Question

Identify the wrong statement with reference to UV rays.

• A. UV-A is more harmful to animals than UV-B.
• B. UV radiation falls in the range between 100-300 nm wavelength.
• C. UV radiation is classified into three categories.
• D. UV radiation kills microorganisms.

Answer 1

The correct option is A UV-A is more harmful to animals than UV-B.

• The UV region covers the wavelength range 100-400 nm and is divided into three bands: UVA (315-400 nm) UVB (280-315 nm)
• The most common form of UV radiation is sunlight, which produces three main types of UV rays: UVA, UVB, UVC.
• At certain wavelengths, UV is mutagenic to bacteria, viruses and other microorganisms. Particularly at wavelengths around 260–270 nm, UV breaks molecular bonds within microorganismal DNA, producing thymine dimers that can kill or disable the organisms.
• UVB, the chief cause of skin reddening and sunburn, tends to damage the skin's more superficial epidermal layers. It plays a key role in the development of skin cancer and a contributory role in tanning and photoaging.

So, the correct answer is 'UV-A is more harmful to animals than UV-B.'.