Happy Tuesday Buffs!! Read Below 1. TURN IN YOUR CODON FACE ASSIGNMENT IF YOU HAVE IT. 2. BELLWORK: WRITE YOUR ANSWER TO THE FOLLOWING QUESTIONS… A. WHAT ARE THE 6 PHASES OF THE CELL CYCLE? B. AT WHAT PHASE DO THE CHROMOSOMES LINE UP? C. DURING WHAT PHASE IS DNA REPLICATED? Happy Tuesday Buffs!! Read Below A. WHAT ARE THE 6 PHASES OF THE CELL CYCLE? INTERPHASE, PROPHASE, METAPHASE, ANAPHASE, TELOPHASE, CYTOKINESIS B. AT WHAT PHASE DO THE CHROMOSOMES LINE UP? METAPHASE C. DURING WHAT PHASE IS DNA REPLICATED? S-PHASE IF YOU HAVE NOT TURNED IN YOUR CODON FACE ASSIGNMENT…. Grades Tests Essential Question: Am I able to identify and analyze phases of the cell cycle? Onion Root Tip Interphase: Nucleus is still visible Most cells are in this phase (G1, S, G2) Interphase: Nucleus is still visible Most cells are in this phase (G1, S, G2) Prophase: Nucleus disappears, Individual chromosomes condense and are visible. Interphase: Nucleus is still visible Most cells are in this phase (G1, S, G2) Prophase: Nucleus disappears, Individual chromosomes condense and are visible. Metaphase: Chromosomes move to center of the cell and line up. Interphase: Nucleus is still visible Most cells are in this phase (G1, S, G2) Prophase: Nucleus disappears, Individual chromosomes condense and are visible. Metaphase: Chromosomes move to center of the cell and line up. Anaphase: Chromosomes move apart to opposite sides of the cell. Interphase: Nucleus is still visible Most cells are in this phase (G1, S, G2) Prophase: Nucleus disappears, Individual chromosomes condense and are visible. Metaphase: Chromosomes move to center of the cell and line up. Anaphase: Chromosomes move apart to opposite sides of the cell. Telophase: Chromosomes regroup and begin to form two NEW nuclei. The cell cycle is an on-going process. The pictures below are “snapshots” of cells at various stages of mitosis. The cells will continue through the process and repeat until they die. Your turn…. Cell Cycle Video... Glue at the top of page 46 CELL CYCLE: series of events that cells go through to grow and divide • The cell cycle is used for the growth and repair of organisms. • Made up of two main sections: Interphase & Mitosis INTERPHASE: • Majority of a cell’s life • Includes 3 phases (G1, S, G2) G1 phase: grow, make proteins, make new organelles Label the G1 phase on your diagram: G1 phase S phase: DNA is replicated; longest part of interphase Label the S phase on your diagram: G1 phase S phase Reminder… WHY does the DNA have to replicate before the cell divides? G2 phase: organelles & proteins required for division are produced When G2 is complete, the cell is ready to divide. Label the G2 phase on your diagram: G1 phase S phase G2 phase Checkpoints: points when the cell checks for problems Sometimes the cell has problems it can’t fix. Problems in the cell cycle can lead to cancer. We’ll talk about that more next week. Label the checkpoints on your diagram: G1 phase ✔ DNA damaged? Cell big enough? All chromosomes aligned? ✔ S phase G2 phase ✔ DNA replicated? Cell big enough? DNA damaged? CELL DIVISION: process where a cell grows and divides into TWO identical daughter cells The last two parts of the cell cycle are M phase (mitosis) and Cytokinesis MITOSIS (M phase): division of the cell’s nucleus *divided into FOUR PHASES: prophase, metaphase, anaphase, and telophase *PMAT* PROPHASE: chromosomes become visible, the centrioles separate to opposite sides of the cell, the chromosomes attach to the spindle, the nucleolus disappears, nuclear envelope breaks down DRAW THIS! The centrioles are two tiny structures located in the cytoplasm that help organize the spindle. The spindle is a fanlike microtubule structure that helps separate the chromosomes. METAPHASE: chromosomes line up along the equator (center) of the cell DRAW THIS! ANAPHASE: the centromeres joining the sister chromatids split; chromosomes move away to opposite sides of the cell, near the poles of the spindle. TELOPHASE: chromosomes begin to disperse; nuclear envelopes reappear to form two new nuclei (nuclei = more than 1 nucleus) Cell division is not complete after telophase! Then comes… CYTOKINESIS: division of the cytoplasm; two identical cells are produced • Fold your paper windowpane style (writing on the inside). • Write Interphase on the left and Mitosis on the right.