...DISCUSSION 2.1 Phases And Events Of The Cell Cycle 2.1.1 Phases And Subphases Generally, there are two phases in cell cycle. Those are interphase and mitotic phase. Figure 1.0: The cell cycle Interphase consist of G1, S, and G2. The name of G actually represent as “gap” while S represent as “synthesis”. So, the name for G1 is also known as “first gap”, S is “synthesis”, and G2 is “second gap”. There is a reason why it is called “gap”. It is because, when the cells were observed long time ago, it appeared as inactive which in inactive period, it create a gap between S phase and mitotic phase. However, as the world hurtles down the path of fast scientific development, we now know that there is a growth and metabolic activity inside cells. The mitotic phase is divided into two, mitosis and cytokinesis. Mitosis consist of prophase, prometaphase, metaphase, telophase, and anaphase. 2.1.2 Duration Of Cell Cycle Approximately, G1 takes about 5 – 6 hours, S takes about 10 – 12 hours, and G2 takes about 4 – 6 hours. Mitotic phase takes less than 1 hour. Overall, a normal human cells take about 24 hours to complete a cell cycle. 2.1.3 Events In The Cell Cycle In each subphases, several events occurred in well ordered. Starting from G1, the growth of cells occurred in this phase by producing proteins and cytoplasmic organelles. Until at the end of G1, the enzymes required for DNA synthesis become more active. The process continue with S phase, in this entire phase, the chromosome...
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...THE CELL CYCLE WORKSHEET Name: Catherine Dauw Date: 3 Novmeber 2015 Per: A A) The diagram below shows six cells in various phases of the cell cycle. Note the cells are not arranged in the order in which the cell cycle occurs. Use the diagram to answer questions 1-11. M Phase 1. Cells A & F show an early and a late stage of the same phase of the cell cycle. What phase is it? C 2. Which cell is in metaphase? A 3. Which cell is in the first phase of M phase (mitosis)? D (interphase), A (prophase), F (prophase), C (metaphase), E (anaphase), and B (telephase) 4. List the diagrams in order from first to last in the cell cycle. 5. In cell A, what structure is labeled X? spindle fibers 6. Are the cells depicted...
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...N Driving the Cell Cycle Through Metabolism Ling Cai and Benjamin P. Tu Annu. Rev. Cell Dev. Biol. 2012.28. Downloaded from www.annualreviews.org by Ecole Polytechnique Federal Lausanne on 06/20/12. For personal use only. Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9038; email: benjamin.tu@utsouthwestern.edu Annu. Rev. Cell Dev. Biol. 2012. 28:3.1–3.29 The Annual Review of Cell and Developmental Biology is online at cellbio.annualreviews.org This article’s doi: 10.1146/annurev-cellbio-092910-154010 Copyright c 2012 by Annual Reviews. All rights reserved 1081-0706/12/1110-0001$20.00 Keywords cell growth, cell proliferation, metabolic cycle, growth control, nutrients, yeast Abstract For unicellular organisms, the decision to enter the cell cycle can be viewed most fundamentally as a metabolic problem. A cell must assess its nutritional and metabolic status to ensure it can synthesize sufficient biomass to produce a new daughter cell. The cell must then direct the appropriate metabolic outputs to ensure completion of the division process. Herein, we discuss the changes in metabolism that accompany entry to, and exit from, the cell cycle for the unicellular eukaryote Saccharomyces cerevisiae. Studies of budding yeast under continuous, slow-growth conditions have provided insights into the essence of these metabolic changes at unprecedented temporal resolution. Some of these mechanisms by which cell growth and proliferation...
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...10th 2011 The Cell Cycle Directions: Answer the following questions. Cite references as needed. Be sure to read the required Module 3 readings and view the required Web sites before completing the assignment. Cell Cycle Questions for Cell Cycle 1) . Briefly describe all phases of the cell cycle and tell what happens in each. a) Interphase: G1 phase, S phase, G2 phase Interphase: Before a cell can enter cell division, it needs to take in nutrients. All of the preparations are done during the interphase. Interphase proceeds in three stages, G1 phase, S phase, G2 phase. Cell division operates in a cycle. Therefore, interphase is preceded by previous cycle mitosis and cytokinesis (Module 3 Readings). a. G1 phase: The cell increases the supply of proteins and increases its organelles. b. S phase: Linear chromosome is replicated. c. G2 phase: Increases protein preparing to replicate. (Module 3 Readings) b) M phase: M phase is a method of indirect cell division by means of which the two daughter nuclei normally receive identical complements of the number of chromosomes of the somatic cells of the species. 2) Which phase is the shortest? Anaphase is the shortest phase of mitosis because its where the chromatids twins are all pulled apart at the centromere by the spindle fibers. 3) What is G0 (Gap 0/Resting phase)? A resting phase is when or where the cell has left the cycle and has stopped dividing. 4) If a cell never entered the...
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...Kaitlyn Hainline Biology-4 The Cell Cycle Lab I. Design A. Problem/Research Questions 1. What is the relative time it takes for a cell to go through each phase? B. Variables 1. Independent Variable- The independent variable is the different cell phases (Interphase, Prophase, Anaphase, and Telophase/Cytokinesis). 2. Dependent Variable-The dependent variable is the percentage of cells that are each cell phase. C. Controlled Factors- The magnification is a control factor because I was able to decide what magnification the microscope was on and mine was at (400x). Another control factor was the temperature because it stayed at room temperature throughout the whole experiment. D. Apparatus/Materials Needed * 2 pre stained onion root slides * A microscope at 400x magnification * Calculator * writing utensil * paper E. Procedure 1. Observe every cell in one high-power field of view and determine which phase of the cell cycle the cell is in. 2. Count at least two full fields of view. If you have not counted at least 200 cells, then count a third field of view. 3. Record, process and present your data. II. Data Collection and Processing A. Data Collection 1. Mass of | Number of cells in each phase + 1cell | Percent of cells in each phase (%) | Time spent in each phase (hours) | 2 slides tested | Slide 1 | Slide 2 | Slide 1 | Slide 2 | Slide 1 | Slide 2 | Interphase | 75 | 215 | 32% | 77% |...
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...University of Phoenix Material Comparing Cell Cycles Complete the Cell Cycle charts below. Describe the events in each phase for Cell Cycle A. Compare the steps in mitosis and meiosis for Cell Cycle B. Cell Cycle A |Phase |Describe the events in each phase | |G1 (1st growth stage) |This is the portion of the cell cycle just after division, but before DNA synthesis. During this| | |time the cell grows by producing proteins and organelles. | |S (Synthesis) |DNA synthesis (or replication) occurs during this phase. At the beginning of the phase, each | | |chromosome is single. At the end, after DNA replication, each chromosome consists of two sister | | |chromatids | |G2 (2nd growth stage) |This third subphase of interphase is a period of metabolic activity and growth. During this | | |phase the cell makes final preparations for division. | |Prophase of mitosis |Prophase occupies over half of mitosis. The nuclear membrane breaks down to form a number...
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...the cell cycle, including the steps of Interphase. G1 phase - growth and synthesis. Gap phase 1 begins at the completion of mitosis and cytokinesis and lasts until the beginning of S phase. This phase is generally the longest of the four cell cycle phases and is quite variable in length. During this phase, the cell chooses either to replicate its deoxyribonucleic acid (DNA) or to exit the cell cycle and enter a quiescent state (the G0 phase). S phase Replication of the chromosomes is restricted to one specific portion of interphase, called S phase (DNA synthesis phase), which typically lasts about 6 h. In mammalian cells, the start of S phase—the actual initiation of DNA synthesis—takes place several hours after the cell has committed to carrying out DNA synthesis. During S phase, each chromosome replicates exactly once to form a pair of physically linked sister chromatids. In animal cells, a pair of centrioles is also duplicated during S phase. G2 phase - Preparation for division The portion of interphase that follows S phase is called gap phase 2. Some cells can exit the cell cycle from G2 phase, just as they can from G1 phase. M phase M phase includes the overlapping processes of mitosis and cytokinesis. Mitosis is divided into five stages: prophase, prometaphase, metaphase, anaphase, and telophase. Cytokinesis usually begins during anaphase and ends at a point after the completion of mitosis. At the end of cytokinesis, the parent cell has...
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...7. Uterine (Menstrual Cycle) The Uterine cycle of menstruation starts from the first day of the menstrual period, which is also the first day of bleeding. It can be divided into three distinct phases. 1. The Menstrual Phase This phase is also called the 'bleeding phase' or the 'menstrual period'. It usually lasts from the 1st to the 5th day of the cycle. The duration of bleeding can vary from 2 days to 7 days in different women. Usually the flow is less on the first day, increases during the 2nd and the 3rd day and peters off on the 4th and 5th days. The menstrual discharge or the bleeding during he period consists of dead endometrial cells, blood, vaginal cells, mucous from the cervix and other necrotic tissue. The main cause for the occurrence of menstruation is the withdrawal of the ovarian hormones - oestrogen and progesterone - due to the degeneration of the corpus luteum in the ovaries at the end of the ovarian cycle. The lack of hormones causes the endometrium to shrink. The blood vessels of this region become highly coiled on themselves and the blood stagnates in these coils. The endometrial cells get necrosed due to unavailability of blood. The endometrial tissue soon dies off and passes out of the uterus and vagina as menstrual bleeding. 2. The Proliferative Phase Once the menstrual bleeding stops there is a short duration of about 48 hours when the endometrium rests and repairs itself ('resting phase'). At this time, the endometrium is disorganized and chaotic...
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...morphologically, producing black perithecia containing asci with eight dark ascospores in a linear arrangement. These species share a number of characteristics that are advantageous for genetic studies. They all have a short life cycle, usually 7–12 days, and are easily grown in culture. Most species are self-fertile and each strain is isogenic. All kinds of mutants are easily induced and readily obtainable with particular ascospore color mutants. These visual mutants aid in tetrad analysis, especially in analysis of intragenic recombination Eukaryotic cell cycle The division cycle of most cells consists of four coordinated processes: cell growth, DNA replication, distribution of the duplicated chromosomes to daughter cells, and cell division. In bacteria, cell growth and DNA replication take place throughout most of the cell cycle, and duplicated chromosomes are distributed to daughter cells in association with the plasma membrane. In eukaryotes, however, the cell cycle is more complex and consists of four discrete phases. Although cell growth is usually a continuous process, DNA is synthesized during only one phase of the cell cycle, and the replicated chromosomes are then distributed to daughter nuclei by a complex series of events preceding cell division....
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...THEY AFFECT ITS ROLE IN THE CELL CYCLE P53 plays a very important role in controlling the cell cycle. Defective p53 can cause multiplication of abnormal cells, which leads to cancer. Over 50% of human tumours contain p53 mutants. Damaged DNA and some stress signals can activate the increase of p53 proteins while normally; the p53 protein level is available in lower quantities. To reduce the damaged DNA, p53 can repair DNA; it can perform growth arrest and initiate apoptosis (cell death). Description of p53 p53, which is also known as TP53 or a tumour protein, has its locus on the chromosome 17p13.1 and codes for a protein. The p53 protein is responsible for tumour suppression: it stops the formation or growth of cancerous...
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...Chapter 12: The Cell Cycle Reading guide Overview: 1. What are the three key roles of cell division? State each role, and give an example. 2. What is meant by the cell cycle? Concept 12.1 Cell division results in genetically identical daughter cells 3. What is the meaning of genome? Compare your genome to that of a prokaryotic cell. 4. How many chromosomes are in a human somatic cell? 5. Name two types of somatic cells in your body. 6. What is a gamete? 7. Name the two types of gametes. 8. How many chromosomes in a human gamete? 9. Define chromatin. You are going to have to learn the difference between a number of similar-sounding terms. The sketch that looks like an X represents a replicated chromosome that has two sister chromatids. The narrow “waist” represents the location of the centromere. Students often get all these terms confused, so take time now to label the indicated areas of the figure and then define each of the terms below. chromosome chromatid centromere chromatin 13. What is mitosis? How is it different from cytokinesis? 14. What occurs in meiosis? How is the chromosome number of daughter cells different? 15. Select either mitosis or meiosis to answer the following questions. ___________________ By what process are the damaged cells in a wound replaced? ___________________ By what process are eggs formed? ___________________ By what process does a zygote develop into a multicellular organism...
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...Chapter 8 The Cellular Basis of Reproduction and Inheritance Multiple-Choice Questions 1) The creation of offspring carrying genetic information from a single parent is called A) asexual reproduction. B) sexual reproduction. C) a life cycle. D) regeneration. E) spontaneous generation. Answer: A 2) Which of the following statements regarding sexual and asexual reproduction is true? A) Cell division only occurs after sexual reproduction. B) Only offspring from asexual reproduction inherit traits from two parents. C) Sexual reproduction typically includes the development of unfertilized eggs. D) Sexual reproduction is more likely to increase genetic variation than is asexual reproduction. E) Only asexual reproduction results from the union of a sperm and an egg. Answer: D 3) Strictly speaking, the phrase "like begets like" refers to A) all forms of reproduction. B) sexual reproduction only. C) asexual reproduction only. D) production of gametes from a premeiotic cell. E) sexual reproduction between different species. Answer: C 4) Asexual reproduction requires ________ individual (s). A) 0 B) 1 C) 2 D) 3 E) 4 Answer B 5) With the exception of identical twins, siblings who have the same two biological parents are likely to look similar, but not identical, to each other because we have A) identical chromosomes, but different genes. B) identical genes but different chromosomes. C) the same combination of traits...
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...The difference between the cell cycles of a normal and cancerous cell is that the cancerous cell is uncontrolled when it reaches the cell division or anything else goes wrong threwout the cycle(can be very dangerous) and the normal cell is controlled throughout the whole cycle. In the g1 phase, the cell synthesizes mRNA and proteins in preparation for subsequent steps leading to mitosis. When the cell reaches the end of the G1 phase it is controlled at a checkpoint called G1/S, G1/S is when the cell decides whether or not to replicate its DNA. At the checkpoint the cell is checked for DNA. Cells with no damaged DNA (normal cells) continue to S phase, in S phase cells with damaged DNA (cancerous cells) that cannot be repaired die. G2 is when cell is about to divide. the M is...
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...Cell division is the basic of reproduction for all living things. It is important and indeed in all living organisms. It enables the multicellular organisms to grow until the adult size, when the cell division plays role in reproducing cell into more new cells. Besides, cell division also replaces the worn-out or damaged cells in order to maintain the total cells numbers in a mature individual relatively constant. For instance is, there are millions of cells in human’s body will divide themselves every second, keeping the total number of them in about 100 trillion (Campbell, Reece, Taylor, Simon & Dickey, 2012). Process of cell division is a main component of the cell cycle. A cell cycle is known as an ordered sequence of events that extends...
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...Ruth Lin, 47985106 FRST302 Assignment 2 Jan 31, 2015 Describe the activities of chromosomes and microtubules in the cell cycle, including all phases of mitosis and meiosis. Mitosis is a part of the M phase in a cell’s life cycle process whereby cellular division occurs to form two genetically identical daughter cells. The cell cycle consists of the interphase phase and the M phase. The interphase phase represents the period between cells divisions, where the cell grows and develops. The M phase (mitotic phase) represents the period of active cell division, whereby copies of the cell’s chromosomes (sister chromatids) separate, so that a duplicate set of genetic information can be passed down to each of the daughter cells. Mitosis is often...
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