Influenza (also known as flu) is a contagious respiratory illness caused by flu viruses. It can cause mild to severe illness, and at times can lead to death. Flu is different from a cold. Flu usually comes on suddenly.
B, because it's not an advantage for something to be expensive and time consuming
Answer:
Mitochondrial DNA is circular, so it doesn't shorten when it replicates unlike the rest.
The correct answer is: <span>oxygen is used up as algae is decomposed, reducing the amount available to other organisms. Algae require nutrients to grow, and it is well known that in many rivers, algal growth is limited by one particular nutrient, most often phosphates or nitrates. This means, as soon as there is a sizable input of nutrients into a river or lake, the algae population will grow exponentially. This dramatically changes the trophic status of a river or lake. However, the algal population will eventually exhaust the supply of nutrients, and the vast biomass of algae that grew over a short period of time will all die at the same time due to lack of nutrients. As you know, rotting organic matter uses up oxygen. This results in an anoxic aquatic environment that can kill all the other organisms living in that environment. </span>
