Which of the following is true?

a. skeletal muscle lacks the coarse connective tissue sheaths that are found in smooth muscle.
b. skeletal muscle fibers contain sarcomeres; smooth muscle fibers do not.
c. smooth muscle lacks the thin and thick filaments characteristic of skeletal muscle.
d. skeletal muscle fibers tend to be shorter than smooth muscle fibers.

B

Skeletal muscle fibers contain sarcomeres; smooth muscle fibers do not.

Explanation:

an adaptation is a change or process by which an organism takes to be better suited for its environment. for example; migration is a behavioral adaptation, this is needed because birds are not built to last extremely cold climates. there are different adaptations because there are different species needing to adjust to different things, bears don't migrate; they hibernate.