Archive for the ‘education’ tag

Why do some tree leaves turn red?

By September 17th, 2013 at 11:43 am | Comment

SciStarter has a whole round-up of tree-related projects for you this season. Branch out into citizen science!

maple-tree-leaves-in-autumn-110661300185760w40

Walking around my neighborhood the other day, I was casually observing the local flora when I was struck by the redness of one particular set of leaves. While the tree pictured is not the exact one I spied upon, look at how vibrant these colors are! I began to wonder why this tree turned red while the others around it stayed orange and yellow. To begin, we must learn about why autumn leaves deviate from their greener shades in the first place.

As you probably already know, the color that most plants have is derived from chlorophyll, the yellow-green pigment found in chloroplasts responsible for allowing photosynthesis to take place. If you’ve forgotten how this process works, Crash Course Biology has a great video for this. While there are multiple forms of chlorophyll, it is generally true that most reflect green light, causing for plants to appear the way they do. (This raises the even better question of why aren’t plants black, but that deserves its own post.)

So, what happens to the chlorophyll as we approach the cooler months? When the temperature drops, deciduous plants slow the production of chlorophyll in preparation for the dormant period they will undergo during the winter. The plants will then be able to conserve energy by halting all photosynthetic processes during the lack of available sunlight. As this happens, orange and yellow carotenoids present in the leaves are exposed. These are pigments that are normally produced in leaves that help to absorb additional energy from the sun that is passed along to the chlorophyll and also to prevent auto-oxidation (basically the wear down of cells due to free radicals) from occurring. In addition to all of this, the plant begins to produce a cell wall between the stem and the leaf called an abscission layer. This will eventually cause for the leaf to be completely separated from the plant, allowing for it to fall to the ground.

Screen shot 2013-09-17 at 11.24.16 AM

Absorption spectrum of chlorophyll A & B

Okay. We’ve covered green, orange, and yellow, but what produced the scarlet beauty found above and why doesn’t it occur in all trees? The answer is anthocyanins. If you’ve ever eaten a blueberry, raspberry, pomegranate, or any other fruit that can stain your hands and clothes, you’re probably already familiar with these little molecules. These pigments are similar to the carotenoids mentioned above but serve a different purpose. In cases during the late summer when plants are beginning to slow their photosynthetic processes but there is still plenty of sunlight abound, the leaves can actually be harmed by receiving too much high-intensity light in the region of Photosystem II (photoinhibition). In order to prevent this damage, the plant begins to synthesize anthocyanins to permeate through the leaves’ surfaces. Because of its red color, the pigment absorbs a large amount of the high energy visible and ultraviolet photons striking the plant, basically acting as a “plant sunscreen.” (Check out how you can even build your own anthocyanin-based solar cell!) Additionally, anthocyanins are good indicators of plant stressors including freezing temperatures and low nutrient levels.

Next time you see a particularly red tree, make sure to think about its environment! Does it receive an abundance of light? Has it been particularly cold? Feel free to comment with links to your own pictures of vibrant trees and plants!

Just like leaves, citizen science also happens to grow on trees! Don’t believe us? Check out our tree projects round-up!

References:

Why do leaves change color and turn red?

Carotenoid-to-chlorophyll energy transfer

Understanding Vegetation and Its Reflectance Properties

Winter Adaptations of Trees

Photo: Public Domain Pictures, Wikipedia


This was a guest post by Joe Diaz, a science educator and enthusiast. Follow @RealJoeDiaz. View the original post.

Know your numbers

By January 14th, 2013 at 7:44 am | Comment

Do you know your numbers?

Do you just “get” numbers? Or have they always left you a little baffled? Now you can test this observation and quantify your number sense.

Number sense is our “gut knowledge” of numbers’ magnitude, their relationships, and even basic arithmetic. Number sense is thought to be innate, potently present as early as infancy. But while we all have it, we are not made equal. Individuals vary in the accuracy of their number sense. In other words, some people are better at guessing than others. Scientists think that such differences could relate to an individual’s mathematical aptitude.

To explore this further, researchers at John Hopkins University developed a number discrimination test, available for free online. The 10 minute test is straightforward. Yellow and blue dots flash onto a screen and you have to guess if there were more yellow or blue dots. After, the program provides a report of your performance and a comparison to others in your demographic.

Already researchers around the world have used this tool to explore different aspects of and factors relating to number sense. The John Hopkins developers have also created a package for educators that includes instructions for administering the test and guides for data analysis.

Curious to learn more? Test yourself!

Photo: USAF

Announcing the SciStarter kiosk interface for schools, museums and public areas.

By December 13th, 2012 at 5:21 pm | Comment

SciStarter Kiosk

Earlier today, the North Carolina Museum of Natural Sciences hosted “E.O. Wilson’s Global Town Hall,” with biologist Edward Osborne Wilson, University Research Professor Emeritus at Harvard. In anticipation of this exciting event, the museum revamped its Citizen Science Center and added new features.

“I am especially pleased that we now offer a SciStarter kiosk in our exhibit as it will provide museum visitors access to hundreds of citizen science projects with a few clicks of the mouse,” said Chris Goforth, manager of Citizen Science at the Museum and the brains behind one of our favorite citizen science projects, the Dragonfly Swarm!
“SciStarter has an unparalleled ability to match the public with citizen science projects, regardless of their interests, and does a great job of highlighting how anyone, anywhere can become a citizen scientist. It is a most welcome addition to our citizen science exhibit.”

The SciStarter kiosk is designed to prevent random web surfing while enabling visitors to “shop” for their favorite citizen science projects from among the more than 500 curated projects featured in the SciStarter Project Finder. Visitors can simply email their “shopping cart” to themselves so they can get get started later!

If you would the SciStarter Kiosk interface in your school, science center or other public area, please email info@scistarter.com to learn more.

BioBlitz: Explore the National Parks with National Geographic

By August 22nd, 2012 at 12:39 pm | Comment 1

Attention all backyard explorers and rosebush whackers: this is the opportunity you’ve been waiting for. Your days of leading patient parents on perilous neighborhood expeditions are over. Put down that “machete.” Stop mushing the dog. Grab your merit badges. The big leagues are calling, and they want you on their next adventure!
This Friday, August 24, the National Park Service and the National Geographic Society will host their annual BioBlitz species count at Rocky Mountain National Park in Colorado. Hundreds of students and thousands of local citizens will join about 200 scientists, naturalists, and explorers from around the country to collect and analyze wildlife data, transforming the forest into a massive outdoor classroom alive with curiosity and discovery.
“I am always moved by the commitment of the National Parks Service to protecting our country’s ecological diversity and sharing it with the general public,” said Daniel Edelson, Vice President for Education at National Geographic. “The BioBlitzes are…explicit strategies for preparing young people to care for their world.”
National Geographic has been “inspiring people to care about the planet” through its magazine since 1888, but it is relatively new to the business of “preparing” them to do so. With the rapid proliferation of digital media, the society saw an opportunity to provide teachers and students with the resources to learn (curricula, films, games) and the tools to take action, thus engaging with their audience in ways never thought possible. Can’t make it to Colorado to catch bugs, spot birds, and count elk on Friday? You can take part in the action via their Google Hangout starting at 3 PM (EST), or even plan your own BioBlitz by following their instructions.
“It’s exciting to see that other people are embracing the concept and using the resources we developed to conduct their own biodiversity research in their own parks in their own communities,” said Sean O’Connor, a BioBlitz project manager.
This year’s BioBlitz, the sixth in a series of ten leading up to the National Park Service’s Centennial in 2016, comes amidst the strain of another round of federal budget cuts and continued lack of funding for the program. As the National Park Service prepares to face the challenges–political, economic, environmental, or otherwise–ahead, National Geographic aims to show its next generation of steward why its 397 park encompassing ver 84 million acres of land are worth preserving.
“We believe [the most important lesson] we can teach young people is how interconnected our world is,” said Edelson. “Even in our most pristine National Parks, you can’t escape the impact of human activities on the natural environment. A BioBlitz is a chance for young people to see those impacts and learn about the connections between their own actions and the health of ecosystems.”

Attention all backyard explorers and rosebush whackers: this is the opportunity you’ve been waiting for. Your days of leading patient parents on perilous neighborhood expeditions are over. Put down that “machete.” Stop mushing the dog. Grab your merit badges. Adventure is calling!

This Friday, August 24, the National Park Service and the National Geographic Society will host their annual BioBlitz species count at Rocky Mountain National Park in Colorado. Hundreds of students and thousands of local citizens will join about 200 scientists, naturalists, and explorers from around the country to collect and analyze wildlife data, transforming the forest into a massive outdoor classroom alive with curiosity and discovery.

“I am always moved by the commitment of the National Parks Service to protecting our country’s ecological diversity and sharing it with the general public,” said Daniel Edelson, Vice President for Education at National Geographic. “The BioBlitzes are…explicit strategies for preparing young people to care for their world.”

National Geographic has been “inspiring people to care about the planet” through its magazine since 1888, but it is relatively new to the business of “preparing” them to do so. With the rapid proliferation of digital media, the society saw an opportunity to provide teachers and students with the resources to learn (curricula, films, games) and the tools to take action through a more robust educational initiative, thus engaging with their audience in ways never thought possible. Can’t make it to Colorado to catch bugs, spot birds, and count elk on Friday? You can take part in the action via their Google Hangout starting at 3 PM (EST), or even plan your own BioBlitz by following their instructions.

“It’s exciting to see that other people are embracing the concept and using the resources we developed to conduct their own biodiversity research in their own parks in their own communities,” said Sean O’Connor, a BioBlitz project manager.

This year’s BioBlitz, the sixth in a series of ten leading up to the National Park Service’s Centennial in 2016, comes amidst the strain of another round of federal budget cuts and continued lack of funding for the program. As the National Park Service prepares to face the challenges ahead—political, economic, environmental, or otherwise—National Geographic aims to show its next generation of stewards why its 397 parks encompassing ver 84 million acres of land are worth preserving.

“We believe [the most important lesson] we can teach young people is how interconnected our world is,” said Edelson. “Even in our most pristine National Parks, you can’t escape the impact of human activities on the natural environment. A BioBlitz is a chance for young people to see those impacts and learn about the connections between their own actions and the health of ecosystems.”

10 back-to-school projects for young citizen scientists

By September 13th, 2011 at 12:09 pm | Comment 1

World Water Monitoring Day - San Juan, Puerto Rico

World Water Monitoring Day is one of many citizen science projects for primary and secondary school students.

As summer comes to a close, a young person’s fancy may turn to fretting at the thought of being cooped up in a classroom. But for fans of science and nature—and by that we mean kids who like to watch clouds, hunt mushrooms, prowl around graveyards, and check out what gets squashed on the side of the road—fall need not signal the end of fun.

To keep young minds entertained as well as enlightened, we recommend the following 10 back-to-school projects for student citizen scientists. Teachers and parents, please note: Many of these programs provide materials around which you can build lessons. And there are lots more where these came from.  Visit our Project Finder for a full list of citizen science projects for primary and secondary school students.

World Water Monitoring Day: World Water Monitoring Day is an international program that encourages citizen volunteers to monitor their local water bodies. An easy-to-use test kit enables everyone from children to adults to sample local water bodies for basic water quality parameters: temperature, acidity (pH), clarity (turbidity), and dissolved oxygen. Though World Water Monitoring Day is officially celebrated on September 18, the monitoring window is extended to cover the period from March 22 (World Water Day) until December 31. Check out what one of our members said about the project.

School of Ants: Join North Carolina State University researchers in a citizen-scientist driven study of the ants that live in urban areas, particularly around homes and schools. Collection kits are available to anyone interested in participating. Teachers, students, parents, kids, junior-scientists, senior citizens and enthusiasts of all stripes are involved in collecting ants in schoolyards and backyards using a standardized protocol so that project coordinators can make detailed maps of the wildlife that lives just outside their doorsteps.

The Albedo Project: Wherever you are – anywhere in the world – on September 23th, contribute to science by taking a photo of a blank white piece of paper, outside in the sun, between 4:00 and 7:00 pm local time. Your photo will used to to help students measure how much of the sun’s energy is reflected back from the Earth — our planet’s “albedo.” It’s one way scientists can monitor how much energy – and heat – is being absorbed by our planet.

Students’ Cloud Observations On-Line (S’COOL): Report your observations of clouds—their shapes, height, coverage, and related conditions—so that NASA scientists can compare them with data from weather satellites passing over your area. Tutorials and observing guides are available for students. For teachers, the program provides lesson plans, charts, and advice on related educational standards.

Tracking Climate in Your Backyard: This project teaches volunteer meteorologists aged 8 to 12 about the scientific process by enlisting them in the collection of weather data in their communities. Download free support material and curriculum.

Physics Songs:  Physics Songs aims to be the world’s premier website devoted to collecting and organizing all songs about physics. It is managed by Walter F. Smith, Professor of Physics at Haverford College. Songs about physics can help students to remember critical concepts and formulas, but perhaps more importantly they communicate the lesson that physics can be fun.

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