Asthma narrows airways to the lungs and in the lungs by contraction of muscles around the air passages, swelling of the airway lining, and build-up of excessive mucus. because of this, asthma makes both the and systems work harder to deliver oxygen to the cells throughout the body. a) respiratory; nervous b) respiratory; muscular c) respiratory; digestive d) respiratory; circulatory

What are the four basic classes of organic molecules how do they differ structurally and functionally

Hemoglobin is a proton that carries oxygen around your body what is hemoglobin made from

The embryos of a bird, a reptile, and a mammal are similar in appearance. how does comparing the physical appearance of embryos of different species support the theory of evolution? a. it shows that these organisms share a common ancestor. b. it provides evidence that these organisms eat the same foods. c. it shows that these organisms share the same habitat. d. it provides evidence that these organisms suffered a genetic mutation.