Describe the changes that take place in the iris when moving into a dark room.
The iris controls the diameter of the pupil to accommodate for the level of light that needs to enter the eye. When an individual moves into a dark room, the pupil must dilate to allow more light to enter the eye. Radial muscles in the iris contract, enabling the pupil to dilate and therefore, the eye can still see in darkness.
PT
Related Biology GCSE answers
All answers ▸Explain how a stimulus can result in a reflex reaction
Describe 2 ways in which the body prevents entry of microorganisms into the body
Tom and Lesley are married and have a child, Sally, who has Cystic Fibrosis. Lesley has just found out she is pregnant, so what is the probability that the baby will have the condition?
Define the term osmosis