Which of these cell junctions form a barrier to the passage of materials?

ANSWER :  Tight junctions form a barrier that prevents fluids from moving between cells.

The primary role of _____ is to bind animal cells together.

ANSWER :  The primary role of desmosomes (anchoring junctions) is to bind cells together.

____ aid in the coordination of the activities of adjacent animal cells

ANSWER :  Gap junctions allow for the passage of material between cells, thus facilitating 

communication between these cells.

Which of the following clues would tell you if a cell is prokaryotic or eukaryotic?

whether or not the cell is partitioned by internal membranes

whether or not the cell contains DNA

whether or not the cell carries out cellular metabolism

the presence or absence of a rigid cell wall

the presence or absence of ribosomes

ANSWER :  whether or not the cell is partitioned by internal membranes

Which of the following are common traits of chloroplasts and mitochondria?

Both are surrounded by a single membrane.

Both have their own DNA.

Both are found in plant and animal cells.

Both reproduce by meiosis.

Proteins for both are synthesized on ribosomes in the rough ER.

ANSWER :  Both have their own DNA.

Which of these cell junctions form a barrier to the passage of materials?

desmosomes (anchoring junctions)

tight junctions

keratin fibers

plasmodesmata

gap (communicating) junctions

ANSWER :  tight junctions

The primary role of _____ is to bind animal cells together.

desmosomes

gap (communicating) junctions

plasmodesmata

the cytoskeleton

tight junctions

ANSWER :  desmosomes

_____ aid in the coordination of the activities of adjacent animal cells.

Gap (communicating) junctions

Tight junctions

Desmosomes

Plasmodesmata

Keratin fibers

ANSWER :  Gap (communicating) junctions