What is the function of each lymph organ?
organ in which macrophages
break down old blood cells and
bacteria or viruses
organ where lymphocytes are
synthesized, developed,
and matured
organ that acts as the first line of
defense in the nasal and oral cavity
organ where a special lymphocyle
that aids the immune system
is activated
spleen
thymus
red bone marrow

The images show two species of tree frogs in a particular region. the gray tree frogs are adapted to the trees of the woodlands, while the green tree frogs can survive in woodlands or grasslands. the gray frog was abundant in the woodlands. because of climatic changes, most of the trees in the region died, and the woodlands changed to grasslands. in such a case, the . the gray tree frog is closely related to the green tree frog genetically, but they have different mating calls. this suggests that speciation occurred because of .