Answer:
Basically, the Atrioventricular valves are Mitral and Tricuspid valves located between the atrium and ventricles. Their main functions is to “prevent the backflow of blood from the ventricles into the atrium during the ventricular contraction (systole).
Explanation:
Answer:
D) largest mass extinction event in Earth's history
Explanation:
The cambrian era started following the pre-cambrian extinction
The DNA has to code for a protein and it has to replicate
The answer is A. The ratio goes down as the size of the cell gets larger.
Answer:
B. the long beak helps the bird eat insects.
