On the dorsal surface of the heart are the stumps of two relatively large but thin-walled blood vessels that enter the right atrium. They are connected, and you would be able to pass a slender probe continuously through them. The upper vessel is the superior vena cava, and the lower one is the inferior vena cava. 6. Observe the inside of the right atrium. What do you notice

Compare and contrast nutrient limitation in soil vs. nutrient limitation in aquatic ecosystems

The pharynx is the structure in the body that serves as a pathway of both air and food. how does the body make sure that food does not get into the lungs? the salivary glands secrete enzymes that pull food out of the air pathway. the small intestine pushes the air out of the digestive system. the pancreas breaks down food in the air pathway. the epiglottis closes the air pathway so that food will not enter it.

Why is the theory of evolution important? it disproves all other theories about how life began. it provides a topic for debate. it is a unifying concept in biology. it explains how life began. i know for sure, it is not "it is a unifying concept in biology."