Answer:
Option A, pathogen A
Explanation:
ID50 is a way to measure the virulent efficiency of a pathogen. ID50 for a pathogen depicts the number of pathogens required to infect or cause the associated disease with in 50 percent of any population sample.
This means that 50 pathogens A can infect 50 percent of any sample population.
While 1000 pathogen B and 1000000 pathogen C are required to infect 50 percent of any sample population.
hence, Most virulent pathogen is Pathogen A
C the content is current but It might be D
Answer:
4.54 billon years
Explanation:
the earliest time that life forms first appeared on Earth is at least 3.77 billion years ago possibly as early as 4.28 billion years
