Answer:
Alveoli - tiny sacs within the lungs that exchange oxygen and carbon dioxide with the body's blood
Eukaryote - a cell that has a membrane-bound nucleus and/or organelles as its major characteristic.
Pathogen - a disease-causing agent
Phloem - vascular tissue tubes in plants that transport food and nutrients
Prokaryote - a cell whose nucleus is not bound by a membrane
Xylem - vascular tissue tubes in plants that transport water and minerals
Explanation: