Nature vs. Nurture Does the environment affect the traits of an organism?

Fill It In … Nature = ________________ Nurture = ________________ Nature = ________________ Nurture = ________________

Nature vs Nurture F The environment does influence the expression of genes by chemically interacting with DNA or the cell, or by limiting available resources the organism requires to express the gene. F Ex. The gene for the dark pigment (protein) for coat color in Siamese cats is activated by colder temperature. g + e = p

Nature vs Nurture F Environmental hazards can create genetic mutations, turning off or altering the expression of a gene. F These hazards are called mutagens. F Ex. Many environmental toxins mimic human hormones such as estrogen and therefore inhibit the production of that hormone by the cell

Nature vs Nurture F Identical twins are often used to study the effects of the environment on gene expression. F This is because identical twins have identical genes but are often exposed to different environments.

Nature vs Nurture F There is a cause-and- effect relationship between environmental factors and expression of a particular genetic trait

Nature vs Nurture F Lung/mouth cancer is linked to tobacco use. F All tobacco products contain toxins and carcinogens. F Carcinogens can change the DNA, causing uncontrolled cell division (cancer)

Nature vs Nurture F Skin cancer, sun exposure, vitamin D production, and folic acid share a complex relationship

Nature vs Nurture F Skin cancer is directly linked directly to sun exposure. F UV rays mutate DNA, causing cancer.

Nature vs Nurture F When absorbed by the skin, sunlight also destroys folate (folic acid). F Folic acid is the key to DNA repair of mutations (like those caused by the sun). F Folic acid deficiency is a contributor to skin cancer risks. F Folic acid can be supplemented with food or vitamins.

Nature vs Nurture F However, sun exposure is also one of the ways our body can gain vitamin D, a vitamin that helps protect us from heart disease among other health benefits.

Nature vs Nurture F When the sun’s UV-B rays hit the skin, it causes a chemical reaction that produces vitamin D. F You only need about 10 minutes of exposure a day, at most, and can also supplement with food and vitamin pills.

Nature vs Nurture F Diabetes (especially Type 2 Diabetes) is linked to diet/exercise with genetic interaction. F It is possible to delay or prevent type 2 diabetes by exercising and losing weight, even if there is a strong family history.

Nature vs Nurture F Heart disease is also linked to diet/exercise with genetic interaction. F Different genes or gene combinations respond differently to changes in diet, health choices such as smoking, and exercise. F So far, 40 or more genes have been identified that are linked to cardiovascular health.

As the seasons change, the Arctic fox changes the color of its coat. In the spring and summer, it has a dark coat, to match the brown dirt in its environment. In the fall and winter, it turns white, to match the surrounding snow. Reproduced with permission of the Minister of Public Works & Government Services Canada, 2001

Fill It In … For each EFFECT, list the probable CAUSE(S): 1. Lung cancer - __________________ 2. Skin cancer - ___________________ 3. Diabetes - _____________________ 4. Heart disease - _________________ For each EFFECT, list the probable CAUSE(S): 1. Lung cancer - __________________ 2. Skin cancer - ___________________ 3. Diabetes - _____________________ 4. Heart disease - _________________

Check Yourself! 1. Are genes “nature” or “nurture”? 2. How can the environment affect genes?

Lick your Rats

Check Yourself! 1. Are genes “nature” or “nurture”? NATURE 2. How can the environment affect genes? BY CHEMICALLY INTERACTING WITH DNA OR THE CELL, OR BY LIMITING AVAILABLE RESOURCES REQUIRED TO EXPRESS THE GENE