{"id":2765,"date":"2016-06-13T17:29:05","date_gmt":"2016-06-13T17:29:05","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/biologyxwaymakerxmaster\/?post_type=chapter&#038;p=2765"},"modified":"2024-04-26T00:22:59","modified_gmt":"2024-04-26T00:22:59","slug":"reading-effect-of-the-environment","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/chapter\/reading-effect-of-the-environment\/","title":{"raw":"Effect of the Environment","rendered":"Effect of the Environment"},"content":{"raw":"<div class=\"textbox learning-objectives\">\r\n<h3>Learning Outcomes<\/h3>\r\n<ul>\r\n \t<li>Identify gene-environment interaction and how this impacts trait expression<\/li>\r\n<\/ul>\r\n<\/div>\r\nCharacteristics that are influenced by environmental as well as genetic factors are called <strong>multifactorial<\/strong>. The idea of \u201cnature versus nurture\u201d \u2014 in other words, the relative influence of genetics versus environmental factors \u2014 has been and still is debated. Just looking at the genes of a given organism will not determine how that organism will develop and act. Even identical twins will show different characteristics, depending on the environment in which they live. Everyone is a product of their environment as well as their genetics.\r\n\r\n[caption id=\"attachment_2800\" align=\"alignright\" width=\"350\"]<img class=\"wp-image-2800\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/110\/2016\/06\/13172732\/baby_foot.png\" alt=\"Blood from a newborn's foot is being placed on a card.\" width=\"350\" height=\"202\" \/> Figure 1. Taking a newborn blood sample for PKU testing. By Staff Sgt Eric T. Sheler, U.S. Air Force (Phenylketonuria testing) Public Domain[\/caption]\r\n\r\nEven when influenced by the environment, phenotypes have a normal range of expression. For instance, human height varies based on nutrition and genetics, but not many people are shorter than 4\u00bd feet or taller than 7 feet. The range of phenotypic possibilities is called the <span style=\"text-decoration: underline;\"><em>norm of reaction<\/em><\/span>. Hydrangeas, for example, may be blue, pink, or purple, but they are never naturally orange. Hydrangeas are blue in acidic soil with available aluminum, and they are pink in alkaline soil without available aluminum.\r\n\r\nYou may have heard about PKU, a disorder caused by defects in a single gene coding for an enzyme that converts the amino acid phenylalanine to tyrosine. Newborns are tested for this defect very early in life (Figure 1), so that if the results are positive, they can be given a diet limiting phenylalanine ingestion. That way, the toxic buildup is prevented and the children can develop normally. PKU is an example in which environmental factors can modify gene expression.\r\n<div class=\"textbox exercises\">\r\n<h3>Practice Question<\/h3>\r\nTwo identical twins (female) live in different parts of the country. One is very committed to a\u00a0healthy lifestyle: not smoking, exercising regularly, eating a diet rich in fresh produce, and avoiding red\u00a0meats and processed foods. The other is not as careful: she smokes, is overweight, and often eats fast\u00a0and processed foods. They are aware that several women in their family have had breast cancer, and\u00a0decide to consult a doctor about their odds of developing the disease. Which of the following statements\u00a0by the doctor sounds most correct?\r\n<ol style=\"list-style-type: lower-alpha;\">\r\n \t<li>As identical twins, you are genetically the same, so your chances of developing breast cancer are identical.<\/li>\r\n \t<li>The twin with the healthy lifestyle should not be terribly concerned, while the one with the unhealthy lifestyle is at a higher risk.<\/li>\r\n \t<li>Breast cancer has a genetic component, and the twins have identical genes, so they have the same genetic risk. However, environmental factors such as smoking, obesity, and consumption of red meat have been shown to increase the risk of cancer. While both twins should monitor themselves closely, the twin who smokes and is overweight may want to consider a healthier lifestyle to decrease her risk of breast cancer.<\/li>\r\n<\/ol>\r\n[practice-area rows=\"2\"][\/practice-area]\r\n[reveal-answer q=\"41921\"]Show Answer[\/reveal-answer]\r\n[hidden-answer a=\"41921\"]Option A is wrong; while\u00a0it has been shown that certain genes may predispose people to cancer, there are many\u00a0associations between environmental effects and cancer. Option B is also wrong; familial cancers have a genetic component which may or may not be balanced by a healthy lifestyle. Option C is the most correct answer; lifestyle choices are important, but genetic influences are to be taken seriously, especially if\u00a0there is a family pattern associated with them.[\/hidden-answer]\r\n\r\n<\/div>\r\n<div class=\"textbox learning-objectives\">\r\n<h3>In Summary: Effect of the Environment<\/h3>\r\nWhile genes and genetic causes play a large role in health and phenotypes, the environment also plays an important role. Understanding this can enable the treatment of some disorders, such as the case with PKU in which limiting the intake of phenylalanine can prevent toxic build up of this amino acid. Often the norm of reaction is set by genetic factors but ultimately determined by environmental exposures.\r\n\r\n<\/div>\r\n<div class=\"textbox tryit\">\r\n<h3>Try It<\/h3>\r\nhttps:\/\/assess.lumenlearning.com\/practice\/15ab91dc-8e0f-49fa-9f39-700acc0b8061\r\n<\/div>","rendered":"<div class=\"textbox learning-objectives\">\n<h3>Learning Outcomes<\/h3>\n<ul>\n<li>Identify gene-environment interaction and how this impacts trait expression<\/li>\n<\/ul>\n<\/div>\n<p>Characteristics that are influenced by environmental as well as genetic factors are called <strong>multifactorial<\/strong>. The idea of \u201cnature versus nurture\u201d \u2014 in other words, the relative influence of genetics versus environmental factors \u2014 has been and still is debated. Just looking at the genes of a given organism will not determine how that organism will develop and act. Even identical twins will show different characteristics, depending on the environment in which they live. Everyone is a product of their environment as well as their genetics.<\/p>\n<div id=\"attachment_2800\" style=\"width: 360px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-2800\" class=\"wp-image-2800\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/110\/2016\/06\/13172732\/baby_foot.png\" alt=\"Blood from a newborn's foot is being placed on a card.\" width=\"350\" height=\"202\" \/><\/p>\n<p id=\"caption-attachment-2800\" class=\"wp-caption-text\">Figure 1. Taking a newborn blood sample for PKU testing. By Staff Sgt Eric T. Sheler, U.S. Air Force (Phenylketonuria testing) Public Domain<\/p>\n<\/div>\n<p>Even when influenced by the environment, phenotypes have a normal range of expression. For instance, human height varies based on nutrition and genetics, but not many people are shorter than 4\u00bd feet or taller than 7 feet. The range of phenotypic possibilities is called the <span style=\"text-decoration: underline;\"><em>norm of reaction<\/em><\/span>. Hydrangeas, for example, may be blue, pink, or purple, but they are never naturally orange. Hydrangeas are blue in acidic soil with available aluminum, and they are pink in alkaline soil without available aluminum.<\/p>\n<p>You may have heard about PKU, a disorder caused by defects in a single gene coding for an enzyme that converts the amino acid phenylalanine to tyrosine. Newborns are tested for this defect very early in life (Figure 1), so that if the results are positive, they can be given a diet limiting phenylalanine ingestion. That way, the toxic buildup is prevented and the children can develop normally. PKU is an example in which environmental factors can modify gene expression.<\/p>\n<div class=\"textbox exercises\">\n<h3>Practice Question<\/h3>\n<p>Two identical twins (female) live in different parts of the country. One is very committed to a\u00a0healthy lifestyle: not smoking, exercising regularly, eating a diet rich in fresh produce, and avoiding red\u00a0meats and processed foods. The other is not as careful: she smokes, is overweight, and often eats fast\u00a0and processed foods. They are aware that several women in their family have had breast cancer, and\u00a0decide to consult a doctor about their odds of developing the disease. Which of the following statements\u00a0by the doctor sounds most correct?<\/p>\n<ol style=\"list-style-type: lower-alpha;\">\n<li>As identical twins, you are genetically the same, so your chances of developing breast cancer are identical.<\/li>\n<li>The twin with the healthy lifestyle should not be terribly concerned, while the one with the unhealthy lifestyle is at a higher risk.<\/li>\n<li>Breast cancer has a genetic component, and the twins have identical genes, so they have the same genetic risk. However, environmental factors such as smoking, obesity, and consumption of red meat have been shown to increase the risk of cancer. While both twins should monitor themselves closely, the twin who smokes and is overweight may want to consider a healthier lifestyle to decrease her risk of breast cancer.<\/li>\n<\/ol>\n<p><textarea aria-label=\"Your Answer\" rows=\"2\"><\/textarea><\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q41921\">Show Answer<\/span><\/p>\n<div id=\"q41921\" class=\"hidden-answer\" style=\"display: none\">Option A is wrong; while\u00a0it has been shown that certain genes may predispose people to cancer, there are many\u00a0associations between environmental effects and cancer. Option B is also wrong; familial cancers have a genetic component which may or may not be balanced by a healthy lifestyle. Option C is the most correct answer; lifestyle choices are important, but genetic influences are to be taken seriously, especially if\u00a0there is a family pattern associated with them.<\/div>\n<\/div>\n<\/div>\n<div class=\"textbox learning-objectives\">\n<h3>In Summary: Effect of the Environment<\/h3>\n<p>While genes and genetic causes play a large role in health and phenotypes, the environment also plays an important role. Understanding this can enable the treatment of some disorders, such as the case with PKU in which limiting the intake of phenylalanine can prevent toxic build up of this amino acid. Often the norm of reaction is set by genetic factors but ultimately determined by environmental exposures.<\/p>\n<\/div>\n<div class=\"textbox tryit\">\n<h3>Try It<\/h3>\n<p>\t<iframe id=\"assessment_practice_15ab91dc-8e0f-49fa-9f39-700acc0b8061\" class=\"resizable\" src=\"https:\/\/assess.lumenlearning.com\/practice\/15ab91dc-8e0f-49fa-9f39-700acc0b8061?iframe_resize_id=assessment_practice_id_15ab91dc-8e0f-49fa-9f39-700acc0b8061\" frameborder=\"0\" style=\"border:none;width:100%;height:100%;min-height:300px;\"><br \/>\n\t<\/iframe>\n<\/div>\n\n\t\t\t <section class=\"citations-section\" role=\"contentinfo\">\n\t\t\t <h3>Candela Citations<\/h3>\n\t\t\t\t\t <div>\n\t\t\t\t\t\t <div id=\"citation-list-2765\">\n\t\t\t\t\t\t\t <div class=\"licensing\"><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Shared previously<\/div><ul class=\"citation-list\"><li>Application Spotlight: Effect of the Environment. <strong>Provided by<\/strong>: Open Learning Initiative. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/oli.cmu.edu\/jcourse\/workbook\/activity\/page?context=434a5f4180020ca600915a031e68a874\">https:\/\/oli.cmu.edu\/jcourse\/workbook\/activity\/page?context=434a5f4180020ca600915a031e68a874<\/a>. <strong>Project<\/strong>: Introduction to Biology (Open + Free). <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\">CC BY-NC-SA: Attribution-NonCommercial-ShareAlike<\/a><\/em><\/li><\/ul><\/div>\n\t\t\t\t\t\t <\/div>\n\t\t\t\t\t <\/div>\n\t\t\t <\/section>","protected":false},"author":17,"menu_order":16,"template":"","meta":{"_candela_citation":"[{\"type\":\"cc\",\"description\":\"Application Spotlight: Effect of the Environment\",\"author\":\"\",\"organization\":\"Open Learning Initiative\",\"url\":\"https:\/\/oli.cmu.edu\/jcourse\/workbook\/activity\/page?context=434a5f4180020ca600915a031e68a874\",\"project\":\"Introduction to Biology (Open + Free)\",\"license\":\"cc-by-nc-sa\",\"license_terms\":\"\"}]","CANDELA_OUTCOMES_GUID":"8af89cb3-cf05-41f9-b398-40ff5f20a57b, e2bc893e-6974-46c5-ba7e-48aa0aa739f1","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-2765","chapter","type-chapter","status-publish","hentry"],"part":258,"_links":{"self":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/pressbooks\/v2\/chapters\/2765","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/wp\/v2\/users\/17"}],"version-history":[{"count":18,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/pressbooks\/v2\/chapters\/2765\/revisions"}],"predecessor-version":[{"id":6750,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/pressbooks\/v2\/chapters\/2765\/revisions\/6750"}],"part":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/pressbooks\/v2\/parts\/258"}],"metadata":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/pressbooks\/v2\/chapters\/2765\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/wp\/v2\/media?parent=2765"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/pressbooks\/v2\/chapter-type?post=2765"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/wp\/v2\/contributor?post=2765"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/wp\/v2\/license?post=2765"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}