Plants use direct environmental stimuli for orientation in growth and movement. This is called tropism. The responses of the plant may be toward (positive) or away (negative) from the external stimulus or stimuli.Click the links below to learn more about the different types of stimuli and the plants reaction to it:Phototropism-Reaction to light and different wavelengths.his is called tropism. The responses of the plant may be toward (positive) or away (negative) from the external stimulus or stimuli. Click the links below to learn more about the different types of stimuli and the plants reaction to it:
I'm thinking about training for a marathon. A marathon is 26.2 miles or 42 kilometers. Although some marathons differ in their terrain (some are very flat, some are extremely hilly) and degree of difficulty, the distance is always 26.2 miles.
Recreational runners tend to concentrate on either relatively short races, such as 5K and 10K, or get hooked on the marathon. In between, there are the longer endurance distances of the half-marathon (13.1 miles) and the 20K (12.4 miles).