Cell Cycle and Mitosis - Cell Division - PDF

Learning Goal: At the end of the lesson, students will be able to understand the cell cycle, mitosis and meiosis, and each phase of cell division. Success criteria: I can describe the phases of the cell cycle. I understand and can describe the difference between mitosis and meiosis. I can describ...

Learning Goal: At the end of the lesson, students will be able to understand the cell cycle, mitosis and meiosis, and each phase of cell division. Success criteria: I can describe the phases of the cell cycle. I understand and can describe the difference between mitosis and meiosis. I can describe the phases of cell division. Instructions: As you go through the slide deck you will watch videos and read scripts that will allow you to understand the cell cycle, mitosis, and meiosis, and each phase of cell division. Complete the Cornell Notes as you proceed through the slide deck.  No matter where you live, you have probably noticed that the weather changes in a regular pattern each year. Some areas have four seasons - winter, spring, summer, and fall. As season change, temperature, precipitation, and the number of hours of sunlight change in a regular cycle. The Cell Cycle Just like the seasons, and the life cycle of plants and animals, cells have a life cycle too.  The Cell Cycle Phases of the Cell Cycle Most cells in an organism go through a cycle The goal of the cell cycle is to create of growth, development, and division called new identical cells the cell cycle. There are two main phases in the cell cycle. The cell cycle makes it possible for organisms ○ To grow and develop These phases are the interphase and ○ To replace cells that are old and the mitotic (mi TAH tihk) phase. damaged, and ○ To produce new cells ○ Mitosis involves the division of body cells  Length of cell cycle Most cells in the human body can complete the cell cycle in about 24 The time it takes a cell to complete hours. the cell cycle depends on the type of cell that is dividing. The cells of some organisms divide The cell cycle for some eukaryotic very quickly. cells might only take eight minutes. For example, the fertilized The cell cycle for other eukaryotic zebrafish divides into 256 cells in cells might take up to one year. 2.5 hours. Phases of the Cell Cycle During Interphase Most cells go through three Interphase is the period of a stages during interphase cell’s growth and development. Three stages of Interphase G1 - Rapid Growth and replication of organelles A cell spends most its life in S - DNA replication interphase. G2 - Preparation for cell division Interphase is then followed by a shorter phase called the mitotic phase (or commonly called mitosis) G1 STAGE The first stage of interphase is the G1 stage. This is a period of rapid growth. G1 is the longest stage of the cell cycle. During this stage the cell grows and carries out normal cell functions. S STAGE The second stage of interphase is the S stage. During this stage, a cell grows and copies its DNA G2 STAGE The third and last stage of interphase is the G2 stage. This is another period of growth and the final preparation for mitosis A cell uses energy to copy DNA during the S stage. During G2, the cell stores energy that will be sued during the mitotic phase of the cell cycle. To understand mitosis, we must first understand that the cell must make a copy of the organelles and DNA before dividing………. Organelle Replication During cell division, the organelles are distributed between the two new cells. Before the cell divides, it makes a copy of each organelle. A cell produces these copies of organelles from materials such as proteins and lipids.  In each of your cells, you have your genetic We organize our DNA into information in the form of DNA. This is located in chromosomes. the nucleus (we learned about the nucleus Chromosomes are made up of when we talked about organelles). DNA and proteins. We have a lot of DNA. Our cells must organize this DNA so it can copy itself and divide into new cells with IDENTICAL DNA in both cells. So we need to organize it. Reading check: What organelle is inside the cell and holds your DNA? We have already covered this information, but if you want you can add more notes to the back of the cornell note worksheet.  What are Generally when you count chromosomes? chromosomes you count how many centromeres (circles in the center) are present. This is a chromosome. This is a chromosome that has been copied. So both of these images are of a chromosome.  Before a body cell divides, the genetic Mitosis material in the nucleus of the cell copies Single itself. When the cell divides, the genetic 46 Stranded material divides in half so that each daughter DNA cell gets genetic material that is the same as DNA replicates the parent cell’s genetic material. The 4646 Double dividing of the nucleus is known as mitosis. stranded DNA There are now 2 complete cells where there DNA divides equally into 2 new cells used to be 1. Single 46 46 stranded Those 46 Two identical daughter cells chromosomes must first be Reading check: If a human body cell has 46 chromosomes, how many chromosomes will be in duplicated. each of the daughter cells?  More on chromosomes! Before the chromosomes can divide, they are duplicated. We still TECHNICALLY have 46 chromosomes, but each has 2 chromatids. These are called sister chromatids. This is still 46 chromosomes! This is a chromosome. Remember we humans start with 46 chromosomes Reading check: How many chromosomes are in a human body cell?  A human body cell contains 46 (that’s 2 sets) chromosomes. This is called the diploid number of chromosomes. One set of 23 chromosomes came originally from your father while the other set of 23 came from your mother. These 46 chromosomes contain all the genetic information to make you, you. As you grow or your body needs repairing, your cells divide. If you think of chromosomes as a way of packaging DNA, then mitosis is a way of making sure that the chromosomes and the DNA they contain are split equally when a cell divides. Knowledge check: What do the chromosomes contain?  Watch this if you still don’t understand chromosomes!!!!!!!!! a t is a ? Wh some o hr om c  To review…. Two identical chromosomes are called sister chromatids. These are made up of a duplicated/replicated chromosome. The sister chromatids are held together by a structure called a centromere. Human body cells have 46 chromosomes that get duplicated before the cell divides. The Mitotic Phase The mitotic phase of the cell cycle follows interphase. There are two stages of mitotic phase: mitosis and cytokinesis.  Cell division occurs in a series of stages or Interphase phases. These steps make sure that the daughter cells are the same as the cell from Prophase which they formed (parent cell). Each stage Mitosis(PMAT) has a name. As a cell prepares to divide, each chromosome in the nucleus makes an Metaphase exact copy of itself. This process is called replication. The two copies are called sister Anaphase chromatids. Telophase and Cytokinesis Reading check: Mitosis makes 2 ___________cells. A.Unique B. Different C. Identical Rewatch this if you need to. Cells multiply by dividing. This process known as mitosis (cell division) allows living things to grow bigger. Cell division also helps living things replace old or injured cells. When one cell divides, it splits into 2 new cells. The 2 new cells are called daughter cells. The goal of mitosis is to create new identical cells Grow Mitosis takes place in body cells. Mitosis makes identical cells! Reading check: The goal of mitosis is? Replace old or injured cells  Prophase - the nucleus is still present and the chromosomes are condensing (becoming visible) First stage is Prophase. “Pro” means “before” The second phase is metaphase. Remember “M” for “middle” During metaphase the nucleus disassembles. Reading check: What becomes visible in Prophase? (see slide 24)  During anaphase, the chromatids separate and begin to move “away” from the middle. The 3rd phase is anaphase. Think “A” for They move to the poles of the cell. “Away” The final phase is Telophase. During telophase two new Think “T” for “two” nuclei begin to form. Remember each new identical nuclei (plural for nucleus) will have 46 chromosomes when we we are referring to humans.  Reading check: When cell division is complete, what has been formed? A. two new sister chromatids B. two new sister cells with different chromosomes C. two new daughter cells with identical chromosomes Then during the last part of mitosis, the cytoplasm of a cell divides creating 2 new identical daughter cells. The Result! Mitosis results in two new cells. These daughter cells are genetically the same. RESULT = two identical daughter cells  Stages of Mitosis Instructions: Drag and drop a description of the key events that are happening at each stage of mitosis. Interphase: e Prophase: e prior to mitosis Metaphase: pindle fibers Anaphase: to 2 daughter cells … we have 2 identical Telophase & Cytokinesis: tids Watch this!!!!!!!!! Mitosis Made Easy What is the difference between mitosis and meiosis? Any questions? Do you have any questions? Something you don’t understand? Remember to DOUBLE-CHECK all your slides to make sure you completed every question. Turn it in!!