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; digestive
c) respiratory; circulatory

Imagine you are introducing the lac operan and the trp operon to students who have never learned about it before. complete the table to compare the similarities and differences between the two operons

How does the carbon cycle involve an exchange of carbon

20 point pls brianliest 1. what does a red shift mean? blue shift? 2. describe the big bang theory. according to this theory, how old is the universe? 3. scientists believe the universe is expanding. what is the evidence that supports this? 4. describe a nebula. 5. describe the 3 types of galaxies. what is a barred spiral galaxy? 6. what is a light year? how far is alpha centauri from earth? 7. describe the universal law of gravitation. be sure to include gravitational force between two objects. 8. describe the planets’ orbits around the sun. 9. what is the asteroid belt? where is it located? 10. describe rotation and revolution of earth. what determines an earth day and year? 11. how do galaxies exist? 12. compare and contrast the inner and outer planets. 13. what causes the seasons?