All Free Biology MCQs with Answers

• A. Growing bone
• B. Mature bones
• C. Lamellar bone
• D. Secondary bone

Explanation: Option A is the correct option because 'Hyaline cartilage' exists on the sternal ends of the ribs, in the larynx, trachea, and bronchi…

• A. Cork cambium
• B. Vascular cambium
• C. Pith
• D. Both Options A and B are correct

Explanation: Option D is correct since both types of cambiums are responsible for secondary growth in the vascular bundle and that in turn causes an…

• A. Myofibril
• B. Cross bridges
• C. Z band
• D. Sarcomere

Explanation: Option D is correct it is also a PTB fact. Sarcomere is a region of myofibril btw two successive Z-line and is the smallest contractile…

• A. Syndesmosis
• B. Sutures
• C. Gomphosis
• D. None of these

Explanation: A gomphosis is the specialised fibrous joint that anchors the root of a tooth into its bony socket within the maxillary bone (upper jaw)…

• A. Endosymbiotic theory
• B. Central Dogma theory
• C. Cross-bridge theory
• D. Sliding filament theory

Explanation: The sliding filament theory is the explanation for how muscles contract to produce force.

• A. Condyloid joint is triaxial
• B. Synovial fluid reduces friction
• C. Coronal suture is for parietal and frontal bone articulation
• D. Synostosis is a bony joint

Explanation: Condyloid joints, also known as ellipsoid joints, are composed of an egg-shaped bone known as a condyle that fits into a similarly shaped…

• A. Tropomyosin
• B. Troponin
• C. Both a and b
• D. None of these

Explanation: Option A is correct because "tropomyosin" constantly covers the myosin binding sites on actin until "troponin" receives Calcium ions for…

• A. There are many blood vessels in the cartilage
• B. It is a form of connective tissue
• C. It covers ends of the bone at the joint
• D. Both A and B

Explanation: Option A is correct as "cartilage" is the main type of connective tissue found throughout the body in bones, joints, spine, lungs and…

• A. Articular capsule
• B. Articular cartilage
• C. Synovial fluid
• D. Fibrocartilage

Explanation: Option D is correct as "fibrocartilage" is found in the intervertebral discs as well as some synovial joints.

• A. 3
• B. 6
• C. 7
• D. 2

Explanation: Myosin forms thick filaments (16 nm in diameter) and actin forms thinner filaments (7-8 nm in diameter).

• A. Motor unit
• B. Neuromuscular junction
• C. Neural unit
• D. Microtubules

Explanation: A motor neuron and all of the skeletal muscle cells it stimulates is called a motor unit.

• A. Radio-ulnar joints
• B. Tibiofibular joints
• C. Gomphosis
• D. Periodontal ligament

Explanation: The periodontal ligament, commonly known as the PDL, is a soft connective tissue between the inner wall of the alveolar socket and the…

• A. Titin
• B. Myosin
• C. Actin
• D. All of these

Explanation: Option D is correct since the force-tension curve/ length-tension curve describes the maximum isometric force, a muscle generates, as…

• A. Actin
• B. Myosin
• C. Troponin
• D. Tropomyosin

Explanation: Option B is correct since the myosin head binds to the ATP and adopts a high energy configuration to bind to the myosin-binding site on…

• A. Fibrous joints
• B. Cartilaginous joints
• C. Sinovial joints
• D. None of these

Explanation: Option A is correct since fibrous joints are connected by dense, tough connective tissue that is rich in collagen fibers.Option B is…

• A. H zone and myosin
• B. H zone and actin
• C. I band and A band
• D. H zone and I band

Explanation: The H zone and I band are two regions of the sarcomere, which is the basic unit of muscle contraction.

• A. Saddle joint.
• B. Condyloid joint.
• C. Ball and socket joint.
• D. None of these.

Explanation: An ellipsoidal joint is also known as a condyloid joint. This type of joint is a synovial joint that allows for movement in two planes…

• A. The fibers that make up skeletal muscles
• B. The smallest unit of a smooth muscle
• C. A myosin fibril
• D. The contractile unit of a muscle cell

Explanation: A sarcomere is the basic contractile unit of muscle fiber. Each sarcomere is composed of two main protein filaments-actin and myosin-which…

• A. Cytoplasm of other cell
• B. Nucleoplasm
• C. Mitochondria
• D. Cell membrane

Explanation: Sarcoplasm is the cytoplasm of a muscle fibre. It is a water solution containing ATP and phosphagens, as well as the enzymes and…

• A. Nerve impulse
• B. Energy
• C. Calcium
• D. All of these

Explanation: Nerve impulse reaches the neuro-muscular junction and calcium is released in the muscle cell, and when contraction occurs and ATP is used…