Answer:
protons..................
I disagree it should be A
Answer:
Open circulatory system:
Relies on the heart to keep blood flowing
Used in all vertebrates
Sorry thats all i know :)
When you swallow food, it doesn't just drop down into your stomach. Muscles contract in a wave-like motion to move the food along through the esophagus. This muscle movement is called, peristalsis, or peristaltic waves. These peristaltic waves contract behind the food bolus pushing it along the digestive tract.
Answer:
the number of chromosome sets found in the nucleus
Explanation:
