Happy Monday 15 Richard investigates whether soaking beans

Happy Monday! – 1/5 Richard investigates whether soaking beans in water before planting affects how the beans grow. Which beans would most likely be the control group? A the beans that were soaked the least amount of time B the beans that were not soaked in water C the beans that had the greatest mass D the beans that grew the tallest

CELL CYCLE Click here to watch brief video over cell cycle

Why do cells divide… A. One-celled organisms § i. ii. for reproduction Asexual reproduction (clones) Binary fission (bacteria only) amoeba B. Multi-celled organisms § for growth & development - from fertilized egg to adult § for repair & replacement - replace cells that die from normal wear & tear or from injury starfish

Happy Tuesday! – 1/6 What structure is shared between all prokaryotes and eukaryotes? A Nucleus B Cell wall C DNA D Mitochondria *****You need to grab 2 colored pencils!*****

Stages of Cell Cycle § The cell cycle is the sequence of growth and division. 1. INTERPHASE: a. G 1 Phase b. S Phase c. G 2 Phase 2. M Phase (MITOSIS)

The Cell Cycle Interphase § The majority of a cells life is spent in Interphase. § Interphase is broken into 3 phases: G 1, S, and G 2 § During Interphase 2 things happen: 1. A cell grows in size. 2. Chromosomes (DNA) are duplicated in preparation for cell division.

3 Phases of Interphase: 1. G 1 Phase (Growth) Ø First growth stage Ø Cell increases in size Ø Cell prepares to copy its DNA

2. Synthesis Phase (S Phase) Ø Copying of all of DNA’s instructions Ø Chromosomes duplicated Ø DNA repairs any errors/damage

3. G 2 Phase (Growth) ØTime between DNA synthesis & mitosis ØCell continues growing ØNeeded proteins produced

Why do cells copy their DNA? § A dividing cell duplicates its DNA creates 2 copies of all DNA u separates the 2 copies to opposite ends of the cell u splits into 2 daughter cells u DNA cell nucleus § But the DNA starts loosely wound in the nucleus § If you tried to divide it like that, it could tangle & break

Organizing & packaging DNA cell nucleus DNA in chromosomes in everyday “working” cell DNA has been “wound up” cell nucleus 4 chromosomes in this organism DNA in chromosomes in cell getting ready to divide

Copying & packaging DNA When cell is ready to divide… 1. 2. copy DNA first, then… coil up doubled chromosomes like thread on a spool… § now can move DNA around cell without having it tangle & break Copying DNA Coil DNA into compact chromosomes

double-stranded human chromosomes ready for mitosis

DNA must be duplicated…before division chromosomes in cell DNA in chromosomes cell nucleus 4 single-stranded chromosomes duplicated chromosomes 4 double-stranded chromosomes cell nucleus

MITOSIS: Making New Cells Making New DNA

5 Stages of MITOSIS: 1. Prophase § DNA is wound up into chromosomes to keep it § § organized Nuclear membrane disappears Centrioles migrate to poles duplicated chromosomes **Different colors of DNA represent what you got from MOM & DAD cell centrioles nucleus

5 Stages of MITOSIS: 2. Metaphase § § chromosomes line up in middle attached to protein “cables” that will help them move M=M Metaphase = Middle duplicated chromosomes lined up in middle of cell

5 Stages of MITOSIS: 3. Anaphase § chromosomes split, separating pairs § start moving to opposite ends A=A Anaphase = Away chromosomes split & move to opposite ends

5 Stages of MITOSIS: 4. Telophase § Cell starts to divide nucleus forms again u Plant cells form CELL PLATES u Animal cells form CLEVAGE FURROWS u

5 Stages of MITOSIS: 5. Cytokinesis § DNA unwinds again § Produces 2 identical daughter cells

***End result of mitosis: TWO identical “daughter” cells § Get 2 exact copies of original cells same DNA u “clones” u Every cell in your body has the same DNA (except sperm & eggs).

Happy Wednesday! – 1/7 One part of the cell cycle controls the repair of damaged DNA which, if unsuccessful, could eventually result in the abnormal cell division that typifies some types of cancer. What phase would repair DNA? A G 1 B S C G 2 D M

Overview of CELL CYCLE interphase prophase I. P. M. A. T. C. prophase Make an acronym to remember the steps: Individual: Please Make Another Two Cells cytokinesis metaphase anaphase telophase

Cell Cycle in Plant Cells Interphase Prophase Metaphase Anaphase Telophase

Cell Cycle

What stage is shown here? Anaphase

And now for the world’s creepiest song about cell division MITOSIS SET TO MUSIC