Answer:
That is administered and controlled
Step-by-step explanation:
A variable is the condition or a product that may vary without the influence of any investigator. Such variables can be found abundantly in our daily lives, ranging from air to sunlight. Controlling such variables ensures the limitation of their influence on the outcome of an experiment. In connection to this experiment, the variables that are controlled are the mineral content in the water, the amount of bacteria food, the amount of light and the the constant temperature of 20 degrees C.
If not administered or these variables controlled, the experiment would not clearly explain the impact of caffeine on the heart beat of the water fleas as other variables may have influenced it. Thus variables are controlled to study the singular impact of any agent or effect.
Answer:
a,the ability to go from a single cell to multicellular organism
.dont taste or sniff chemical
Tasting and smelling some chemicals can be dangerous and even deadly.the best way to know what is in a container is to label
. Don't play mad scientists
This result in mixing chemcals to see what happens the result could be explosion ,fires,or releasing toxic chemicals
.Dress for the lab
This is a safety rule because clothing is one of your best form of protection against an accident wear covered shoes,long pants,and keep your hair tied so it cant fall into your experiment