Ultraviolet waves are primarily responsible for which of the following?

Ultraviolet waves are primarily associated with causing suntans and sunburns due to their interaction with the skin. When the skin is exposed to ultraviolet radiation from the sun, it stimulates the production of melanin, which leads to tanning as a protective response against further UV damage. However, excessive exposure can result in sunburn, which is characterized by inflammation and damage to the skin cells. This effect is a direct result of UV waves penetrating the skin and affecting cellular structures, highlighting their biological significance in both skin pigmentation and potential harm.

Other choices, while related to various forms of energy or radiation, do not align with the specific effects of ultraviolet waves. For instance, while heat from the sun provides warmth, it is primarily due to infrared radiation. Electromagnetic communication involves different frequencies of electromagnetic waves, such as radio or microwave radiation, rather than ultraviolet waves. Cooking food typically relies on the thermal energy generated by microwaves or infrared radiation, which also differs from the role of ultraviolet waves. Thus, the unique properties and effects of ultraviolet radiation clearly establish its primary responsibility for causing suntans and sunburns.