Answer:
They are the species which are found only in a particular area. They can be a plant, animal or microorganism. They are at great danger of becoming extinct due to the following reasons: - As they are restricted to a particular area so loss of their habitat is the major reason which could lead to extinction.
Explanation:
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.
It would show that is universe in not expanding but contracting
Population- members of one species living in a particular area
