Acid rain refers to the rain which acidic in nature having a form of precipitation and elevated levels of hydrogen ions (low pH). The normal pH of rain is around 5.6
Rising concentration of Sulfur dioxide (SO2) and nitrogen oxides (NOx) in atmosphere is one of the cause of acid rain. Sulfur dioxide (SO2) and nitrogen oxides (NOx) are released by vehicles, fossil-fuel power plants and oil refineries.
When a sulfur dioxide and nitrogen oxides released in air they mix with oxygen, water and other chemicals in the air and form sulfuric and nitric acids. sulfuric and nitric acids mix with precipitation and its pH level is about 5.2 or below.
Hence, rising concentration of SO2 And NO2x is one of the biggest reason of acid which damages agriculture, buildings and wildlife et-cetra.
There is a proper mechanism of controlling the levels of various kinds of hormones and chemicals in our body called as positive feedback and negative feedback.
In a very simple language you can understand it as whenever there is a release of a particular hormone or chemical inside the body in very huge amount then the negative feedback of the body is activated the production of that particular hormone or chemical is stopped and vice -versa for negative feedback.
Explanation:positive feedback and negative both the feedback mechanism are achieved to maintain the proper homeostasis.
Example: release of clotting factor after blood loss is a positive feedback and a hormone is released and then suddenly there is a increase in hormone b, then the amount of hormone a will decrease this is a negative feedback.
Most of the cells in the organism will have cilia or flagella - False. Kelp have flagellated gametes but not most cells.
Their life cycle includes gametophyte and sporophyte stages which involves the production of zoospores, eggs and flagellated sperm.
( Answer => D )
