Question

Contractile proteins are not found in_____________.

• A. Bones
• B. Blood
• C. Cartilage
• D. All of the above

Answer 1

The correct option is D All of the above

Muscle cells are composed of muscle fibers or myocytes. They contain specific proteins called contractile proteins that help in muscle contraction.

Bone cells are embedded in the hard matrix, which is made up of salts of calcium and phosphate. Bones do not perform contraction as a function. Therefore, contractile proteins are not present in bone.
Blood is a type of connective tissue in which red blood cells, white blood cells, and platelets are suspended in the fluid matrix containing proteins, salts, and hormones. As it does not perform contractile function, contractile proteins are absent.
Cartilage is a type of connective tissue having widely spaced cells, which are interspersed in a matrix made of proteins and sugars. At some places like ear pinna, cartilage can fold but it does not contract and relax. Hence, such proteins are absent in cartilage.

Hence the correct option is D.