The answer is; UV (ultraviolet)
The security pens use UV light to illuminate some marking on an object,such as a watermark, to identify its authenticity or owner. The markings are usually invisible to the naked eye under visible light. The marks are only visible when illuminated with UV light. This is because the marking is made of a fluorescent material that absorbs light of a shorter wavelength (this case UV) and emits a longer wavelength (this case visible light).
Answer: On topographic maps, elevation is shown by using contour lines. The difference in elevation between one contour line and the next is called the contour interval. The contour interval is selected based on the relief of the area being mapped. Every fifth contour line is darker than the four lines one either side of it.
Explanation:
Answer:
Animal migration is the relatively long-distance movement of individual animals, usually on a seasonal basis. It is the most common form of migration in ecology. It is found in all major animal groups, including birds, mammals, fish, reptiles, Many of these migrations are north-south, with species feeding and breeding in.
Answer:
Explanation:
Without the presence of decomposers and detritivores in a forest ecosystem organic material would not break down and the nutrients would no longer be available to other organisms. Moreover, dead plants and animals will pile up. Because, detritivores eat fragments of dead matter in an ecosystem and decomposers break down dead organisms so the environment will no longer be clean.
