B.sections in the chromosomes
C.the nucleotides with either a substitution, deletion or insertion
D.one or a few nucleotides in the RNA
b. mutualism
c. cooperative symbiosis
d. cooperation
Answer:
many alveoli are present in the lungs with a shape that further increases surface area. Thin walls - alveolar walls are one cell thick providing gases with a short diffusion distance. Moist walls - gases dissolve in the moisture helping them to pass across the gas exchange surface.
Explanation: