Answer:
When a molecule moves down its concentration gradient is it participating in passive transport; moving up the concentration gradient requires energy making it Answer:active transport
Answer:
Wheezing happens when the airways are tightened, blocked, or inflamed, making a person's breathing sound like whistling or squeaking. Common causes include a cold, asthma, allergies, or more serious conditions, such as chronic obstructive pulmonary disease (COPD).
Explanation:
C. an endangered species is one that is at risk of dying out, while an extinct species is one that no longer exists.