Question

Which of the following statements are false?
(I) Light is essential for life to exist on the earth.
(II) Many species of the small plants under the canopy to tall trees in the forest show optimal use of available light due to having large-sized antenna molecules and a higher number of thylakoids.
(III) UV-rays are not harmful to many organisms.
(IV) Photoperiodic requirement is not essential for many plants for flowering
(V) The sun is the source of light and temperature.
(VI) Red algae can live in the deeper water of the sea because of having pigment phycoerythrin.

Answer 1

Hint: Overexposure to UV-B radiation can result in skin cancer and sunburn. Humans may experience acute and chronic health consequences on their skin, eyes, and immune systems as a result of extended exposure to solar UV radiation.

Complete Step by Step Answer:
The sun and artificial sources, such as tanning beds, both emit ultraviolet (UV) radiation, a type of non-ionizing radiation. Even though the rays are known to help humans in some ways, such as by producing vitamin D, there are also potential health hazards. UV radiations are naturally produced by the sun, as opposed to tanning beds, some halogen, fluorescent, and incandescent lights, as well as mercury vapour lighting, which is frequently found in stadiums and school gyms. Some types of lasers produce ultraviolet photons artificially. UV light exposure can hasten the ageing process of the skin and lead to indications of sun damage such as actinic keratosis, wrinkles, leathery skin, liver spots, and solar elastosis.

Additionally, UV rays might harm your eyes. They have the potential to burn or inflame the cornea, which is located in the front of the eye. Based on their wavelengths, UV radiation is divided into three main categories: ultraviolet A (UVA), ultraviolet B (UVB), and ultraviolet C (UVC). Though some UVB radiation does reach the earth, the majority of UV energy that does is UVA. Both UVA and UVB radiation can have a negative impact on health, although UVA has a deeper penetration rate and is more consistent year-round. The most harmful kind of UV radiation is short-wavelength UVC. Additionally, UV-C can have negative effects that range from being carcinogenic to mutagenic.
The atmosphere entirely filters it out before it can reach the surface of the earth. Although medium-wavelength UVB is very biologically active, it cannot pass through deeper skin layers.UV radiation overexposure can cause major health problems, including cancer. The most prevalent type of cancer is skin cancer in the United States.

Hence, option (III) UV-rays are not harmful to many organisms is the correct option


Note:Detailed information about the types of UV rays and the harm caused by them is necessary to be able to solve this question.