What is the cell cycle? Growth And Division

What is Mitosis? Nuclear Division

What is Chromatin? (Thin Chromatin) Stretched out, unwound DNA Looks like spaghetti Not visible under microscope

What is a Chromosome? Coiled up (condensed) version of chromatin; easier for moving DNA (Looks like a slinky)

What is the Centromere? Holds Sister Chromatids together Where spindle fibers grab chromosome (Think: Centro = center mere = middle)

What is the Sister Chromatid? Two identical strands of a chromosome

What are the Centrioles? Organelle that is present only in ANIMAL CELLS and creates the spindle fibers “Centrioles go to the poles”

Name the phases of the Cell Cycle… G1 Phase S Phase G2 Phase M Phase

What happens in the G1 Phase? Growth Phase When cell gets bigger and makes lots of proteins 1st part of Interphase

What happens in the S Phase? “Synthesis” Phase Makes a copy of the DNA Single strand →Double strand 2 nd part of Interphase

What happens in the G2 Phase? “Growth 2” Phase Cell is getting ready to divide Getting organelles and proteins (Like going to grocery store to get the food to prepare dinner) 3 rd part of Interphase

What happens in the M Phase? “Cell Division” Mitosis and Cytokinesis

←Interphase What is the“Cell Growth and Protein Synthesis” stage that is the longest phase of the Cell Cycle? (NOT part of Mitosis) Includes: G1, S, G2

Name the phases of Mitosis (Nuclear division) Prophase Metaphase PMAT Anaphase Telophase

When is the chromatin coiling (visible) under the microscope? (phase) Prophase

Name each phase of Mitosis (not in correct order) Metaphase Telophase Anaphase Prophase

Put each phase of Mitosis in correct order

What happens in Prophase? “Prepare” Longest phase of Mitosis!!! Chromosomes coil up to make easy to move Nuclear envelope (membrane) dissolves Centrioles make spindle fibers Spindle fibers (muscles of chromosome) form to help move Phase #1

“Middle” Chromosomes are lined up in the middle of the cell Spindle fibers are attached and centrioles go to the poles What happens in Metaphase? Phase #2

What happens in Anaphase? “Apart” Chromosomes get pulled apart by spindle fibers Phase #3

What happens in Telophase? “The End” or “Tidy Up” Uncoiling of chromosomes Nuclear envelope reforms Spindle fibers go “bye-bye” Phase #4

Cytokenesis – NOT a phase This is part of Telophase. Hint: cytoplasm gets Kut What is Cell Cytoplasm & Membrane Division called? Actual cell division into two cells dividing into two daughter cells

Cytokenesis in Animal Cells What structure appears? Creates a CLEAVAGE FURROW (Think: Animals have fur)

Cytokenesis in Plant Cells What structure appears? Creates a CELL PLATE (Think: Hard cell wall is like a hard plate)

What are the two new identical cells made in cell division called? 1 cell divides into 2 new cells 2 Daughter Cells

What is it called when a mass of cells are growing out of control? TUMOR

What signals a cell to start the cell cycle?

Why do normal cells stop growing when they touch other cells or reach the sides of a petri dish? Contact with other cells or the sides of the dish signal to the cell to stop growing. This happens when you cut your finger. The cells grow rapidly to fill in the cut. When the cells touch, they go back to normal cell cycle.

What are internal regulators and external regulators? Internal regulators are proteins that respond to events inside the cell to tell it when to go to the next phase of cell cycle. External regulators are proteins that respond to events outside the cell and tell the cell to speed up division then slow down to normal again.

What is it called when cells have lost their ability to control their growth?

Now… Let’s Review Your Mitosis Test Answers