genbio1_mod3_-Cell-Cycle-Mitosis.pdf

General Biology 1 Quarter 3 – Module 3: Cell Cycle: Mitosis General Biology 1 – Grade 11 Alternative Delivery Mode Quarter 3 – Module 3: Cell Cycle: Mitosis First Edition, 2020 Republic Act 8293, section 176 states that: No copyright shall subsist in any work of the Government of the Phili...

General Biology 1 Quarter 3 – Module 3: Cell Cycle: Mitosis General Biology 1 – Grade 11 Alternative Delivery Mode Quarter 3 – Module 3: Cell Cycle: Mitosis First Edition, 2020 Republic Act 8293, section 176 states that: No copyright shall subsist in any work of the Government of the Philippines. However, prior approval of the government agency or office wherein the work is created shall be necessary for exploitation of such work for profit. Such agency or office may, among other things, impose as a condition the payment of royalties. Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names, trademarks, etc.) included in this module are owned by their respective copyright holders. Every effort has been exerted to locate and seek permission to use these materials from their respective copyright owners. The publisher and authors do not represent nor claim ownership over them. Published by the Department of Education Secretary: Leonor Magtolis Briones Undersecretary: Diosdado M. San Antonio SENIOR HS MODULE DEVELOPMENT TEAM Author : Verjel D. Macayan Co-Author – Language Editor : Jocelyn V. Ramirez Co-Author – Content Evaluator : Angelo S. Limboy Co-Author – Illustrator : Ferdianne Antonie B. Bermudo Co-Author – Layout Artist : Melbourne L. Salonga Team Leaders: School Head : Reynaldo B. Visda LRMDS Coordinator : Melbourne L. Salonga SDO-BATAAN MANAGEMENT TEAM: Schools Division Superintendent : Romeo M. Alip, PhD, CESO V OIC- Asst. Schools Division Superintendent : William Roderick R. Fallorin, CESE Chief Education Supervisor, CID : Milagros M. Peñaflor, PhD Education Program Supervisor, LRMDS : Edgar E. Garcia, MITE Education Program Supervisor, AP/ADM : Romeo M. Layug Education Program Supervisor, Senior HS : Danilo S. Caysido Project Development Officer II, LRMDS : Joan T. Briz Division Librarian II, LRMDS : Rosita P. Serrano REGIONAL OFFICE 3 MANAGEMENT TEAM: Regional Director : May B. Eclar, PhD, CESO III Chief Education Supervisor, CLMD : Librada M. Rubio, PhD Education Program Supervisor, LRMS : Ma. Editha R. Caparas, EdD Education Program Supervisor, ADM : Nestor P. Nuesca, EdD Printed in the Philippines by Department of Education – Schools Division of Bataan Office Address: Provincial Capitol Compound, Balanga City, Bataan Telefax: (047) 237-2102 E-mail Address: [email protected] General Biology 1 Quarter 3 – Module 3: Cell Cycle: Mitosis Introductory Message This Self-Learning Module (SLM) is prepared so that you, our dear learners, can continue your studies and learn while at home. Activities, questions, directions, exercises, and discussions are carefully stated for you to understand each lesson. Each SLM is composed of different parts. Each part shall guide you step-by- step as you discover and understand the lesson prepared for you. Pre-tests are provided to measure your prior knowledge on lessons in each SLM. This will tell you if you need to proceed on completing this module or if you need to ask your facilitator or your teacher’s assistance for better understanding of the lesson. At the end of each module, you need to answer the post-test to self-check your learning. Answer keys are provided for each activity and test. We trust that you will be honest in using these. In addition to the material in the main text, Notes to the Teacher are also provided to our facilitators and parents for strategies and reminders on how they can best help you on your home-based learning. Please use this module with care. Do not put unnecessary marks on any part of this SLM. Use a separate sheet of paper in answering the exercises and tests. And read the instructions carefully before performing each task. If you have any questions in using this SLM or any difficulty in answering the tasks in this module, do not hesitate to consult your teacher or facilitator. Thank you. 2  What I Need to Know This module is designed for you to learn about the exciting world of cell preparation and cell formation as part of the cell cycle. You will dwell on and study how cells are formed. You will also explore the distinctions between and among the phases of mitotic cellular division. In this module, you will also have to reflect on the importance of mitosis. At the end of this module, you are expected to: 1. characterize the phases of the cell cycle and their control points (STEM_BIO11/12 – Id – f – 6); 2. describe the stages of mitosis given 2n = 6 (STEM_BIO11/12 – Id – f – 7); 3. explain the significance or applications of mitosis (STEM_BIO11/12 – Id – f – 9); and 4. identify disorders and diseases that result from the malfunction of the cell during the cell cycle (STEM_BIO11/12 – Id – f – 10). 5. What I Know You have already learned the topic about cell cycle, mitosis in particular, during your Grade 8 Science class. Also, you have had enough background about the said topic. To test your prior knowledge about cell cycle and mitosis, the table below is provided for you. All you have to do is to classify the following statements by writing FACT if the statement is true and BLUFF if it is not. After answering the table, browse your module if your answers are accurate. Statement My answer Module’s answer Interphase is the next stage of cell division. Nothing happens in interphase. The cell spends most of its time at rest. Interphase is comprised of smaller phases where growth and synthesis of DNA take place. Cells gain weight first before dividing. There are four phases in mitosis. Read carefully each item. Identify the cell cycle stage described in every concept. Choose the letter of your answer provided below and write it on the line before each number. 3 Cell cycle: Mitosis a. Interphase b. Prophase c. Prometaphase d. Metaphase e. Anaphase f. Telophase _____1. The sister chromatids are moving apart. _____2. The nucleus and other organelles are no longer visible. _____3. A new nuclear membrane is formed around the chromosomes. _____4. The centrioles have reached the opposite poles of the cell. _____5. The threadlike genetic material is formed and found in the nucleus. _____6. The chromosomes are located at the equator of the cell. _____7. The mitotic spindle disappears. _____8. The centromeres of chromosomes split. _____9. The mitotic spindle is formed. _____10. The cell actively produces protein. _____11. The cell elongates. _____12. Centrioles start to move toward the opposite poles of the cell. _____13. Cytoplasmic contents start to duplicate. _____14. The reverse of prophase. _____15. The mitotic spindles converge and connect to the kinetochore of chromosomes. Lesson 1 Cell Cycle: Mitosis The ability to reproduce in kind is a basic characteristic of all living organisms. “In kind” means that the offspring of any organism closely resemble their parent or parents. Sexual reproduction requires fertilization, the union of gametes from two individual organisms resulting in a fertilized egg or zygote. Countless cell divisions subsequently occur in a controlled manner to produce a complex, multicellular organism. In other words, that original single cell is the ancestor of every other cell in the body. Once an individual is fully grown, cell reproduction is still necessary to repair or regenerate tissues. For example, new blood and skin cells are constantly being produced. All multicellular organisms use cell division for growth and for the 4 maintenance and repair of cells and tissues. For single – celled organisms, they use cell division as their method of reproduction. The continuity of life from one cell to another has its foundation in the reproduction of cells by way of the cell cycle. The cell cycle is an orderly sequence of events that describes the stages of a cell’s life from the division of a single parent cell to the production of two new daughter cells. The mechanisms involved in the cell cycle are highly regulated. Mitosis is the part of a cell cycle that results in identical daughter nuclei that are also genetically identical to the original parent nucleus. In mitosis, both the parent and the daughter nuclei are at the same ploidy level – diploid for most plants and animals. Meiosis employs many of the same mechanisms as mitosis. However, the starting nucleus is always diploid and the nuclei that result at the end of a meiotic cell division are haploid. Nuclear division (karyokinesis) is usually followed by the cytoplasm into two (cytokinesis). What’s In Let us first have a short recap of the applications of cell cycle and mitosis so you can better understand the significance of mitotic cell division. Below are pictures which can lead you to enumerate the importance of cell cycle and mitosis. You need to interpret each picture and so, you can state the significance of mitotic cell division. Image source: Wikimedia Commons File name: File:Human Development-Male.jpg 5  What’s New Has anyone ever told you that you were “going through a phase”? A phase is a defined period within a cycle of change. Cells go through phases, too. The sequence of phases in the life cycle of a cell is called the cell cycle. The cell cycle has two parts: Growth and preparation (interphase) and cell division (mitosis or meiosis). Cell division in turn is divided into two stages: Karyokinesis and cytokinesis. Below is an activity that will help you understand the phases of cell cycle. The figure below shows the amount of time spent by a typical cell in each phase of the cell cycle. After observing the table, answer the given questions. Image source: Biology LibreTexts File name: The Cell Cycle.jpeg a. Which phase of cell cycle is the longest? b. Which is the shortest? c. What do you think is happening to the chromosomes when the cell is at the end of G2 phase prior to mitosis? What is It It has already said that cell cycle has two major parts: Interphase and cell division. This module will be focusing on mitosis that involves the cell division of body cells (somatic). During interphase, the cell grows and DNA is replicated. During the mitotic phase, the replicated DNA and cytoplasmic contents are distributed, and the cell divides to produce two identical daughter cells. 6  How does the cell prepare for mitosis while in interphase? Interphase is the part of the cell cycle through which the cell undergoes normal growth processes while also preparing for cell division. In order for a cell to move from interphase into mitotic phase, many internal and external conditions must be met. Interphase is by far the longest part of the cell cycle – typically about 90 percent of the total time. Interphase has three stages based on the metabolic activity taking place in the cell: G1 (first gap), S (synthesis stage), and G2 (second gap). The phases of cell cycle happen along with the cell cycle control system. Cell cycle control system, also called as cell cycle checkpoints, is driven by a built-in clock that can be adjusted by external stimuli like sending chemical messages (protein). This control system is essential to ensure that the daughter cells produced be exact duplicates of the parent cell. Mistakes in the duplication or distribution of the chromosomes lead to mutations that may be passed on to every new cell produced from as abnormal cell. Cell cycle control system has three main checkpoints: G1 checkpoint, G2 checkpoint, and metaphase checkpoint. G1 checkpoint is the restriction point which ensures that the cell is large enough to divide and that enough nutrients are available to support the resulting daughter cells. If the said requirements were met, the cell will receive a “go – ahead” signal from a protein called kinase, allowing the cell to enter the cell cycle. If the cell doesn’t receive a “go – ahead” signal, it will exit the cell cycle and switch to a non – dividing state called G0 (quiescent phase). First Gap (G1) During G1, the cell actively produces ATP, RNA, and protein. Also, during this stage, the cell increases in size. Synthesis Stage (S) During the S stage, the chromosomes, specifically their DNA, replicate. As DNA replication has ended, the cell enters another checkpoint called the G2 checkpoint. This checkpoint ensures that DNA replication in S phase has been successfully completed. If the said requirement was met, the cell will receive a “go – ahead” signal from kinase, allowing the cell to enter the second gap (G 2). Second Gap (G2) During G2, the cell organelles duplicates. Also, the chromosomes uncoil to form the chromatin materials which will then turn into granules. Chromatin materials are threadlike form of chromosomes. 7 Thought – Provoking Question 1: A researcher treats cells with a chemical that prevents DNA synthesis from starting. This treatment would trap the cells in which part of the cell cycle? What are the phases of mitosis? Prophase As the cell exits the second gap, the cell will now proceed to mitosis. During prophase, the first part of mitosis, the chromatin materials start to condense, forming discrete chromosomes. The nucleus and other organelles of the cell start to disintegrate. Centrioles start to move toward the opposite pole of the cell along with the radiation of mitotic spindle between them. Prometaphase During prometaphase, a transition phase between prophase and metaphase, chromatin materials have coiled to form the chromosomes. The nucleus and other organelles are no longer visible. The centrioles have reached the opposite poles of the cell. Spindle fibers converge and connect to the kinetochore of chromosomes. As the interconnection of spindle fibers to the chromosomes, specifically to their kinetochore, has ended, the cell enters the metaphase checkpoint. This checkpoint ensures that all of the chromosomes are attached to the spindle fibers by their kinetochore. If the said requirement was met, the chromosomes will force to move toward the center of the cell. Metaphase During metaphase, the chromosomes convene on the metaphase plate, an imaginary plane equidistant between the two poles of the spindle fibers. Anaphase Anaphase begins when the centromere of each chromosome come apart, separating the sister chromatids. Spindle fibers will then pull the chromatids toward the opposite poles of the cell. Along with that action is the formation of spindle fibers between the migrating chromatids which causes the cell to elongate. 8 Telophase Telophase is roughly the reverse of prophase. The cell elongation that started in anaphase continues until a constriction is formed from the outer middle portion of the cell. The chromosomes have reached the opposite poles of the cell. The spindle fibers start to disappear. Nuclei and cytoplasmic contents of the daughter cells start to reform. The chromosomes start to decondense. Cytokinesis During cytokinesis, in some references is referred to as the late telophase, the nuclei and cytoplasmic contents of the daughter cells are fully visible. The chromosomes are no longer visible. The constriction continues forming the cleavage furrow, which pinches the cell in two. Two new daughter cells are formed, each with a complete set of chromosomes as the parent cell. Thought – Provoking Question 2: Red blood cells, which carry oxygen to body tissues, live for only about 120 days. Replacement cells are produced by cell division in bone marrow. How many cell divisions must occur each second in your bone marrow just to replace red blood cells? Here is the information to use in calculating your answer: There are about 5 million red blood cells per cubic millimetre (mm3) of blood. An average adult has about 5 L (5,000 cm3) of blood. (Hint: What is the total number of red blood cells in the body? What fraction of them must be replaced each day if all are replaced in 120 days? How can mutations lead to changes in the cell cycle? Cell growth is carefully controlled in multicellular organisms. Cells in some parts of your body may rarely divide or actively divide. During the healing process of wounds, cells divide actively. Toward completion of healing, cell division slows down, the growth is controlled, and everything returns to normal when the healing is done. At times, errors happen along with cell growth. These errors can be caused by toxic compounds, radiation, or viruses. Due to these errors, the mitotic process can be disrupted, resulting to mutations. Mutations cause a permanent error, or change, in the genetic material of a normal cell. The table on the next page shows some errors in mitosis. 9  Errors in Mitosis Error in Cell cycle cell events Characteristic properties division affected Cancer Interphase The cell produces incorrect DNA copies. As a result, mutated cells are formed known as cancer cells. Cancer cells do not respond normally to the cell cycle control system; they divide actively producing an abnormally growing mass of body cells called tumor. Benign tumor is a lump of cancer cells that remain at the original site Malignant tumor is a lump of cancer cells that can spread into neighboring tissues and other parts of the body, displacing normal tissue and interrupting organ function as it goes. This spread of cancer cells via the circulatory system beyond their original site is called metastasis. Non – Anaphase The chromosomes or sister chromatids failed to separate disjuncti that may to chromosomal mutation. on Mosaicism is a condition where some cells in an individual have a mutant version of a gene while other cells have a normal version of the same gene. It usually results from non – disjunction of sister chromatids during fetal development. Two examples of diseases linked to mosaicism are hemophilia, a blood – clotting disorder, and Marfan syndrome, or unusually long limbs. What’s More Use the table below to answer the questions about mitosis. Growth Rate of Rapidly Dividing Human Liver Cell Time (hours) Number of cells 0 1 10 2 20 4 30 8 40 16 50 32 a. Assuming that no cells die, how many cells will there be in one week? b. Assuming that the original cell is diploid and divides mitotically, how many copies of each chromosome will there be in 60 hours? 10  What I Have Learned Now it’s your turn! In the light micrograph of dividing cells near the tip of an onion root given on the next page, identify the cell/s that is/are in interphase, prophase, prometaphase, metaphase, anaphase, and telophase. Describe the major events occurring at each stage. Image source: Wikimedia Commons File name: File:Mitosis (261 15) Pressed; root meristem of onion.jpg What I Can Do HeLa cell is an immortal cell line used in scientific research. It is the oldest and most commonly used human cell line. The line was derived from cervical cancer cells taken on February 8, 1951 from Henrietta Lacks, a 31 – year – old African – American mother of five, who died of cancer on October 4, 1951. The cell line was found to be remarkably durable and prolific, which causes it to be used extensively in scientific study. The cells from Lacks’ cancerous cervical tumor were taken without her knowledge or consent, which was common practice at the time. There was no requirement at that time (or at present) to inform patients or their relatives about such matters because discarded material or material obtained during surgery, diagnosis, or therapy was the property of the physician or the medical institution. The cells were propagated by George Otto Gey shortly before Lacks died of her cancer in 1951. This was the first human cell line to prove successful in vitro, which was a scientific achievement with profound future benefit to medical research. The cells were freely donated by Gey but later commercialized, although never patented in their original form. 11 Lacks’ case is one of many examples of the lack of informed consent in 20 th century medicine. Communication between tissue donors and doctors was virtually nonexistent. Lacks’ family also had no access to her patient files and had no say in who received HeLa cells or what they would be used for. Additionally, as HeLa cells were popularized and used more frequently throughout the scientific community, Lacks’ relatives received no financial benefit and continued to live with limited access to healthcare. This issue of who owns tissue samples taken for research was brought up in the Supreme Court of California. The court ruled that a person’s discarded tissue and cells are not his or her property and can be commercialized In your point of view as a senior high school STEM student, do you think the Henrietta Lacks’ relatives were treated fairly? Is there anything else you would like to know about this case that might help you decide? Explain your answer using the concepts that you have learned from this module. Assessment Let’s see how well you have enjoyed the amazing world of cell cycle and mitosis by answering the following questions. Choose and encircle the letter of the best answer. _____1. Chromosomes are duplicated during what stage of the cell cycle? a. G1 phase c. Prophase b. S phase d. Prometaphase _____2. Which of the following events DOES NOT occur during some stages of interphase? a. DNA duplication c. Increase in cell size b. Organelle duplication d. Separation of sister chromatids _____3. In which cell structure do mitotic spindles arise from? a. Centromere c. Kinetochore b. Centrosome d. Cleavage furrow _____4. Which stage of mitosis is characterized by the attachment of mitotic spindle fibers to kinetochores? a. Prophase c. Metaphase b. Prometaphase d. Anaphase _____5. During which stage of mitosis do unpacking of chromosomes and the formation of a new nuclear envelope happen? a. Prometaphase c. Anaphase b. Metaphase d. Telophase 12 References Belardo, Gisselle Millete M., et al. (2016). General Biology 1. Quezon City, Philippines: Vibal Group, Inc. Pp. 104 – 139. Calsado, Chuckie Fer, et al. (2016). Teaching Guide for Senior High School: General Biology 1. Quezon City, Philippines: Commission on Higher Education. Pp. 36 – 44. Campbell, Neil A., et al. (2009). Biology: Concepts and Connections. Sixth Edition. Jurong, Singapore: Pearson Education Asia Pte Ltd. Pp. 125 - 151. Capco, Carmelita M., et al. (2000). Biology. Second Edition. Quezon City, Philippines: Phoenix Publishing House, Inc. Pp. 231 – 239. Hadsall, Annalee S., et al. (2008). Exploring Science and Technology: Biology. Makati City, Philippines: DIWA Scholastic Press, Inc. Pp. 251 – 259. Strauss, Eric, et al. (2003). Biology: The Web of Life. Second Edition. Jurong, Singapore: Pearson Education Asia Pte Ltd. Pp. 102 – 123. Biology LibreTexts. 6.2: The Cell Cycle.jpeg. Image/jpeg. August 15, 2020. https://bio.libretexts.org/@api/deki/files/9319/Figure_06_02_01.jpg?r evision=1&size=bestfit&width=800&height=561 Wikimedia Commons. File:Human Development-Male.jpg. Image/jpeg. March 1, 2017. https://upload.wikimedia.org/wikipedia/commons/e/eb/Human_Deve lopment-Male.jpg Wikimedia Commons. File:Mitosis (261 15) Pressed; root meristem of onion.jpg. image/jpeg. March 11, 2014. https://upload.wikimedia.org/wikipedia/commons/1/15/Mitosis_%28 261_15%29_Pressed%3B_root_meristem_of_onion.jpg 13 For inquiries or feedback, please write or call: Department of Education – Region III, Schools Division of Bataan - Curriculum Implementation Division Learning Resources Management and Development Section (LRMDS) Provincial Capitol Compound, Balanga City, Bataan Telefax: (047) 237-2102 Email Address: [email protected]