus Cytoplasm

Animal Cell Plant Cell Photographs from:

Mitosis begins (cell begins to divide) Centrioles (or poles) appear and begin to move to opposite ends of the cell. Spindle fibers form between the poles. Centrioles Sister chromatids Spindle fibers

Animal Cell Plant Cell Photographs from: Spindle fibers

Chromatids (or pairs of chromosomes) attach to the spindle fibers. Centrioles Spindle fibers

Animal Cell Plant Cell Photographs from:

Chromatids (or pairs of chromosomes) separate and begin to move to opposite ends of the cell. Centrioles Spindle fibers

Animal Cell Plant Cell Photographs from:

Two new nuclei form. Chromosomes appear as chromatin (threads rather than rods). Mitosis ends. Nuclei Chromatin

Animal Cell Plant Cell Photographs from:

Cell membrane moves inward to create two daughter cells – each with its own nucleus with identical chromosomes.

Animal Mitosis -- Review Interphase Prophase Metaphase Anaphase Telophase Interphase

Plant Mitosis -- Review Interphase Prophase Metaphase Anaphase Telophase Interphase

I I nterphase P P rophase M M etaphase A A naphase T T elophase C C ytokinesis IPMATC Interesting people meet at the café.

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 1. What is a gene?  2. What are chromosomes?  3. Describe a prokaryotic chromosome.  4. Describe a eukaryotic chromosome.  5. What is chromatin?  6. What is a chromatid?  7. What is a centromere?

 1. Define Cell Cycle What is mitosis?  3. What is cytokinesis?  4. What is a spindle fiber? 

 1. Define Cell Cycle What is mitosis?  3. What is cytokinesis?  4. What is a spindle fiber? 

 Chromatin – uncoiled DNA + proteins (threads)  Chromosome – coiled DNA + proteins (Looks like an X)  Chromatid – only half of a chromosome  Sister chromatids – Two chromatids joined together, by a centromere, to form a chromosome