Question

a scientist is comparing the outer structure of an onion cell, structure x, to the outer structure of a human skin cell, structure y. which generalization is true about the types of structures being examined? structure x is not living, and structure y is living. structure x can be found in some human cells, and structure y can be found in some plant cells. structure x is only found in plant cells, and structure y is found in plant and animal cells. structure x is semipermeable, and structure y is selectively permeable.

Explanation:

An onion cell is a plant cell. Its outer - structure (cell wall) is only found in plant cells. A human skin cell is an animal cell. Its outer - structure (cell membrane) is found in both plant and animal cells.

Answer:

Structure X is only found in plant cells, and structure Y is found in plant and animal cells.