Which of the following statements about the cytoskeleton is correct? choose all that apply.
a. the cytoskeleton is made of a mixture of protein and carbohydrate.
b. the cytoskeleton provides shape and support to eukaryotic cells, particularly animal cells.
c. cytoskeletal elements can be found in the cytoplasm and in at least one organelle.
d. the cytoskeleton forms the cell wall of plant cells.
e. cytoskeletal elements are rigid, and once established are not easily changed.
f. the cytoskeleton is made of a mixture of protein and lipid.