a control helps to increase the reliability of the results. it allows a scientist to compare it to other group(s) in an experiment. if a scientist notices a significant different btwn the control and the other groups, he can logically conclude that the independent variable has an impact on the dependent variable.
a variable is any factor, trait or condition that can exist in differing amounts or types. there are usually three tpes of variables in experiments: the independent, dependent and contolled. the independent variable variable is the one that is changed by the scientists to figure it's affect on something.
Bacteria perform important functions in the soil, decomposing organic residues from enzymes released into the soil. Each functional bacteria group plays a role in recycling soil nutrients.
your answer is C. it is temp where water vapours start to condense and forms liquid droplet from vapour condition.
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Answer:
B. retain its urine in it’s blood stream
Explanation:
Sharks are cartilaginous fishes that lives in the ocean. Oceans are always salty, hence organisms need to maintain a salt-water balance between their internal and external environment because of osmosis. Sharks are able to maintain this by ensuring that the amount of solutes in their internal environment is as much as that in their external environment.
Sharks retain a chemical contained in urine called UREA in their bloodstream to counter the osmotic effect of the salt concentration in the waters they live. This helps them maintain a concentration balance with their environment.
