Wht you need help on guys

What can be found in every skeletal muscle? a. nerves, bones, cartilage, and connective tissue b. tendons, cartilage, nerves, and blood vessels c. muscle fibers, nerves, connective tissue, and blood vessels d. tendons, nerves, blood vessels, and bones

How does the study of genetic disorders such as pku biologists understand normal alleles?

Me with these questions image attached