There are two classes of membrane transport proteins—carriers<span> and </span>channels<span>. Both form continuous </span>protein<span> pathways across the lipid bilayer. Whereas transport by </span>carriers<span> can be either active or passive, solute flow through </span>channel proteins<span> is always passive.</span>
<span>The lymphoid tissues of the intestinal tract are collectively referred to as GALT.Gut-associated lymphoid tissue (GALT) is a component of the mucosa-associated lymphoid tissue (MALT) which works in the immune system to protect the body from invasion in the gut.</span>
B. Clade 1 is ancestral to all the other clades
