There are about 4 million red blood cells (RBCs) in a microliter of human blood. An adult human
has around 5 liters of blood in their body. Based
on these numbers, roughly how many red blood
cells are in the body in scientific notation?

increases the risk of extinction 

explanation:

the answer is that if the species suffers from the disease, there is nothing stronger than the others, so it is possible to remove wholeness. an example of this is hunger in irish potatoes, which has a deadly disease bearish part of all potato harvest masses. pretty much ruins the land of crops.