Four general conditions necessary for natural selection to occur<span> are: A. More organisms are born than can survive. B. Organisms vary in their characteristics, even within a species. D. Differences in reproduction and survival are due to variation among organisms.</span>
<span>The process whereby neutrophils and other white blood cells are attracted to an inflammatory site is called as <u>chemotaxis</u>. It is a process by which inflammatory cells migrated or attracted towards other cells in the blood. It's like a phenomena of negative cells attracted to positive cells. Technically speaking, it's a movement of cells in response to chemical cells. It's an important response common in cellular biology. It's also a process by which cells translate chemical information.</span>
Answer:
cell > tissue> organ> system
Explanation:
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.
