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:
heat, density, boiling point
Hi!
Your answer is C
Which is also known as sepsis
~CoCo
Answer & explanation:
The cell was discovered in 1669 by the English scientist Robert Hooke when looking at a piece of tissue in a two-lens microscope. Hooke was able to visualize small cavities in the experiment piece, then naming such cell cavities.
Only a century and a half after the discovery of the cell, that the Cell Theory was launched, replacing the theory of spontaneous generation (or abiogenesis).
Before that, many scientists were already busy understanding the structure and functioning of the cell, generating knowledge that became fundamental to the development of biology, specifically cytology, a branch of science that studies the structure, functions and development of cells.