Answer:
The scientist is studying oxygen which can also be found in protien. oxygen is the element which makes up to 65% of human body mass. It is also found in proteins inside the body.
I would have to say (D.) if it's been 150 years.
There are several information's of immense importance already given in the question. Based on those information's the answer can be easily deduced.
Initial number of bacteria in the culture = 1000
Number of bacteria after t hours = 1000 (2)^t
Then
1000 (2)^t = 50000
2 ^t = 50
t = 5.6
I hope the procedure is clear enough for you to understand.
All of the above-mentioned facts are the risks that pests pose to the consumers. Pests are unwanted insects, which may infect food, as they are laden with pathogenic micro-organisms, they eat away the stored food, as a source of nourishment, and are difficult to manage. Pesticides are used to kill the, and they are chemicals, which may also pose serious threats, if consumed in large quantities.