Explanation:
energy flows in only one direction through an ecosystem.
Answer:
A is the correct answer.
Explanation:
Because Adaption means to the process by which a species becomes fitted to its environment. So A is the closest.
Answer:
pfu/ml
Explanation:
Given -
Bacteriophage dilution
ml
Volume of bacteria and plate with top agar
ml
Number of plaques
pfu
Dilution (d) 
Final concentration of phage stock is equal to

Where pfu is the count of plaques
d is the dilution and v is the volume
Substituting the given values, we get -
pfu/ml
C)Unicellular, <span>maybe microorganisms but this is misleading because not all unicellular organisms are microscopic.</span>