<span>Error bars within treatments illustrate confidence intervals, standard errors, standard deviations or other quantities. However, different types of error bars exist, so figure legends must be sure to distinguish which error bar is being represented. </span>
If it has valves then it is a vein.
The respiratory and circulatory systems bring oxygen and nutrients to the cells. The respiratory and circulatory systems work together to maintain homeostasis. The respiratory system moves gases into and out of the blood.
<span>Organic Chemistry is so important in the study of Biology because most reactions in Biology are organic reactions. Organic chemistry is the study of structure, properties, and reactions of organic compounds</span>
