The first one:He may be introducing an invasive species into the ecosystem that may damage it greatly
1) The antibodies destroy the antigen (pathogen) which is then swallowed and digested by macrophages.
2) White blood cells can produce antitoxins which destroy the toxins that are otherwise known as poison.
Carbohydrates= Saccharides or simple sugars
Protein= Amino Acid
Explanation : x = 79 marks
The marks scored by Mike on four math test are 88,91,75 and 72.
Average of marks, A = 81
Let in fifth test he scores x marks.
The formula for finding average is :




In the fifth test he scores 79 marks.
Hence, this is the required solution.