Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
31 Mitosis- Growth, Maintenance, and Repair Biology B Pages 180-188 Name: ___________________ Date: _________ Period: _____________ All organisms (as far as we know) start out as a single celled organism. For our purposes, all cells go through a cycle that includes several basic steps: 1.) a living cell will get larger (that is it usually gets slightly bigger) This part of the cell cycle is called the “G1” phase. See small cell becoming “larger” in pictures to the right 2.) The next phase is the “S” phase, the genetic material duplicates. In humans, we have 23 pairs or 46 chromosomes. During this phase the cell makes a copy of each chromosome (we briefly have 92 chromosomes). Very small piece of the chromosome Condensed chromosome Chromosomes make a copy of themselves: (“S” phase) Page 2 (Cont. #31 Biology B) 3.) The third part of the phase is when the cell is getting ready to split into two cells -all the organelles replicate. This phase is called the “G2” phase. These first 3 steps taken together are often called “Interphase”! 4.) The last part of the cell cycle is the “Mitotic Phase” or the “M” phase. This is where the two sets of DNA are separated and two daughter cells are created from one parent cell. Daughter cells Mitosis is used to: 1.) Repair: repair damaged cells as in cuts, scrapes, blood loss, etc…see cut repair to right. In other words, cell replication or mitosis replaces injured or dead cells with NEW cells. Page 3 (Cont. #31 Biology B) 2.) Maintain: All cells have a life-span (that is how long they live). When they die or start to malfunction, they are replaced by mitosis. 3.) Grow: All organisms start as a single cell (bacterial are only single celled organisms and get a little larger before they divide). Multi-cellular organisms (those that are made up of more than one cell) such as humans start out as a zygote (see picture below) and undergo mitosis MILLIONS of times in an effort to grow a larger organism that is more complex. (The more complex an organism is, the harder it is to kill.) Mitosis can be broken up into six basic stages/phases: Interphase (see pages 1 and 2). 1.) Prophase- the chromosomes condense (become visible using a light microscope) and start to move around 2.) Metaphase- the chromosomes line up in center of cell- in single file 3.) Anaphase- the chromatids separate (move to opposite sides of the cell 4.) Telophase- the chromosomes segregate (each set of chromosomes begin forming walls around themselves- called nuclear membranes) 5.) Cytokinesis- two separate daughter cells form. Page 4 (Cont. #31 Bio. B) Complete the matching here and on scan-tron. Column A Column B _____ 1.) Cell cycle phase where A.) Go organelles replicate _____ 2.) Cell cycle phase where chromosomes replicate B.) G1 _____ 3.) Cell cycle phase where cell grows bigger C.) S _____ 4.) Cell cycle phase where one parent cell becomes two daughter cells D.) G2 E.) M _____ 5.) Cell cycle phase where each daughter cell gets an exact copy of the chromosomes from the parent cell _______________________________________________________ Column A Column B _____ 6.) Mitosis phase where A.) Prophase chromosomes segregate _____ 7.) Mitosis phase where chromosomes move away from each other to opposite sides B.) Metaphase _____ 8.) Mitosis phase where chromosomes line up in single file in the center of the cell C.) Anaphase _____ 9.) Mitosis phase where two separate daughter cells are formed D.) Telophase _____ 10.) Mitosis phase where chromosomes condense and start moving around E.) Cytokinesis Date: _____________________________ Lesson Plant for Handout #31 Biology B Objective: TLWD ability to list and explain the four different parts to the cell cycle and list the five parts of the mitotic cycle when given handout #31. Content: Cell cycle; G1, S, G1=”I”, M…. Mitotic cycle: Prophase, Metaphase, Anaphase, Telophase, and Cytokinesis (PMAT-C) NJCCCS: 5.3.12.A.4 Method: (8 pieces of yarn- two different colors).Yarn pieces as chromosomes given out to all students and walk through the mitotic phases making sure everyone is following along with each step at their desks- I show the movement of the chromosomes on the overhead as I step through phases. Homework: Complete #31 Comments: