We are the cause of climate change. It is also caused by biotic factors such as variations in solar radiation received by Earth, plate tectonics, and volcanic eruptions.
I think the enzyme photolyase is activated by light and can repair thymine dimers caused by UV radiation. Exposure to UV radiation is the main factor that causes skin cells to become cancer cells. These enzymes are involved in the repair of ultraviolet light-induced DNA damage when activated by light absorption.
You are testing for the presence of starch: Iodine dissolved in an aqueous solution of potassium iodide - reacts with starch producing a deep blue-black color. This reaction is the result of the formation of polyiodide chains from the reaction of starch and iodine.
The pH will decrease because lemon juice is very acidic meaning it would bring the pH level down to a more acidic value.
In Science, a electron in an atom is always negative. The more electrons you have, the more negative a atom is. The more protons (Positives) you have, the more positive a atom is. To balance an atom out, have the same amount of Electrons and Protons.