Health Facts and Statistics About Cigarette Smoking

Health Facts and Statistics About Cigarette Smoking Addiction Nicotine Use Smoking-Related Diseases Print Important Statistics About Cigarette Smoking By Terry Martin facebook twitter Terry Martin quit smoking after 26 years and is now an advocate for those seeking freedom from nicotine addiction. Learn about our editorial policy Terry Martin Medically reviewed by Medically reviewed by Sanja Jelic, MD on August 05, 2016 Sanja Jelic, MD, is board-certified in sleep medicine, critical care medicine, pulmonary disease, and internal medicine.   Learn about our Medical Review Board Sanja Jelic, MD Updated on January 23, 2020 Peter Dazeley/Photographers Choice/Getty Images More in Addiction Nicotine Use Smoking-Related Diseases After You Quit How to Quit Smoking Nicotine Withdrawal The Inside of Cigarettes Alcohol Use Addictive Behaviors Drug Use Coping and Recovery As of December 20, 2019, the new legal age limit is 21 years old for purchasing cigarettes, cigars, or any other tobacco products in the U.S. We all know that smoking cigarettes is horribly destructive and in many  cases, deadly, killing half of all people who dont quit. Over 7,000 chemicals have been identified in cigarettes and cigarette smoke to date, 93 of which are harmful or potentially harmful, and more than 70 of which can cause cancer.?? These  ingredients and additives  affect everything from the internal functioning of your organs to the efficiency of your bodys immune system. Some of the facts and statistics about smoking may surprise you.   Toxic Ingredients in Cigarette Smoke The chemicals in cigarette smoke are inhaled into the lungs and from there travel throughout the body, causing damage: Nicotine reaches the brain in seven to 10 seconds after smoke is inhaled. Nicotine has been found in every part of a smokers body, including breast milk. Its also as addictive as heroin.??Carbon monoxide, which is present in cigarette smoke, binds to hemoglobin in red blood cells, preventing these cells from carrying all of the oxygen they normally would. This can lead to symptoms of carbon monoxide poisoning.Cancer-causing agents (carcinogens) in tobacco smoke damage important genes that control the growth of cells, causing them to grow abnormally or to reproduce too rapidly. More than 70 such cancer-causing chemicals have been identified in cigarette smoke to date.Smoking affects how the immune system functions by causing oxidative stress. This, in turn, causes DNA mutation, setting the stage for cancer and heart disease. Oxidative stress is also thought to be a contributor to the aging process, as smokers have fewer antioxidantsâ€"natures way of combating the damage oxidative stre ss causes to the bodys cellsâ€"in their blood than non-smokers.Smoking is associated with higher levels of chronic inflammation,?? another damaging process that may result in oxidative stress.Cigarette smoke contains radioactive heavy metals that stick to the tar that collects in the lungs of smokers. Over time, this builds up and is believed to be one of the risk factors for lung cancer in smokers.?? Increased Health Risks Smokers face a substantial increase in their risk for a number of diseases over those who dont smoke:Coronary heart disease: 2 to 4 timesStroke: 2 to 4 timesLung cancer risk for men: 25 timesLung cancer risk for women: 25.7 timesChronic obstructive pulmonary disease (COPD)-related death: 12 to 13 times The Health Benefits of Smoking Cessation Cigarette Smoking and Death Tobacco use is the leading cause of preventable death in the world today. Here are the statistics on smoking cigarettes and the number of deaths smoking causes:?? In the U.S., cigarette smoking accounts for approximately 480,000 deaths a year. Globally, nearly 6 million people die from tobacco use annually, and if current trends continue, that number is expected to increase to eight million by the year 2030.If no one smoked, cancer deaths in the U.S. would decrease by one-third.Lung cancer is largely a smokers disease; 90% of men and 80% of women who succumb to lung cancer smoked.COPD-related deaths are also primarily caused by smoking, with 90% of these deaths traced back to cigarettes.Smokers die 10 years sooner than non-smokers, on average.More than 41,000 die per year from exposure to secondhand smoke. Tobacco use is responsible for more deaths each year in the U.S. than all of the following combined: Human immunodeficiency virus (HIV), motor vehicle injuries, alcohol use, and illegal drug use.?? Reasons Why You Should Consider Quitting Smoking

Crows, Ravens and Jays - Corvidae - The Animal Encyclopedia

Crows, ravens and jays (Corvidae) are a group of perching birds that also includes jackdaws, rooks, magpies, nutcrackers, choughs and treepies. In total, there are more than 120 species that belong to the crow family. Crows, ravens and jays are medium to large birds. The group includes the largest members of the perching birds. Many crows, ravens and jays have large wingspans. They have a robust body, strong feet and sturdy bills. Their nares (nasal openings) are fringed by bristle-like feathers known as rictal bristles. In temperate areas, most members of the group are partly or entirely black, blue, iridescent blue or iridescent purple. Some species, such as the magpies and jays, are more varied in color. They might have plumage with a mixture of black, white, grey and blue markings. Members of this group of birds are thought to be highly intelligent, not just among birds but among all animals. Crows and rooks have demonstrated tool making abilities while European magpies have exhibited self-awareness in mirror tests. Many members of the crow family establish and protect territories either during the breeding season or throughout the year. When threatened, some corvids can defend their offspring or territories aggressively and are known to attack large animals such as other birds, dogs or cats. Many species of corvids form social groups and hierarchies for foraging and breeding. Many species of corvids have flourished in human environments. But while such species have enjoyed healthy populations, a few corvids have experienced declines. Examples of threatened members of the crow family include the Florida scrub jay, the Mariana crow and the New Zealand raven. Crows and their relatives form strong pair bonds and in some species this association is life-long. In most species, nests are constructed in trees or on rock ledges. Nests are built using twigs, grass and other plant materials. Females lay between 3 and 10 eggs and young fledge after about 10 days. The largest member of the crow family is the common raven which grows to more than 26 inches in length and weighs 3 pounds. The smallest member of the crow family is the dwarf jay which grows to about 8 inches and weighs little more than an ounce. Crows, ravens and jays have a nearly-worldwide distribution. They are absent from only the southern tip of South America and the polar regions. The group is most diverse in tropical regions of Central America, South America, Asia and Europe. Most members of the crow family do not migrate although when food shortages occur, populations do relocate. Classification Animals Chordates Birds Perching Birds Crows, Ravens and Jays The crows, ravens and jays are divided into about a dozen subgroups, some of which include New World jays, grey jays, azure-winged magpies, Holarctic magpies, Stresemanns bushcrow, piapiac, true crows, nutcrackers, Old World jays, Oriental magpies, treepies and choughs. The crow family is thought to have originated in Australia and spread throughout the world. The closest relatives of the crows, ravens and jays are thought to be the birds of paradise and shrikes. There remains considerable ambiguity regarding the exact lineages and their relationships within the crow family. The earliest members of the crow family date back about 17 million years ago to the middle Miocene. Known fossils include Miocorvus, Miocitta, Miopica and Henocitta. Crows, ravens and jays feed a variety of foods including small mammals, birds, invertebrates as well as fruits, seeds and berries. Some members of the crow family feed on insects such as grasshoppers while others feed on carrion.

Sigmund Freud s Psychoanalysis Theory - 2380 Words

Contemporaries of Sigmund Freud’s Psychoanalysis Theory Kevin Stout Florida Institute of Technology Abstract Sigmund Freud created psychoanalysis, a system through which an expert unloads oblivious clashes in light of the free affiliations, dreams and dreams of the patient. Psychoanalytic hypothesis is a strategy for exploring and treating identity issue and is utilized as a part of psychotherapy. Included in this hypothesis is the way to go that things that happen to individuals amid adolescence can add to the way they later capacity as grown-ups (Gay, 1998). Freud s psychodynamic methodology has prompted numerous insightful contemporaries and their theories that show an evolution of Freud’s psychoanalysis. This paper will show you some of the contemporaries and their theories that were influenced by Freud. Some of these theories extend Freud’s theory, and some sort of disagree with his thinking. However, it is obvious that Freud made a mark on these psychologists, and proved to be a big influence in the field of psychology. Contemporaries of Sigmund Freud’s Psychoanalysis Theory Sigmund Freud created psychoanalysis, a system through which an expert unloads oblivious clashes in light of the free affiliations, dreams and dreams of the patient. Psychoanalytic hypothesis is a strategy for exploring and treating identity issue and is utilized as a part of psychotherapy. Included in this hypothesis is the way to goShow MoreRelatedSigmund Freud s Theory Of Psychoanalysis2367 Words   |  10 Pages Sigmund Freud created psychoanalysis, a system through which an expert unloads oblivious clashes in light of the free affiliations, dreams and dreams of the patient. Psychoanalytic hypothesis is a strategy for exploring and treating identity issue and is utilized as a part of psychotherapy. Included in this hypothesis is the way to go that things that happen to individuals amid adolescence can add to the way they later capacity as grown-ups (Gay, 1998). Freud s psychodynamic methodology has promptedRead MoreSigmund Freud s Theory Of Psychoanalysis1339 Words   |  6 PagesSigmund Freud Biographic Description of Sigmund Freud Sigmund Freud was born on May 6, 1856 in Freiberg (currently known as Czech Republic). Freud is best known as the founder of psychoanalysis, which entails a scientific analysis of unpacking unconscious conflicts based on free associations, fantasies, and dreams of the patient. He was among the greatest psychologists of the 20th century, and his legacy lasts up to now. While young (4 years old), his family relocated to Vienna where he lived andRead MoreSigmund Freud s Theory Of Psychoanalysis1413 Words   |  6 PagesEver since Sigmund Freud developed psychoanalysis theory, its applicability has been extended beyond therapy to literature. In the interpretation of dreams, Sigmund Freud coins the term the oedipus complex in reference to the greek mythology of Oedipus the king. The application of psychoanalysis to myth is treated by Dowden with scepticism and he states that the only significance of the psychoanalytic approach is in its recognition of how fundamental the images that recu r in the myth are (DowdenRead MoreSigmund Freud s Theory Of Psychoanalysis1258 Words   |  6 Pages Sigmund Freud’s grand theory of Psychoanalysis was developed in the 19th century. He especially worked to prove that childhood events had a great and powerful impact on the teenage and adult mind in later years to come. Sigmund Freud was born in 1856 and died in 1939. He had a great desire to find treatment for psychopathology that all began with a great deal of time spent at Theodor Meynert’s Psychiatric Clinic. His time spent here was what created his desire to help people and find new ways toRead MoreSigmund Freud s Theory Of Psychoanalysis Essay1691 Words   |  7 Pages Freud’s theological perspective was termed Psychoanalysis. Freud believed people unconsciously repressed information, and that this hidden information was the cause of their distress. The unconscious is the space in your brain where thoughts, feelings, and desires are tucked away, and canno t be readily drawn upon and available to the conscious mind. Because 99% of this methodology is dealing with the unconscious, Freud believed that success could not be reached by the individual alone, rather theyRead MoreSigmund Freud s Theories About Psychoanalysis And The Unconscious Mind1003 Words   |  5 PagesPsychology, 5th Block Sigmund Freud s Theories about Psychoanalysis and the Unconscious Mind Sigmund Freud was well known for his theories on psychoanalysis, and it was used to help understand the unconscious mind better. In Freud s lifetime, he grew to be a very influential person of the twentieth century. The western society still uses words that he introduced in his time, some are libido, repression, denial, and neurotic. He was the founding father of the theory of psychoanalysis, which explains humanRead MoreThe Power Of Sigmund Freud s Theory Of Psychoanalysis1440 Words   |  6 PagesThe power of Sigmund Freud’s theory Sigmund Freud was a great philosopher who predicted and came up with theories that are widely used in todays society. He is often referred to the father of psychoanalysis as he was one of the first people to analyze the human mind. He separated the human mind into three parts which help further explain the theory of psychoanalysis. The first part is known as the id, it is the part of the mind that deals with instincts. It is the unconscious part of the mindRead MoreHistorical Background Of Sigmund Freud s Theory Of Psychoanalysis774 Words   |  4 PagesHistorical Background Sigmund Freud dedicated the majority of his time on this earth to mainly covering his theory of psychoanalysis. He did not however have a lot of patience from contemporaries who diverged from his psychoanalytic principles. He attempted to keep control over the movement by expelling those who dared to disagree. Carl Jung and Alfred Alder, for example, worked closely with Freud, but each founded his own therapeutic school after repeated disagreements with Freud on theoretical andRead MoreThe Theory Of Psychoanalysis On The Unconscious Phases Of Personality Development1130 Words   |  5 PagesThe theory of Psychoanalysis In the early 1800s, Psychologist and researchers were fervent in postulating and hypothesizing. Searching earnestly for answers to the many questions that were prevalent in those days. The theory of Psychoanalysis was one of such theory that was founded. Psychoanalysis emphases on the unconscious phases of personality development. The main tenets of this theory are characterized into four subsections. Firstly, it states that early childhood experiences are important inRead MoreSigmund Freud s Theory Of Psychology1283 Words   |  6 PagesSigmund Freud (1856-1939), is a pioneer in the field of psychology in various ways. His dedication to his field helped shape the minds of many nineteen-century contemporary schools of thought. Most notably, Freud’s work in psychoanalytic theory, according to Tan (2011) earned him the title of, â€Å"father of psychoanalysis† (p. 322). Moreover, Tan Taykeyesu (2011) report that Freud’s genius is not just in psychoanalysis, but also when we â€Å"think Oedipus complex, infantile sexuality, and repression†

Resotech Inc. Free Essays

Resotech Inc. Time is a critical strategic challenge. For example, assume you are a customer being interested in a particular product. We will write a custom essay sample on Resotech Inc. or any similar topic only for you Order Now This product is very expensive and long lasting. It’s capacity is more than you need. Once you’ve bought it, you can use it for decades. Even product improvements and new versions would only rarely make you buying a new one, simply because they’re incredible expensive. A secondary market to sell the product might exist, but anyway you’d have to sell it at a discount due to technology improvements. The main question for you as a consumer is the following: How many products do you buy? The answer is simple: One. What does that mean for companies offering solely such a product? If a customer buys a particular product only once and stays with it, only one company can serve this customer. The company, that first sells to him or her, wins. The competitors have no chance to convince the customer to switch or to buy the next time from them, since there is no next time. This reveals our strategic challenge: Time. If a company is the first launching a product, it has a first-mover-advantage. If a company is second, a part of the market is already served, hence, the total demand and the maximum revenues decreased. How can companies be successful in such an environment? There’s only one way: Be the first! Either because there’s no follower (you’re a monopolist), or because you launch the product earlier than your competitors do. This implies for any company that whatever it does, it must ensure that the product is launched before the competitors launch their products (staying out of the market is no option since it’s the company’s only product). This brings us to the question of available resources. How many resources you have to invest to be the first mainly depends on how many resources your competitor’s are investing. Moreover, if they suddenly increase their investments trying to outpace you, you should be able to react. What does that mean for Resotech Inc.? The company is known for its amazing quality. The products are of superior technology and benefit from a â€Å"Rolls-Royce† image. This implies that a lot of time must be spent on RD for developing a mobile scanner of such a quality. Delivery delays are possible, or even probable, as it were the case for the RS-1000. Moreover, the development might also lead to a delay of the RS-2000 due to limited RD resources. And what if the competitors enter the market as well? One can argue that Resotech might be able to discourage other companies to enter the mobile market once they committed themselves. However, this is unlikely for two reasons: First, Resotech is a relatively small company. Larger companies such as GE, Siemens, and Picker will probably have a shorter product development cycles due to their huge financial reserves and experience. Second, Resotech aims for high quality products. Competitors are able to produce less advanced scanners and enter the market first. In contrast, this is no option for Resotech. Moreover, Resotech would have to acquire new personnel first. To summarize, Resotech could sell 25 units. However, there’s a risk that Resotech is not able to stick to its delivery schedule, since the development of a mobile product is â€Å"not a piece of cake†. This may result in penalties. Additionally, if we try to stick to the schedule with a less advanced product, we will damage our image as quality leader. Moreover, what if 25 units are not enough to break even and another competitor has already entered the market? If Resotech accepts the offer, it won’t have any spare resources to accelerate RD to outpace potential entrants. On top of that, we put the RS-2000 at a risk of being launched too late, since we might face a shortage of RD capacity for both products. Therefore, from a time point of view, I recommend to decline the offer. Thereby we can focus on the RS-2000 and launch it earlier. Declining would be less risky, but maybe less profitable. It’s the safe way. How to cite Resotech Inc., Essay examples

The People Of The Kalahari Desert Essays - San People, Ergs

The People of the Kalahari Desert Part One Introduction, Location and Environment The people of the Kalahari desert are extraordinary people. For centuries their hunting and food gathering techniques have enabled them to survive in the difficult environment of the dry, hot and barren Kalahari desert. They are known as the Bushmen. Or the Kung or the Gikwe since Bushmen is rather discriminating because the "Bushmen" live among shrubs and trees and sand and such. The people of Kalahari Desert live in a dry bush desert in South-West Africa and western Bechuanaland, bordered in the North by Lake Ngami and the Okovngo River in the South by the Orange river and west by the Damera Hills. The Kalahari is there all low with sand dunes and great plains. A hostile country of thirst and heat. A country with scorpions, thorny bushes and of course sand as far as the eye can see and perpetual dust. In the hot months it the temperature goes up to 120 degrees Fahrenheit. In the months of winter, which are June and July, the winds from the Antarctic cold blow at night. But during the day it eventually rises up to around 80 degrees Fahrenheit and drops down in the evening. There are only three months of winter and these begin in December and in March the drought season starts and by August all the water holes that were made during the rainy season are dried up. It is not dead, the desert. There are boabab trees that give pear shaped fruits, flowers, and blossoms resembling gardenias. There are tall grasses. There are bushes flowering either red, white or violet flowers, tsama melons which very much look like watermelons and are the size of a small cantaloupe. There are also mogongo nuts that are very high in protein. When in season one person can eat as many as 400 nuts. These people who inhabit the dry, barren Kalahari have a hard life, so it seems... But, really, do they? Part two Food Resources and Technology Living in the hot sandy Kalahari might seem very difficult, even impossible. But if one knows the secrets of the desert. The desert will give you a living. The people of the Kalahari know these secrets. No fancy machinery necessary. No modern technology needed. Only simple handmade tools and weapons such as digging sticks, little axes, bows and arrows, small traps or snares, knives. Not to mention their senses and their wits. They poison the arrows so the game will die faster when hit. The poison is extracted from a certain grub. Great hunters know where the best place to shoot an animal so the poison will work best. Great hunters also know how to make the finest arrows. They also know all the habits of all the animals from the mice to the antelopes, they know what time of day that is best for hunting, too. There are quite a few food resources such as tsama melons, mongongo nuts, roots, berries, wildebeests, kudu, gemsbok, antelopes, steenbok, porcupines, elands, small animals like the mongoose and the chicken fowl, birds- even babies-, wild boars as well as honey from the bees. And of course there are a couple of temporary and permanent water holes around. They use digging sticks to dig up roots, they gather tsama melons, mongongo nuts, and berries. They hunt game with bows and arrows and spears on foot. They cook mongongo nuts in hot ashes, eat the entire animal from the hide-which they work into leather sometimes- to the marrow inside the bones. Of course this might seem like a lot a meat since the game is plentiful but really 80 percent of their diet is vegetables. Sometimes when cooking meat they cook it in the rind of the tsama melon with the liquid still inside and it makes a stew. The people are smart and know their land very well. Therefore as long as they know the secrets the hot desert holds, the desert will give them a living and they'll never go hungry. Part three Social System and Leisure The size of the groups vary from 20 to 100 people or even 200 people per group. The groups have to be small or else moving from place to place will be extremely difficult. The roll of a man is to hunt and gather honey from the bees. The roll of the woman is to gather and dig for roots and taste them to see

Dead Metaphor Definition and Examples

Dead Metaphor Definition and Examples A dead metaphor is traditionally defined as a  figure of speech that has lost its force and imaginative effectiveness through frequent use. Also known as a  frozen metaphor or a historical metaphor. Contrast with creative metaphor. Over the past several decades, cognitive linguists have criticized the dead metaphor theory- the view that a conventional metaphor is dead and no longer influences thought: The mistake derives from a basic confusion: it assumes that those things in our cognition that are most alive and most active are those that are conscious. On the contrary, those that are most alive and most deeply entrenched, efficient, and powerful are those that are so automatic as to be unconscious and effortless. (G. Lakoff and M. Turner, Philosophy in the Flesh. Basic Books, 1989) As  I.A. Richards said back in 1936: This favorite old distinction between dead and living metaphors (itself a two-fold metaphor) needs a drastic re-examination (The Philosophy of Rhetoric) Examples and Observations Kansas City is oven hot, dead metaphor or no dead metaphor. (Zadie Smith, On the Road: American Writers and Their Hair, July 2001)An example of a dead metaphor would be the body of an essay. In this example, body was initially an expression that drew on the metaphorical image of human anatomy applied to the subject matter in question. As a dead metaphor, body of an essay literally means the main part of an essay, and no longer suggests anything new that might be suggested by an anatomical referent. In that sense, body of an essay is no longer a metaphor, but merely a literal statement of fact, or a dead metaphor. (Michael P. Marks, The Prison as Metaphor. Peter Lang, 2004)Many venerable metaphors have been literalized into everyday items of language: a clock has a face (unlike human or animal face), and on that face are hands (unlike biological hands); only in terms of clocks can hands be located on a face. . . . The deadness of a metaphor and its status as a clichà © are relative m atters. Hearing for the first time that life is no bed of roses, someone might be swept away by its aptness and vigor. (Tom McArthur, Oxford Companion to the English Language. Oxford University Press, 1992) [A] so-called dead metaphor is not a metaphor at all, but merely an expression that no longer has a pregnant metaphorical use. (Max Black, More About Metaphor. Metaphor and Thought, 2nd ed., ed. by Andrew Ortony. Cambridge University Press, 1993) It's Alive! The dead metaphor account misses an important point: namely, that what is deeply entrenched, hardly noticed, and thus effortlessly used is most active in our thought. The metaphors . . . may be highly conventional and effortlessly used, but this does not mean that they have lost their vigor in thought and that they are dead. On the contrary, they are alive in the most important sense- they govern our thought- they are metaphors we live by. (Zoltn Kà ¶vecses, Metaphor: A Practical Introduction. Oxford University Press, 2002) Two Kinds of Death The expression dead metaphor- itself metaphorical- can be understood in at least two ways. On the one hand, a dead metaphor may be like a dead issue or a dead parrot; dead issues are not issues, dead parrots, as we all know, are not parrots. On this construal, a dead metaphor is simply not a metaphor. On the other hand, a dead metaphor may be more like a dead key on a piano; dead keys are still keys, albeit weak or dull, and so perhaps a dead metaphor, even if it lacks vivacity, is metaphor nonetheless. (Samuel Guttenplan, Objects of Metaphor. Oxford University Press, 2005) The Etymological Fallacy To suggest that words always carry with them something of what may have been an original metaphoric sense is not only a form of etymological fallacy; it is a remnant of that proper meaning superstition which I.A. Richards so effectively critiques. Because a term is used which was originally metaphorical, that is, which came from one domain of experience to define another, one cannot conclude that it necessarily continues to bring with it the associations which it had in that other domain. If it is a truly dead metaphor, it will not. (Gregory W. Dawes, The Body in Question: Metaphor and Meaning in the Interpretation of Ephesians 5:21-33. Brill, 1998)

Daughter Cells and Chromosome Number in Mitosis and Meiosis

Daughter Cells and Chromosome Number in Mitosis and Meiosis Daughter cells are cells that result from the division of a single parent cell. They are produced by the division processes of mitosis and meiosis. Cell division is the reproductive mechanism whereby living organisms grow, develop, and produce offspring. At the completion of the mitotic cell cycle, a single cell divides forming two daughter cells. A parent cell undergoing meiosis produces four daughter cells. While mitosis occurs in both prokaryotic and eukaryotic organisms, meiosis occurs in eukaryotic animal cells, plant cells, and fungi. Daughter Cells in Mitosis Mitosis is the stage of the cell cycle that involves the division of the cell nucleus and the separation of chromosomes. The division process is not complete until after cytokinesis, when the cytoplasm is divided and two distinct daughter cells are formed. Prior to mitosis, the cell prepares for division by replicating its DNA and increasing its mass and organelle numbers. Chromosome movement occurs in the different phases of mitosis: ProphaseMetaphaseAnaphaseTelophase During these phases, chromosomes are separated, moved to opposite poles of the cell, and contained within newly formed nuclei. At the end of the division process, duplicated chromosomes are divided equally between two cells. These daughter cells are genetically identical diploid cells that have the same chromosome number and chromosome type. Somatic cells are examples of cells that divide by mitosis. Somatic cells consist of all body cell types, excluding sex cells. The somatic cell chromosome number in humans is 46, while the chromosome number for sex cells is 23. Daughter Cells in Meiosis In organisms that are capable of sexual reproduction, daughter cells are produced by meiosis. Meiosis is a two part division process that produces gametes. The dividing cell goes through prophase, metaphase, anaphase, and telophase twice. At the end of meiosis and cytokinesis, four haploid cells are produced from a single diploid cell. These haploid daughter cells have half the number of chromosomes as the parent cell and are not genetically identical to the parent cell. In sexual reproduction, haploid gametes unite in fertilization and become a diploid zygote. The zygote continues to divide by mitosis and develops into a fully functioning new individual. Daughter Cells and Chromosome Movement How do daughter cells end up with the appropriate number of chromosomes after cell division? The answer to this question involves the spindle apparatus. The spindle apparatus consists of microtubules and proteins that manipulate chromosomes during cell division. Spindle fibers attach to replicated chromosomes, moving and separating them when appropriate. The mitotic and meiotic spindles move chromosomes to opposite cell poles, ensuring that each daughter cell gets the correct number of chromosomes. The spindle also determines the location of the metaphase plate. This centrally localized site becomes the plane on which the cell eventually divides. Daughter Cells and Cytokinesis The final step in the process of cell division occurs in cytokinesis. This process begins during anaphase and ends after telophase in mitosis. In cytokinesis, the dividing cell is split into two daughter cells with the help of the spindle apparatus. Animal Cells In animal cells, the spindle apparatus determines the location of an important structure in the cell division process called the contractile ring. The contractile ring is formed from actin microtubule filaments and proteins, including the motor protein myosin. Myosin contracts the ring of actin filaments forming a deep groove called a cleavage furrow. As the contractile ring continues to contract, it divides the cytoplasm and pinches the cell in two along the cleavage furrow. Plant Cells Plant cells do not contain asters, star-shaped spindle apparatus microtubules, which help determine the site of the cleavage furrow in animal cells. In fact, no cleavage furrow is formed in plant cell cytokinesis. Instead, daughter cells are separated by a cell plate formed by vesicles that are released from Golgi apparatus organelles. The cell plate expands laterally and fuses with the plant cell wall forming a partition between the newly divided daughter cells. As the cell plate matures, it eventually develops into a cell wall. Daughter Chromosomes The chromosomes within daughter cells are termed daughter chromosomes. Daughter chromosomes result from the separation of sister chromatids occuring in anaphase of mitosis and anaphase II of meiosis. Daughter chromosomes develop from the replication of single-stranded chromosomes during the synthesis phase (S phase) of the cell cycle. Following DNA replication, the single-stranded chromosomes become double-stranded chromosomes held together at a region called the centromere. Double-stranded chromosomes are known as sister chromatids. Sister chromatids are eventually separated during the division process and equally distributed among newly formed daughter cells. Each separated chromatid is known as a daughter chromosome. Daughter Cells and Cancer Mitotic cell division is strictly regulated by cells to ensure that any errors are corrected and that cells divide properly with the correct number of chromosomes. Should mistakes occur in cell error checking systems, the resulting daughter cells may divide unevenly. While normal cells produce two daughter cells by mitotic division, cancer cells are distinguished for their ability to produce more than two daughter cells. Three or more daughter cells may develop from dividing cancer cells and these cells are produced at a faster rate than normal cells. Due to the irregular division of cancer cells, daughter cells may also end up with too many or not enough chromosomes. Cancer cells often develop as a result of mutations in genes that control normal cell growth or that function to suppress cancer cell formation. These cells grow uncontrollably, exhausting the nutrients in the surrounding area. Some cancer cells even travel to other locations in the body via the circulatory system or lymphatic system.