A Little Bit More
Until humans learned that ultraviolet light even existed, they had no idea that other animals might be able to see a world differently than we do. Today we know that many kinds of plants use ultraviolet light to help insects find their nectar/pollen and facilitate pollination. Nectar guides provide a high-contrast zone that attracts pollinators to them like “airport runway lights for aircraft”. Nectar guides are also referred to as “honey guides” or “pollen guides” so don’t let this confuse you; all three refer to the same thing.
these Black-eyed Susans don't look like this to hungry bees
Those flowers that are bee-pollinated are especially likely to use nectar guides for attraction but other insects, like butterflies, are able to key in on ultraviolet light too. As you might guess, nectar guides both help insects find a food source as well as help a plant insure its pollination.
Although humans can not see ultraviolet light without artificial visual aids, many of us are well aware of its affects – ultraviolet light is what can cause us to have a sunburn.
Activities
Science – Secret Messages
Objectives: Better understand visual importance of light and color
Materials: http://ww23.rr.com/index.php?origURL=http://www.optics.nasa.gov/docs.html
This NASA exercise won’t allow you to see ultraviolet light but it will demonstrate how color and light can be very important to how we “see” our world. This activity will require more teacher involvement with younger students but all students can view and learn from this activity.
This is NOT the same principle as our unit discusses about nectar guides but it is a visual exercise – our vision does not depend on what is available, but on what we’re able to “perceive” for ourselves!
Check out this website and go to page #45 for an activity on: Light and Color – Hidden Messages at: ww23.rr.com
Key Concepts
Structures and Functions, Reproduction, Adaptations and Diversity
Questions
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