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>
Answer: mitochondrion
explanation: The enzymatic reactions of cellular respiration begin in the cytoplasm, but most of the reactions occur in the mitochondria. Cellular respiration occurs in the double-membrane organelle called the mitochondrion. The folds in the inner membrane are called cristae.
The answer is spicules. These
sharp-pointed structures are formed from calcium carbonate skeleton of
the organisms. They can also be formed from silica. They can be big (megascleres),
or microscopic (microscleres). Also dependent on the number of axis on the spicules, they are classified as monoaxon,
triaxon or polyaxon.
I believe this would be true