Lesson 1 | The Cell Cycle and Cell Division
Transcription
Lesson 1 | The Cell Cycle and Cell Division
Lesson 1 | The Cell Cycle and Cell Division Student Labs and Activities Page Appropriate For: Launch Lab 8 all students Content Vocabulary ELL 9 all students Lesson Outline ELL 10 all students MiniLab 12 all students Content Practice A 13 AL AL AL Content Practice B 14 AL OL BL Language Arts Support 15 all students Math Skills 17 all students School to Home 18 all students Key Concept Builders 19 Enrichment 23 Challenge 24 AL AL BL Lesson Quiz A 25 AL AL BL Lesson Quiz B 26 AL OL BL AL AL AL all students Assessment Teacher Support Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers (with Lesson Outlines) AL Approaching Level T2 OL On Level BL Beyond Level ELL English-Language Learner Teacher evaluation will determine which activities to use or modify to meet any ELL student’s proficiency level. From a Cell to an Organism 7 Name Date Launch Lab Class LESSON 1: 15 minutes Why isn’t your cell like mine? All living things are made of cells. Some are made of only one cell, while others are made of trillions of cells. Where do all those cells come from? Procedure 1. Read and complete a lab safety form. 2. Ask your team members to face away from you. Draw an animal cell on a sheet of paper. Include as many organelles as you can. 3. Use scissors to cut the cell drawing into equal halves. Fold each sheet of paper in half so the drawing cannot be seen. 5. Have team members sit facing away from each other. Each person should use a glue stick to attach the cell half to a sheet of paper. Then each person should draw the missing cell half. 6. Compare the two new cells to your original cell. 4. Ask your team members to face you. Give each team member half of the cell drawing. Think About This 1. How did the new cells compare to the original cell? Key Concept What are some things that might be done in the early steps to produce two new cells that are more like the original cell? 8 From a Cell to an Organism Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 2. Name Date Class Content Vocabulary LESSON 1 The Cell Cycle and Cell Division Directions: On each line, write the term from the word bank that correctly replaces the underlined words in each sentence. NOTE: You may need to change a term to its plural form. cell cycle centromere cytokinesis daughter cells eukaryotic interphase mitosis sister chromatids 1. At the end of the cell cycle, the division of the cell’s nucleus occurs. 2. Until the sister chromatids in each duplicated chromosome separate during mitosis, they are held together by a special structure. 3. A chromosome is made up of two identical coiled strands of DNA. 4. Following mitosis, the division of the cell’s cytoplasm Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. occurs. 5. Most cells go through a cyclical processe of growth, development, and division. 6. The cell cycle can be divided into two main phases— a period of growth and development and the mitotic phase. 7. Mitosis and cytokinesis result in the formation of two identical new cells. 8. For some cells, identified as those with membrane-bound structures, the cell cycle might take as long as one year. From a Cell to an Organism 9 Name Date Class Lesson Outline LESSON 1 The Cell Cycle and Cell Division A. The Cell Cycle 1. Most cells in an organism go through a cycle of growth, development, and division called the . 2. Because of the cell cycle, organisms grow and , replace old or damaged cells, and produce new cells. B. Phases of the Cell Cycle 1. There are two main phases of the cell cycle—interphase and the 2. phase. is the period of growth and development for a cell. 3. During interphase, most cells go through three stages—rapid growth and of for of the organelles; replication , the genetic information in a cell; and preparation . 4. During the mitotic phase, a cell . 1. makes up most of the cell cycle. 2. During interphase, the DNA in the cell is called . D. Phases of Interphase 1. Interphase begins with a period of rapid growth—the stage. 2. During the stage of interphase, the cell replicates its strands of chromatin. 3. are the two identical strands of DNA that make up the duplicated chromosome. 4. The sister chromatids are held together by a structure called the . 5. The final stage of interphase—the stage—is a period of growth and final preparation for mitosis. 10 From a Cell to an Organism Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. C. Length of a Cell Cycle Lesson Outline continued E. Organelle Replication 1. Before a cell divides, it makes copies of all its . 2. In , the nucleus and its contents divide. 3. In , the cytoplasm and its contents divide. 4. Two new result from mitosis and cytokinesis. F. Phases of Mitosis 1. During , duplicated DNA condenses into chromosomes. 2. During , the chromosomes line up in the middle of the cell. 3. During , sister chromatids in each duplicated chromosome separate and are pulled in opposite directions by the spindle fibers. 4. During , chromosomes begin to uncoil, and two new identical nuclei form. G. Dividing the Cell’s Components 1. After mitosis, usually divides a cell’s cytoplasm, forming a new cell membrane around each daughter cell. 2. In animal cells, a(n) Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. deeper until the cell 3. In plant cells, a(n) in the middle of the cells gets comes together to divide the cell. grows outward toward a new cell wall until two new cells form. H. Results of Cell Division 1. The cell cycle results in two new that are genetically identical to each other and to the original cell, which no longer exists. 2. The cell cycle is important for reproduction in some organisms, growth in organisms, replacement of worn-out or damaged cells, and repair of damaged tissues. From a Cell to an Organism 11 Name Date MiniLab Class LESSON 1: 20 minutes How does mitosis work? The dolix is a mythical animal whose cells contain just two chromosomes. What happens to a dolix cell’s nucleus during mitosis? Procedure 1. Read and complete a lab safety form. 2. Form four 60-cm lengths of yarn into large circles on four separate sheets of paper. Each piece of paper represents one phase of mitosis, and the yarn represents the cell membrane. 3. On each sheet of paper, model one phase of mitosis using different colors of yarn to represent the nuclear membrane, the spindles, and the chromosomes. Use twist ties to represent centromeres. Tape the yarn in place. 4. Label your models, or develop a key to indicate which color is used for which part. Analyze and Conclude 1. Identify If you were to model a dolix cell’s nucleus before mitosis began, what would your model look like? Would you be able to see the individual chromosomes? mitosis? What is this stage? 3. 12 Key Concept During mitosis, the cell forms two new, identical nuclei. Use your models to explain why, in order to do this, mitosis must occur after events in interphase. From a Cell to an Organism Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 2. What would a model of your cell look like during the stage immediately following Name Date Class Content Practice A LESSON 1 The Cell Cycle and Cell Division Directions: On each line, write the term from the word bank that correctly completes each sentence. Each term is used only once. cell cycle centromere cytokinesis interphase mitosis sister chromatids 1. The daughter cells is the regular pattern of growth, development, and division in cells. 2. Identical strands of a chromosome are called 3. Two identical nuclei are formed during 4. Cytoplasm divides to form two cells during . . . 5. The two cells produced during the cell cycle are called . Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 6. After chromatin is duplicated, sister chromatids are connected by a(n) . 7. The two main phases in the cell cycle are and the mitotic phase. Directions: Complete each sentence by circling the correct word(s) in parentheses. 8. The most important result of the cell cycle is two (identical/very different) cells. 9. The cell cycle is important for reproduction in (multicellular/unicellular) organisms. 10. The cell cycle is important for growth and repair in (multicellular/unicellular) organisms. 11. After cell division, the parent cell (divides again/no longer exists). From a Cell to an Organism 13 Name Date Class Content Practice B LESSON 1 The Cell Cycle and Cell Division Directions: Answer each question on the lines provided. 1. What are the two main phases of the cell cycle? 2. During which phase of the cell cycle is chromatin duplicated? 3. During which main phase of the cell cycle do mitosis and cytokinesis occur? 4. What is the difference between mitosis and cytokinesis? 5. What makes up a chromosome? to the parent cell? What happens to the parent cell? 7. How is the cell cycle important to some unicellular organisms? 8. How is the cell cycle important to multicellular organisms? 14 From a Cell to an Organism Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 6. What is produced at the end of the cell cycle? How do they compare to each other and Name Date Class Language Arts Support LESSON 1 Writing Activity: Narrowing a Research Topic Learning the Skill Suppose someone asked you, “What do you know about science?” The question might be too broad for you to answer clearly. If the question were more limited, you would probably have a clearer idea of how to answer the question; for example, “What do you know about how cells reproduce?” The same principle applies when you write a research report. Some topics are broader than others. For example, The Cell Cycle includes everything from the phases of the cell cycle to mitosis. In contrast, The G2 Stage of Interphase is a much narrower topic. You could more easily research and write a brief report on this topic because it covers a limited set of facts. When you choose a topic for a brief research report, make sure it is narrow enough in scope that you can explain it effectively. Use a topic web to break down a broad subject into several subtopics. First, enter your topic in the center of a web such as the one shown below. Then ask yourself questions such as the following: • What different kinds of areas does my topic cover? • What events does it cover? • Which phases does it include? Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. • Which types of cells or organisms does it involve? Use your answers to help you fill in the next group of circles. Circle the subtopic that you find most interesting. Then try to narrow that subtopic by repeating the questions above. DNA replication growth S stage G1 stage G2 stage interphase cell cycle cell cytokinesis mitosis From a Cell to an Organism 15 Name Date Class Language Arts Support LESSON 1 Writing Activity: Narrowing a Research Topic Practicing the Skill Directions: Use the topic web shown on the previous page to answer each question or respond to each statement on the lines provided. 1. With what general topic did the writer begin the web? 2. Name the three subtopics that the writer identified for the cell cycle. Are any of these topics limited enough to cover in a brief research report? Explain your answer. 3. Which of these three subtopics did the writer decide to narrow further? Name the next set of subtopics. Applying the Skill Directions: Review the topic web on the previous page. On another sheet of paper, choose one of the subtopics (e.g., interphase, mitosis, cytokinesis) to use as a starting point to make a web. Narrow it further by adding more circles to your web. Stop when you reach a topic that is narrow enough in scope to cover in a report. Write your topic at the top of a sheet of paper. Then write a brief, one- or two-paragraph report on your research topic. 16 From a Cell to an Organism Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 4. Which topic did the writer finally choose to research? How can you tell? Name Date Math Skills Class LESSON 1 Use Percentages Percentages are used to compare a partial amount to a whole amount. A whole amount is equal to 100%. To convert a ratio or fraction to a percent, multiply by 100. For example, 1 × 100 = 25, so __ 1 = 25%. __ 4 4 Jana got 23 out of 30 points on her quiz. What percentage of the total points did Jana get? Step 1 Identify the ratio and write it as a fraction. The numerator of the ratio represents the partial amount, and the denominator represents the whole amount. 23 ___ 30 Step 2 Divide to change the ratio to a decimal. 23 ___ = 0.767 30 Step 3 Multiply by 100. 0.767 × 100 = 76.7% Jana got 76.7% of the total points. Practice 1. Raj got 51 out of 60 points on his quiz. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. What percentage of the total points did Raj get? 2. Alison has a goal of saving $50. She has saved $31 so far. What percentage of her goal has she saved? From a Cell to an Organism 3. Jesse is reading a book that is 216 pages long. He is on page 88. What percentage of the book has he read? 4. For a certain organism, the interphase stage of the cell cycle takes 42 hours. If the length of the cell cycle is 44 hours, what percentage of the cycle is taken up by interphase? 17 Name Date Class School to Home LESSON 1 The Cell Cycle and Cell Division Directions: Use your textbook to answer each question. 1. Interphase is the time when a cell grows and develops. What are the three stages of interphase? 2. Cells go through two basic phases—interphase and the mitotic phase. How are interphase and the mitotic phase related? What are the two stages of the mitotic phase? 4. When a cell divides, the resulting cells are called daughter cells. What happens to the original cell when it divides into daughter cells? 18 From a Cell to an Organism Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 3. The mitotic phase is the time when a cell divides into two cells. Name Date Class Key Concept Builder LESSON 1 The Cell and Cell Division Key Concept What are the phases of the cell cycle? Directions: Label this diagram by writing the correct term on each line. 1. G1-Rapid growth and replication of organelles 2. Cytokinesis Mitosis S-DNA replication G2-Preparation for cell division Directions: Answer each question on the lines provided. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 3. Which phase of the cell cycle is the period of growth and development? 4. During which phase do the nucleus and cytoplasm divide? 5. How many stages are in each phase of the cell cycle? 6. How does a cell at the end of the first phase of the cell cycle differ from a cell at the end of the second phase? From a Cell to an Organism 19 Name Date Key Concept Builder Class LESSON 1 The Cell and Cell Division Key Concept What are the phases of the cell cycle? Directions: Complete this table by writing a description in each space provided. Phases of the Cell Cycle Phase Interphase Mitotic phase Stage Description G1 1. S 2. G2 3. mitosis 4. cytokinesis 5. 6. What is the DNA in the G1 stage called? What does it look like? 7. During which stage is DNA in the nucleus duplicated? 8. After DNA is duplicated, what is it called? What does it look like? 9. Compare the replication of mitochondria to the replication of organelles that do not have their own DNA. 20 From a Cell to an Organism Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Directions: Answer each question or respond to each statement on the lines provided. Name Date Class Key Concept Builder LESSON 1 The Cell and Cell Division Key Concept What are the phases of the cell cycle? Directions: Mitosis is one stage in the mitotic phase of the cell cycle. Mitosis is divided into four parts. Work with a partner to read each sentence and decide which part of mitosis it describes. On each line, write the term from the word bank that correctly matches each sentence. Terms will be used more than once. anaphase metaphase prophase telophase 1. Duplicated chromosomes align along the middle of the cell. 2. The cell begins to get longer. 3. Duplicated chromatin coils together tightly. 4. Sister chromatids in each duplicated chromosome separate and are pulled in opposite directions by the spindle fibers. 5. The nucleolus disappears, the nuclear membrane breaks down, and spindle fibers form in the cytoplasm. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 6. A nuclear membrane grows around each set of chromosomes. 7. Spindle fibers that helped divide the chromosome begin to disappear, and chromosomes begin to uncoil. 8. Spindle fibers pull and push the duplicated mitotic chromosomes to the middle of the cell. 9. Two new identical nuclei are formed. 10. Two identical sets of chromosomes are at opposite ends of the cell. Directions: Answer each question on the lines provided. 11. What are the two cell division stages in the mitotic phase of the cell cycle? 12. What happens during cytokinesis? From a Cell to an Organism 21 Name Date Key Concept Builder Class LESSON 1 The Cell and Cell Division Key Concept Why is the result of the cell cycle important? Directions: Answer each question or respond to each statement on the lines provided. 1. If a parent cell has 24 chromosomes, how many chromosomes will each daughter cell have? Explain. Then compare the chromosomes in the parent cell and the daughter cells. 2. Explain what kind of organism might use cell division as a form of reproduction. 4. Explain how cell division is important for replacement and repair. Give specific examples. 22 From a Cell to an Organism Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 3. Why is cell division important for a baby? Name Date Class Enrichment LESSON 1 Why do cells divide? Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. A whale is many times bigger than a human. But the cells of whales and humans are nearly the same size. In fact, most cells are small. In plants and animals, most cells are less than 100 micrometers long. You cannot see them without a microscope. Cells are small for a good reason—their small size makes it possible to efficiently take in nutrients and oxygen and to eliminate wastes and carbon dioxide. As you have learned, nutrients and oxygen are transported from the outer cell surface to the inside of the cell. These materials must reach all parts of the cell. As the cell grows, its volume increases faster than its surface area. Eventually, the surface area is not sufficient to handle the large amount of material passing into and out of the cell. Ratio of Volume to Surface Area Let’s look at how the ratio of surface area to volume changes. Consider a cube that is 2 centimeters on each side, as shown in the image. Its surface area is 24 cm2 (height × width × number of sides). Its volume is 8 cm3 (height × length × width). The ratio of surface area to volume is 3:1 (24 cm2 ÷ 8 cm3). If the length of each side of the cube doubles, the surface area is 96 cm2 and the volume is 64 cm3. The ratio of surface area to volume is now 1.5:1. As the length of each side of the cube increases, the ratio of surface area to volume becomes smaller. The volume of the cube increases faster than its surface area. The same trend is true in a cell. As the cell grows, its surface area eventually reaches the point where materials are not efficiently passing into and out of the cell. 2 cm Surface area: 24 cm 2 Volume: 8 cm3 Ratio: 3:1 4 cm Surface area: 96 cm 2 Volume: 64 cm3 Ratio: 1.5:1 Cell Division When a cell’s surface area is too small for its volume, the cell divides or stops functioning. Cell division is the cell’s response to unlimited growth. By maintaining a proper ratio of surface area to volume, the cell ensures that it can interact efficiently with its environment. The small size also means materials do not have to travel far to reach all parts of the cell. Applying Critical-Thinking Skills Directions: Respond to each statement. 1. Solve Imagine a model of a cell shaped like a cube. Calculate the ratio of surface area to volume for a cell model that measures 3 cm on each side. 2. Summarize how cell size relates to cell division. From a Cell to an Organism 23 Name Challenge Date Class LESSON 1 How many are there? Suppose you are observing mitosis in the lab and you want to project how many cells will be produced by a single cell after ten cell cycles. Show your work in the space below. Graph your results. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 24 From a Cell to an Organism