Most of the exchange surfaces of multicellular animals are lined with

Most of the exchange surfaces of multicellular animals are lined with

A) connective tissue.
B) smooth muscle cells.
C) neural tissue.
D) epithelial tissue.
E) adipose tissue.




Answer: D

The absorptive epithelia in the gut are considered "polarized" because

The absorptive epithelia in the gut are considered "polarized" because

A) thick and thin filaments are present.
B) they pump wastes into the lumen while pumping nutrients toward the blood.
C) the colors seen on the top and bottom of the cells are different.
D) they must fire action potentials to absorb most nutrients.
E) the structures on the apical surface are different than those on the basal surface.

Answer: E

Of the following choices, the epithelium with the shortest diffusion distance is

Of the following choices, the epithelium with the shortest diffusion distance is

A) simple squamous epithelium.
B) simple cuboidal epithelium.
C) simple columnar epithelium.
D) pseudostratified ciliated columnar epithelium.
E) stratified squamous epithelium.

Answer: A

An exchange surface in direct contact with the external environment is found in the

An exchange surface in direct contact with the external environment is found in the

A) lungs.
B) skeletal muscles.
C) liver.
D) heart.
E) brain.




Answer: A

Tissues are composed of cells, and tissues functioning together make up

Tissues are composed of cells, and tissues functioning together make up

A) organs.
B) membranes.
C) organ systems.
D) organelles.
E) organisms.

Answer: A

Multicellular organisms must keep their cells awash in an "internal pond" because

Multicellular organisms must keep their cells awash in an "internal pond" because

A) their membranes will crystallize if not in contact with interstitial fluid.
B) an aqueous medium is needed for the cellular exchange of nutrients, gases, and wastes.
C) this prevents the loss of water due to osmosis.
D) their cells need to be protected from dissolved nitrogen gas in the blood.
E) terrestrial organisms have not adapted to life in dry environments.

Answer: B