Name: CP Biology Unit 6: Cell Growth and Development Students will be able to: 6.1 Understand and explain the different aspects of the eukaryotic cell cycle. Explain how cell size is related to cell division Describe the structures involved in cell division including the following: o Chromosomes, centrioles, centromeres, spindle fibers, and nuclear envelope. Describe the phases of the cell cycle o Interphase-Growth 1, Synthesis, G2 (Preparatory for division), Mitosis (stages (PMAT)), Cytokinesis Explain how the cell cycle is regulated o Factors that are involved in the variability of cell division o Apoptosis o Cancer: Explain how losing control of cell division can lead to a disruption in homeostasis o Explain factors that lead to loss of cell cycle regulation 6.2 Compare the generation of gametes (meiosis) to the generation of body cells (mitosis), addressing the following: Stages of Meiosis Compare the purpose, structures, and steps in meiosis and mitosis o Meiosis is used to introduce genetic variation (crossing over, reduction in number of chromosomes) o Mitosis is used for growth, repair, and replacement of cells in a multicellular organism 6.3 Discuss how cells differentiate to fulfill different roles within an organism. Explain how a single celled eukaryotic cell differentiates into the widely varied tissues in the body. Describe the various embryonic tissues in the body and the tissues that arise from them. Discuss how stem cells function in the fully formed body. Biotechnology: How are we using stem cells and other types of signaling molecules to regenerate tissues? Keywords: Daughter Cells Asexual Reproduction Sexual Reproduction Chromosomes Chromatin Homologous Chromosomes Diploid Somatic Cells Haploid Gametes Cell Cycle Chromatid Centromere Mutations Mitosis Cytokinesis Internal Regulatory Proteins External Regulatory Proteins Apoptosis Cancer Meiosis Crossing Over 1
Eukaryotic Cell Growth and Development Unit Date Topic 1/8 Chromosome Notes 1/9 Cell Cycle Notes and Diagram 1/10 Control of the Cell Cycle and Cancer 1/11 The Eukaryotic Cell Cycle and Cancer Animation and Questions 1/14 Vice: Killing Cancer Video 1/15 Mitosis and Cytokinesis Notes and Diagram 1/16 Mitosis Microscope Lab 1/17 Meiosis Notes and Diagram 1/18 Mitosis and Meiosis Model 1/21 NO SCHOOL-Martin Luther King Jr. Day 1/22 Cell Differentiation Reading and Annotations 1/23 Tissue Types Dissection 1/24 Unit Review 1/25 Course Selection Presentation 1/28 Eukaryotic Cell Growth and Development Multiple Choice Test 1/29 Eukaryotic Cell Growth and Development FRQ Test 1/8/19 Objective: Students will be able to describe the structure and function of chromosomes. Warm-Up: 1. What are two things I want you to know by the end of this unit? 2. When is your unit test? 6.1 Chromosomes and Cell Reproduction Why do cells reproduce? 1. 2. 3. Cell Division and Reproduction Growing cells divide to form two o Cell copies DNA prior to dividing Asexual Reproduction: o Examples: Bacteria (binary fission), some fungi, some plants, and even some animals! Sexual Reproduction: Offspring with genetic information from each parent o Examples: 2
There are advantages and disadvantages to each reproductive strategy Chromosomes: Prokaryotic chromosomes (bacteria): No nucleus; DNA molecules found in the cytoplasm. o Most contain a single, circular DNA chromosome Eukaryotic chromosomes (plants and animals): o Chromatin: complex of chromosomes and protein (histones) DNA tightly coils around histones, forming bead-like structures Chromosomes make it possible to separate DNA precisely during cell division After watching the animation, label the following strand and explain the structure at that location. Homologous chromosome: Chromosomes in female parent have corresponding chromosomes in male parent Each carries the same genes in the same order, but by have different alleles for each trait Diploid: Two sets - contain both sets of homologous chromosomes In humans: from mom and from dad for a total of Symbol: Somatic cells: cells that are NOT used in reproduction Haploid: one set - contains only a single set of chromosomes Symbol: Gametes: cells used in reproduction (egg/sperm) 3
1/9/19 Objective: Students will be able to describe the phases of the cell cycle. Warm-Up: 1. If a baseball and a basketball were cells, which would possess a larger surface area to volume ratio? Which cell would be more efficient at getting nutrients and getting rid of waste? 2. How could cell growth create a problem that is similar to a traffic jam? 6.2 The Cell Cycle Cell Cycle: Series of events where a cell grows, prepares to divide, and divides to form two daughter cells Length of the cell cycle, and each part varies depending on the type of cell Cell Cycle Interphase: o Gap 1 (G1): o Synthesis (S): o Chromatid: Each DNA strand in duplicated chromosome (sister chromatids). When the process of mitosis is completed, chromatids will have separated and been divided between new daughter cells. o Centromeres: the part of a chromosome that links sister chromatids o Mutations: a change in a gene due to damage or being copied incorrectly o Gap 2 (G2): o Organelles and molecules needed for division produced o Contain twice as much DNA as the original cell Cell Division o o Mitosis: Cytokinesis: Forms two identical daughter cells 4
Coloring the Cell Cycle Label the diagram below with the following labels: Anaphase Cell division (M phase) Cytokinesis G1- cell grows G2- prepares for mitosis Interphase Interphase Interphase Metaphase Mitosis Prophase S- DNA replication Telophase After labeling the diagram, lightly color the G1 phase of the diagram a chosen color. Highlight the G1 phase in your notes with the same color. Do the same for the G2 phase, stages of mitosis, arrows of interphase, arrow of mitosis, and arrow of cytokinesis. You will use 7 different colors. 1/10/19 Objective: Students will be able to describe how the cell cycle is regulated and the result of disruptions in the cell cycle that leads to uncontrolled cell growth. Warm-Up: (2 Questions) 1. Which side of the diagram, left or right, shows the smallest structures, and which shows the largest? Explain your answer. 5
2. Summarize what happens during interphase. Be sure to include all three parts of interphase. 6.3 Control of the Cell Cycle Not all cells move through the cell cycle at the same rate. Ex: Most nerve cells once they are developed. Ex: Blood cells may complete a cycle. Regulatory Proteins: The cell cycle is controlled by cyclins and other proteins o : Proteins that allow the cell cycle to proceed only when certain events have occurred within the cell. Cyclin: A type of protein that regulates the cell cycle o : Proteins that respond to events outside the cell to speed up or slow down the cell cycle. Growth factors: A type of protein that stimulates growth and division of cells during embryonic development and wound healing. Cell growth and division is controlled by proteins and three checkpoints: 1. : o If the cell is healthy and large enough, it will divide o If conditions are not favorable, it will not divide 2. : o DNA replication is checked by DNA repair enzymes o Once checked, cell will prepare for mitosis 3. : o Triggers the exit of mitosis and the entering of G 1. As new cells are produced, many others must die. This happens in two ways: 1. By accident, due to damage or injuring to a cell 2. Programed to die o : A series of controlled steps leading to the self-destruction of a cell that has been programmed to die. 6
Apoptosis plays a key role in development by shaping the structure of in plants and animals. Ex: The human hand is shaped the way it is because cells between the fingers die by apoptosis during tissue development. Cancer: Caused by defects in the genes Cancer and the Cell Cycle Videos and Questions Video Animation 1 (1:11) Transcript: The rate and timing of cell division in your body are normally very precisely regulated. Cells are formed, mature, and eventually die. As this happens, new cells divide, creating replacement cells. Chemical messengers that pass between neighboring cells help keep the rate of cell division equal to the rate of cell death. Sometimes, a cell breaks free from its normal restraints and begins to follow its own pattern of cell division. This pre-cancerous cell divides more often than normal, eventually producing a mass of cells that also divide more often. Further changes in these cells can increase the frequency of cell division even more until eventually a cancerous tumor develops. At this point, the tumor grows large, but is confined to the tissue where it originated. Late in the development of cancer, some cells may gain the ability to move into blood vessels and travel to other parts of the body. Once established in new locations, these cells continue to divide in an uncontrolled fashion, eventually producing new tumors. 1. What controls the rate of cell division? 2. What is a pre-cancerous cell? 3. What is the cause of a pre-cancerous cell? Video Animation 2 (1:30) Transcript: For many years, it was a mystery to scientists how cells controlled their cell division. Scientists now know that the chemical messages that cells receive from neighboring cells affect a complicated group of molecules in the cell. These molecules are called the "cell cycle clock." The cell cycle clock integrates the mixture of signals the cell receives from its neighbors and determines whether or not the cell should move through each stage of growth and division. If the answer is yes, the cell grows and divides. 7
The cell cycle is composed of four stages. In the G1, or gap one, stage, the cell increases in size and prepares to copy its DNA. Once all the necessary molecules are made, the clock moves the cell to the S phase, called S for synthesis. This is when the cell copies its DNA. After the DNA is copied, a second gap period called G2 occurs, and then the cell divides. The stage in which the cell divides is called M for mitosis. The new daughter cells immediately enter G1. Depending on the signals they receive from neighboring cells, and the decision their cell cycle clocks make, they may go through the cell cycle again or stop cycling temporarily or permanently. Thus, in normal tissues, cell growth and division are precisely controlled by internal clocks. 4. What is the purpose of the Cell cycle clock? 5. Draw a picture of the cell cycle clock: Video Animation 3 (0:40) Transcript: Two types of genes play a major role in regulating the cell cycle. Genes called protooncogenes encourage cell division. Proteins produced by these genes act like accelerators stimulating the cell to grow and divide. In contrast, genes called tumor-suppressor genes inhibit cell division. Proteins produced by these genes act like brakes to slow down or stop cell division. The balance between the activities of proto-oncogenes and tumor-suppressor genes keeps normal cells dividing at a rate that is appropriate for their position and role in the body. 6. Compare and contrast the 2 types of cancer genes Tumor suppressor genes Proto-oncogenes 7. Why is the balance of these 2 genes important? Video Animation 4 (0:59) An important milestone in scientists' efforts to understand cancer came in the 1970s when it was shown that many cancer-causing agents are also able to cause changes in DNA that we call mutations. In fact, 8
research showed that in many cases, chemicals that are powerful cancer-causing agents are also powerful mutagens. Mutagens are agents that produce mutations. This is shown here on a graph that compares the ability of several chemicals to cause cancer with their ability to cause mutations. In contrast, chemicals that have only a weak ability to stimulate the development of cancer were only weak mutagens. We now know that some cancer-causing agents do not fit this simple pattern. But the fact that many cancer-causing agents also cause mutations gave scientists an important clue about what might cause cells to become cancerous. 8. Define carcinogen: 9. Define mutagen: Video Animation 5 (1:18) Normal cell division in the body depends on a precisely regulated set of events that determine when a cell will divide and when it will not divide. Two types of genes called proto-oncogenes and tumorsuppressor genes are primarily responsible for this regulation. When mutated, however, protooncogenes can become what scientists call oncogenes, genes that stimulate excessive division. This situation is similar to getting a car's accelerator stuck in the downward position. A cell that experiences such mutations tends to divide more frequently than it normally would. In contrast, mutated tumorsuppressor genes can become inactive. A cell that experiences a mutation in a tumor-suppressor gene loses some of its crucial braking power. Again, the result is a tendency for the cell to divide more frequently than it normally would. For a cancerous tumor to develop, mutations must occur in several of a cell's division controlling genes. These mutations disturb the balance that normally exists between signals that stimulate cell division and signals that inhibit cell division. The result is uncontrolled division. 10. Explain what causes uncontrolled cell division: 1/11/19 Objective: Students will be able to describe how the cell cycle is regulated and the result of disruptions in the cell cycle that leads to uncontrolled cell growth. Warm-Up: Scientists measured cyclin levels in clam egg cells as the cells went through their first mitotic divisions after fertilization. The data are shown in the graph below. Cyclins are continually produced and destroyed within cells. Cyclin production signals cells to enter mitosis, while cyclin destruction signals cells to stop dividing and enter interphase. 9
1. How long does cyclin production last during a typical cell cycle in fertilized clam eggs? 2. During which part of the cell cycle does cyclin production begin? How quickly is cyclin destroyed? 3. Supposed that the regulators that control cyclin production are no longer produced. What are two possible outcomes? 1/14/19 Objective: Students will be able to describe how the cell cycle is regulated and the result of disruptions in the cell cycle that leads to uncontrolled cell growth. Warm-Up: 1. What are the stages of the cell cycle? Give a summary of what happens in each. 1/15/19 Objective: Students will be able to describe the phases of Mitosis and diagram each phase. Warm-Up: 1. Why do you think it is important that cells have a control system to regulate the timing of cell division? 10
2. How are the growth of a tumor and the repair of a scrape on your knee similar? How are they different? 6.4 Mitosis Mitosis: Division of duplicated chromosomes into two new SOMATIC daughter cells Stages of Mitosis: 1. Prophase: Genetic material inside the nucleus condenses and the duplicated chromosomes become visible. Outside the nucleus, a spindle starts to form. o o Chromatin is compacted into visible chromosomes o o Cell starts to build a spindle (microtubule) that will help separate duplicated chromosomes o 2. Metaphase: Centromeres of duplicated chromosomes line-up across the center of the cell. Spindle fibers connect the centromere of each chromosome to the two poles of the spindle. o Chromosome line up in the middle (equatorial plane) of the cell. o 3. Anaphase: o Anaphase ends when this movement stops and the chromosomes are in two separate groups. 4. Telophase: Chromosomes begin to spread into a tangle of chromatin o Nuclear envelope re-forms around two nuclei o o Nucleolus becomes visible in each daughter nuclei Cytokinesis: Splits one cell into two, completing the process of cell division o Animal cells: cell membrane is drawn inward until pinched in two o Plant cells: cell plate forms halfway between 11
Phases of Mitosis Phase Picture Description Cytokinesis 1/16/19 Objective: Students will be able to identify cells in the various stages of Mitosis. Warm-Up: (2 Questions) 1. If looking at a cell under the microscope, what would you look for at each stage of mitosis to be able to identify what stage that cell is in? 12
2. What do you predict would happen if the spindle fibers were disrupted during metaphase? 1/17/19 Objective: Students will be able to describe the phases of Meiosis and the formation of gametes. Warm-Up: 1. What is cytokinesis and when does it occur? 2. How are cytokinesis and mitosis different? 3. How does cytokinesis differ in animal and plant cells? 6.5 Meiosis Meiosis: Process in which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell. Without meiosis, the number of chromosomes would double in each generation Stages Meiosis I: 1. Prophase I: Each pair of homologous chromosomes pair up o Chromosomes form a tetrad: o Crossing-over: Homologous chromosomes exchange sections of DNA, producing new combinations of alleles. 2. Metaphase I: Paired homologous chromosomes line up on the equator of the cell. 3. Anaphase I: Spindle fibers pull chromosomes toward opposite ends of the cell o 4. Telophase and Cytokinesis: Nuclear membrane forms around each cluster of chromosomes. Cytokinesis follows. o o Neither has a complete set of chromosomes Stages Meiosis II: Prophase II: Chromosomes, consisting of two chromatids, become visible 13
o No tetrads, because they already separated. Metaphase II Cytokinesis: Similar to meiosis I o When two haploid cells combine, they form a zygote: the first cell of a unique individual Phases of Meiosis Meiosis I Meiosis II Prophase I Prophase II Metaphase I Metaphase II Anaphase I Anaphase II 14
Telophase I and Cytokinesis Telophase II and Cytokinesis 1/18/19 Objective: Students will be able to compare and contrast the stages and purpose of Mitosis and Meiosis. Warm-Up: 1. Some cells have several nuclei within their cytoplasm. Considering the events in a typical cell cycle, which phase of the cell cycle is not operating when such cells form? 2. The nerve cells in the human nervous system seldom undergo mitosis. Based on this information, explain why complete recovery from injuries to the nervous system usually does not occur. 1/21/19-NO SCHOOL-Martin Luther King Jr. Day 1/22/19 Objective: Students will be able to explain how cells differentiate to fulfill different roles within an organism. Warm-Up: 1. Explain how two siblings can be very different even though they both get their DNA from the same source (half from mom and half from dad). 15
Cell Differentiation As you read: Box vocabulary words and try to define the words by using clues from the text. Draw a picture of the word. Underline key ideas. Put a question mark next to concepts that don t make sense and you need to look into farther. Vocabulary: Embryo: Picture: 16
Vocabulary: Differentiation: Picture: 17
Vocabulary: Totipotent: Picture: Blastocyst: Picture: Pluripotent: Picture: 18
Vocabulary: Stem Cells: Picture: Vocabulary: Multipotent: Picture: 19
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Benefits of stem cells: Issues related to stem cells: 1/23/19 Objective: Students will be able to explain how cells differentiate to fulfill different roles within an organism. Warm-Up: A scientist performed an experiment to determine the effect of temperature on the length of the cell cycle in onion cells. His data are summarized in the table below. 1. Based on the data in the table, how long would you expect the cell cycle to be at 5⁰? 2. Given this set of data, what is one valid conclusion the scientist could state. 21
1/24/19 Objective: Students will demonstrate their knowledge of the Eukaryotic cell growth and development on a unit review. Warm-Up: 1. Go back to the front page of this packet and read through the essential outcomes. Put a question mark next to the topics that you still have questions about. Put a check mark next to the topics that you feel confident about. 2. How are you going to go about learning those topics that have a question mark next to them? 1/25/19-Course Selection Presentation 1/28/19-1/29/19 Objective: Students will demonstrate their knowledge of the Eukaryotic cell growth and development on a unit exam. Warm-Up: 1. Turn in your homework to the basket. 22