RNA viruses can copy themselves which is harder for scientists to give an accurate conclusion to solve them.
Answer:
a. Biomagnification
Explanation:
Biomagnification is the name given to the progressive accumulation of substances from one trophic level to another along a food chain. Thus, the substance will have its highest concentration in individuals who occupy trophic levels furthest from producers.
For biomagnification to occur, substances must be fat soluble (lipid soluble) and thus adhere to living tissues. Another feature of substances that undergo biomagnification is that they are generally not biodegradable or metabolized by the body.
The phenomenon is quite common with heavy metals (lead; mercury) and certain chlorinated and aromatic organic compounds with higher molecular mass, such as the insecticide DDT.
Smoking ruins your lungs making it harder to breath and get oxygen
you need oxygen when you exercise so you don't faint
smokers get less so it is harder for them, its like trying to exercise while breathing through a sponge or a straw os