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Describe two essential roles played by visible radiation from the sun?
Wiki User
∙ 10y ago
Allows us to see and also drives photosynthesis.
Wiki User
∙ 10y ago
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What can UV light do to living things?
The sun radiates energy in a wide range of wavelengths, most of which are invisible to human eyes. The shorter the wavelength, the more energetic the radiation, and the greater the potential for harm. Ultraviolet (UV) radiation that reaches the Earth's surface is in wavelengths between 290 and 400 nm (nanometers, or billionths of a meter). This is shorter than wavelengths of visible light, which are 400 to 700 nm. UV radiation from the sun has always played important roles in our environment, and affects nearly all living organisms. Biological actions of many kinds have evolved to deal with it. Yet UV radiation at different wavelengths differs in its effects, and we have to live with the harmful effects as well as the helpful ones. Radiation at the longer UV wavelengths of 320-400 nm, called UV-A, plays a helpful and essential role in formation of Vitamin D by the skin, and plays a harmful role in that it causes sunburn on human skin and cataracts in our eyes. The incoming radiation at shorter wavelengths, 290-320 nm, falls within the UV-B part of the electromagnetic spectrum. (UV-B includes light with wavelengths down to 280 nm, but little to no radiation below 290 nm reaches the Earth's surface). UV-B causes damage at the molecular level to the fundamental building block of life- deoxyribonucleic acid (DNA). DNA readily absorbs UV-B radiation, which commonly changes the shape of the molecule in one of several ways. The illustration below illustrates one such change in shape due to exposure to UV-B radiation. Changes in the DNA molecule often mean that protein-building enzymes cannot "read" the DNA code at that point on the molecule. As a result, distorted proteins can be made, or cells can die. But living cells are "smart." Over millions of years of evolving in the presence of UV-B radiation, cells have developed the ability to repair DNA. A special enzyme arrives at the damage site, removes the damaged section of DNA, and replaces it with the proper components (based on information elsewhere on the DNA molecule). This makes DNA somewhat resilient to damage by UV-B. In addition to their own resiliency, living things and the cells they are made of are protected from excessive amounts of UV radiation by a chemical called ozone. A layer of ozone in the upper atmosphere absorbs UV radiation and prevents most of it from reaching the Earth. Yet since the mid-1970s, human activities have been changing the chemistry of the atmosphere in a way that reduces the amount of ozone in the stratosphere (the layer of atmosphere ranging from about 11 to 50 km in altitude). This means that more ultraviolet radiation can pass through the atmosphere to the Earth's surface, particularly at the poles and nearby regions during certain times of the year. Without the layer of ozone in the stratosphere to protect us from excessive amounts of UV-B radiation, life as we know it would not exist. Scientific concern over ozone depletion in the upper atmosphere has prompted extensive efforts to assess the potential damage to life on Earth due to increased levels of UV-B radiation. Some effects have been studied, but much remains to be learned.
Where can cosmic background radiation be found?
Cosmic Microwave Background Radiation has been discovered via WMAP mission and it is suggested that this has been left over from the Big Bang and galactic clusters are still moving away from each other at an ever increasing acceleration. WMAP's measurements played the key role in establishing the current Standard Model of Cosmology: the Lambda-CDM model. In the Lambda-CDM model of the observable universe, the age of the observable universe is 13.772 ± 0.059 billion years.
Roles played by the components of ecosystem?
roles played by the components
What movie and television projects has Kenya Brome been in?
Kenya Brome has: Played Halle Berry in "Celebrity Deathmatch" in 1998. Played Janet Jackson in "Celebrity Deathmatch" in 1998. Played Candy in "Third Watch" in 1999. Played Detective Teesh in "Downtown: A Street Tale" in 2004. Played Angela in "Breaking Point" in 2009. Played Reporter in "The Orphan Killer" in 2011. Played Radio Voices in "Saints Row: The Third" in 2011. Played Nurse Cody in "Bubble Girl" in 2014.
Who played Hades in The Lightning Thief?
Steve Coogan played the part of Hades .
Which group played an essential role in the building of the first transcontinental railroads?
Chinese Immigrants played a major role in building the first transcontinental railroad.
Which group played an essential role in the building of the first transcontinental railroad?
Chinese Immigrants played a major role in building the first transcontinental railroad.
Describe the changes in the Maritimes and the Quebec that resulted from the arrival of the Loyalists?
they played xbox
Describe a friend who has played an important role in your life?
I will describe a friend who has played an important part in my life!
What movie and television projects has Jeri Silverman been in?
Jeri Silverman has: Played Christie in "Christie" in 2012. Played Julie in "Visible" in 2013. Played Party Guest in "Opening Night" in 2013. Played Jessie in "My Son" in 2014. Played Girl in "Straight" in 2014.
How did the Federalists Papers play an essential role in the ratification of the Constitution?
The Federalist Papers played an essential role in the ratification of the constitution because they promoted its ratification to states like the New York Legislature that did not want to ratify it. It worked.
What movie and television projects has Bil Roedel been in?
Bil Roedel has: Played Dad in "Daddy for Lunch" in 2010. Played Officer Pennington in "Occasional Justice" in 2011. Played Scarecrow in "Visible" in 2013. Played Detective Cisner in "Redrum" in 2013. Played Detective Breault in "Redrum" in 2013.
Who makes a antidote for radiation fallout?
in fallout 3 there is rad away i think its the same in fallout 1 2 but i don't know i have not played them
Describe one battle in the Persian War in which the Athenians played a key role?
They played a key role by helping sparta with a better sea army in the war
Describe a conflict Adolf Hitler played?
Hitler started world war 2. then killed himseldf
What movie and television projects has Josh Matthies been in?
Josh Matthies has: Played The Billywack in "Tales from the Grave" in 2003. Played Step Dad Grape in "Food for Thought" in 2004. Played Marriage Commando in "Hugnapper" in 2010. Played Unmarried Dad in "Church Jerk" in 2010. Played Paramedic in "Visible Scars" in 2012.
What movie and television projects has Dennis Gagomiros been in?
Dennis Gagomiros has: Played DeLuca (1996) in "Beautiful Vacation" in 1996. Played Robert Peters in "Balloons, Streamers" in 1997. Played Stephen Earle in "The Ice Storm" in 1997. Played Agent Theophilos in "The Sopranos" in 1999. Played Bob in "Aaron Bacon" in 2009. Played Father in "Visible" in 2013.
