|
|
On average, the stomach produces 2 L of hydrochloric acid per day.
Bacteria have flourished on the earth for over three billion years. They were the first life forms on the planet.
Pope Sylvester II tried to introduce Arabic numbers into Europe between the years 999 and 1003, but their use did not catch on for a few more centuries, and Roman numerals continued to be the primary number system.
When blood is deoxygenated and flowing back to the heart through the veins, it is dark reddish-blue in color. Blood in the arteries that is oxygenated and flowing out to the body is bright red. Whereas arterial blood comes out in spurts, venous blood flows.
A recent study has found that following a diet rich in berries may slow down the aging process of the brain. This diet apparently helps to keep dopamine levels much higher than are seen in normal individuals who do not eat berries as a regular part of their diet as they enter their later years.
![reactions of an ester with a carboxylate group to form an anhydride. The R group is the same in each](https://biology-forums.com/gallery/47/medium_9828_12_01_13_11_17_43.jpeg)
![The monthly changes of angle between the direction of illumination by the Sun and viewing from Earth](https://biology-forums.com/gallery/47/medium_12359_23_01_13_7_07_24.jpeg)