Is a bone a cell, tissue, organ system, or whole organism

Cells tend to have a relatively small and uniform size. why aren’t cells larger?

The organelle pictured is found in cells of and is theorized to have once been an independent organism.

Which represents the cross between parent plants if one is heterozygous for yellow-colored pods and the other is homozygous for green-colored pods? yy  ´    ´    ´    ´  yy