Answer:
1-A ring-shaped muscle that relaxes or tightens to open or close a passage or opening in the body.
2-Sphincters are specialized muscles that are located at the upper esophagus (upper esophageal sphincter (UES) and the gastroesophageal junction
Explanation:
Answer:
C
Explanation:
Because more bulbs are add the dimmer they get
Answer: Blood vessels
Explanation: Blood vessels consist of veins, venules, arteries, arterioles and capillaries that absorbs nutrients and minerals from organs and transport them to tissues and cells. It also transport oxygen and carbon dioxide to and from the heart to the lungs.
Therefore blood vessels are found in almost every organ, tissue and cells in the body to deliver nutrients, remove waste and filter lymph as part of immune system.
<span>B. A prokaryotic cell does not have nucleus and the other one does. The most defining characteristic of eukaryotic cells is their true nucleus. Prokaryotes lack true nucleus</span> and membrane bound organelles.
Answer:
endothermic is the right answer
