Warm-Up In you warm up section: – How big do you think your cells are? How many cells do you have? – Write a goal for yourself in biology for the remainder of the school year! Read through the calendar to see what’s in store for the next two weeks! *Yeast lab should be finished and in the bin! When you get your results, be prepared to fill them in on your test survey! 1

Unit 6 NOTES: Cell Cycle 6.A- Cell Size Cell Size is limited by… DNA Overload – there is not enough DNA to communicate with the rest of the cell, or organelles, if it gets too big. Material Exchange– there is not enough room for materials (Oxygen, Water, etc) to get into and out of the cell as quickly as needed, if the cell gets too big ! 2 Surface Area and Volume- SA- the area available to the outside, V- the amount of space it takes up. Volume increases faster than surface area, so the cell divides to compensate.

What are new cells used for? 3 Growth Development/Specialization Reproduction Repair/Replace

Forms of a chromosome 6.B NOTES: Cell Cycle 4 DNA is a double helix in shape, but why don’t we see it? It’s so small, so it condenses into chromosomes. Chromosomes are bundled packages of DNA (genetic information). What form the DNA is in, depends on what stage the cell is in during their life cycle.

Chromatin Definition: Long stringy form of DNA “all the double helix is relaxed- uncoiled” Normal form of DNA 5

Chromatid Definition: ½ of a chromosome 6

Sister Chromatids Definition: Two Identical chromatids joined in the center by a centromere. Also called a chromosome. 7

Why aren’t there giant cells? 8

Warm-Up Take out questions 1-9 and Cell Size graphing activity! In your warm-up section: – Why aren’t there giant bacteria cells? – What two things limits cell size? *Be prepared for Quiz 6.A on Cell Size 9

Sequencing With your partner, place the pieces in the most logical order. 10

Centrioles – 11 Only in Animal Cells. (Unit 3) Aid in cell division by growing ‘spindle fibers’ to help move chromosomes.

Phases of the Cell Cycle 12 G1 -growth S -DNA replication G2 -growth -prep for cell division Mitosis- division of nucleus 1.Prophase 2.Metaphase 3.Anaphase 4.Telophase Cytokinesis- Division of cytoplasm

Cell Cycle Phases: INTERPHASE 13 Normal Cell Nucleus not undergoing mitosis yet. DNA is copied (in Chromatin form)

Cell Cycle Phases: PROPHASE 14 The nuclear membrane disintegrates. The chromosomes are floating in the cytoplasm and are composed of two chromatids joined at the centromere. Centrioles have completed their migration to opposite poles.

Cell Cycle Phases: METAPHASE 15 The chromosomes are lined up across the center. Spindle fibers develop and attach to the chromosomes at the centromere.

Cell Cycle Phases: ANAPHASE 16 Chromatids are pulled apart and travel up the spindle fibers. The chromatids are now single stranded chromosomes. The cell membrane starts to pinch the cytoplasm.

Cell Cycle Phases: TELOPHASE 17 Chromosomes uncoil and the nucleus begins to reform. Division of cytoplasm has begun

Cell Cycle Phases: CYTOKINESIS 18 Mitosis and cell division are complete producing two new daughter cells. Normal nuclei are to be seen. IN PLANT CELLS, a cell plate forms. In ANIMAL CELLS, a cleavage furrow forms.

Cell Plate – 19 Only in Plant Cells. The new cell wall forms to divide the two cells. Once it reaches the sides, division is complete.

Cleavage Furrow – 20 Only in Animal cells. Cell Membrane and Cytoplasm pinch in, to divide the cells into two.

Real Pictures of the Cell Cycle ANIMAL CELLS 21

Real Pictures of the Cell Cycle ANIMAL CELLS 22

Real Pictures of the Cell Cycle PLANT CELLS 23

Real Pictures of the Cell Cycle PLANT CELLS 24

At the End of Mitosis… You have 2 new cells (daughter cells) that have the same amount of DNA as the original. So, if a cell has 4 chromosomes, during interphase (when DNA doubles) you would see 8 chromosomes. But by the end of Mitosis, you would have 2 cells, each with 4 chromosomes. 25

Prokaryotes vs. Eukaryotes 26 Bacteria Binary Fission- splits in two DNA= loop/circle Plants, Animals, Fungi, Protists Mitosis DNA= double Helix In Humans= 46 Chromosomes

Prokaryote vs. Eukaryote Bacteria Binary Fission- splits in two DNA= loop/circle Plants, Animals, Fungi, Protists Mitosis DNA= double Helix In Humans= 46 Chromosomes 27 Cell divide by splitting into two

Classwork Mitosis Sequencing Mitosis Cut and Paste 28

Warm-Up Get out your calendar and questions! In your warm-up section, – List the phases of mitosis only. – What stage of the cell cycle occurs before mitosis? Are you prepared for your 5.B Quiz on Mitosis?! 29

Control of the Cell Cycle and Cancer Mutagen- Any thing that can cause a change in your DNA. 30

Control of the Cell Cycle and Cancer Cyclin – A protein that regulates the cell cycle with checkpoints Checkpoints – The cell is checked before being Allowed into the next phase (think of spell check) 31

Control of the Cell Cycle and Cancer 32 Cancer- an uncontrolled growth which could be benign or malignant.