Question

Contractile proteins are found in

• A. Bones
• B. Blood
• C. Muscle
• D. Cartilage

Answer 1

The correct option is C

Muscle

The correct option is C.

Explanation for the correct option:

1. Muscles are of three types (i) skeletal (ii) visceral and (iii) cardiac.
2. Skeletal muscles are made of a number of muscle bundles.
3. A number of muscle fibers are present inside the muscle bundle.
4. A distinguishing feature of the muscle fiber is the presence of a large number of parallelly arranged filaments called myofilaments or myofibrils.
5. Each myofibril has alternate dark and light bands on it.
6. I-band or Isotropic bands are called light bands and contain actin filament.
7. A’ or anisotropic band contains myosin and are dark bands.
8. Actin and myosin are contractile proteins responsible for contraction.

Explanation for the incorrect options:

Option A

1. Bones are the connective tissue
2. Bones are hard and non-pliable.
3. They are rich in calcium salts and collagen fibers which give bone its strength.
4. It is the major tissue that provides structural support to the body.

Option B

1. Blood is a fluid connective tissue
2. Red blood cells, white blood cells, platelets, and plasma are present in the blood.
3. It flows throughout the blood vessel and helps in the transport of various substances.

Option D

1. Cartilage is solid and pliable.
2. It resists compression.
3. It provides support in bony areas where there is a need for flexibility.

Final answer: Contractile proteins are found in muscles.