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.
They use absolute dating methods, sometimes called numerical dating, to give rocks an actual date, or date range, ... However, there are radiometric dating methods that can be used on sedimentary rock, including luminescence dating
i hope this help
sorry if it wrong
Answer:
left ventricle
Explanation:
left ventricle pumps oxygen rich blood to the body (away from the heart, so through the arteries)
Plutchik suggested we have 8 primary emotions that combine to form secondary emotions. Putchik identified ten postulates on which his evolutionary theory of emotions is based. Plutchik's wheel of emotion illustrates the relationships between his primary emotions and other related emotions. The eight basic emotions are joy, trust, fear, surprise, sadness, anticipation, anger, and disgust.