answer:

1. Waves have many uses which are vital to our daily lives such as visible light- it allows us to see; microwaves and radio waves- they allow for us to communicate faster via mobile phones, television and radio; infra-red waves- they are used in night-vision cameras and in many remote controls; and x-rays- are used in medical imaging purposes.

2. Waves can also have some harmful effects such as gamma rays and x-rays. They can damage DNA and can cause cancer after long exposure to gamma rays and x-rays; Ultra Violet light- it can cause sunburn andeven skin cancer; and lasers- it can blind or burn if used incorrectly.

source: Cameron, G., 2015