All Free Biology MCQs with Answers

• A. 5
• B. 6
• C. 7
• D. 10

Explanation: The horse has 7 cervical vertebra, with the 1st (C1) and 2nd (C2) cervical vertebrae being morphologically extremely modified for their…

• A. Chondrioblasts
• B. Chondriocutosis
• C. Chondrogenesis
• D. None of these

Explanation: Chondrification (also known as chondrogenesis) is the process by which cartilage is formed from condensed mesenchyme tissue.

• A. Pectoral
• B. Tensor
• C. Appendicular
• D. All of these

Explanation: Birds power flight primarily by large pectoralis muscles that depress the wings at the shoulder. Refer to the image below:

• A. Tibia and fibula
• B. Humerus and ulna
• C. Humerus and scapula
• D. Ulna and radius

Explanation: Humerus and ulna - hinge jointHumerus and scapula - ball and socket jointUlna and radius - pivot jointTibia and fibula - synovial joint

• A. 4
• B. 6
• C. 7
• D. 8

Explanation: There are eight carpal bones in hand arranged in two rows of four and four.

• A. Air spaces - Lighter body
• B. Pectoral muscles - Strong pull of wings
• C. Urinary bladder - Producing semisolid urine
• D. Keel - Attachment of muscles

Explanation: The urinary bladder, in most vertebrates, except birds, is the organ for the temporary storage of urine from the kidneys, connected to the…

• A. Osteoclasts
• B. Osteoblasts
• C. Osteogenesis
• D. Osteocytes

Explanation: 'Osteoclasts' are multinucleated cells that derive from hematopoietic progenitors in the bone marrow, which also give rise to monocytes in…

• A. Myosin and Actin
• B. Globulin and Albumin
• C. Troponin and Tropomyosin
• D. Fibrin and Fibrinogen

Explanation: The myofibrils are made up of thick and thin myofilaments, which help give the muscle its striated appearance.

• A. Coccygeal vertebrae
• B. Cervical vertebrae
• C. Sacral vertebrae
• D. Lumbar vertebrae

Explanation: In tetrapods, 'cervical vertebrae' (singular: vertebra) are the vertebrae of the neck, immediately below the skull.

• A. Cardiac
• B. Smooth
• C. Skeletal
• D. Hard

Explanation: It is characteristic for the skeletal muscles to be linked to the bones and be neurogenic (controlled consciously).

• A. Myofibrils; Sarcomeres
• B. Myofibrils; Thin filaments
• C. Myosin; Thin filaments
• D. Myosin; Sarcomeres

Explanation: Each skeletal muscle fibre is a single cylindrical muscle cell. An individual skeletal muscle may be made up of hundreds, or even…

• A. Z-line, H-zone, I-band
• B. I-band, Z-line, H-zone
• C. Z-line, I-band, H-zone
• D. H-zone, I-band, Z-line

Explanation: The mechanism of contraction is the binding of myosin to actin, forming cross-bridges that generate filament movement.

• A. Option A
• B. Option B
• C. Option C
• D. Both A and B
• E. Both A and C

Explanation: Smooth muscles are present in the walls of internal organs such as the stomach, intestine, bladder, etc.

• A. Cranium and facial bones
• B. Sternum, ribs, vertebrae
• C. Lumbar, Thoracic and pelvic bones
• D. Pectoral girdles, pelvic girdle, and appendages

Explanation: The axial skeleton includes the bones along the central axis of the body, including the cranium and facial bones, the sternum, ribs, and…

• A. Exoskeleton
• B. Endoskeleton
• C. Axial skeleton
• D. Appendicular skeleton

Explanation: Option A: An exoskeleton is a hard, external skeleton that protects the body of some animals, such as insects and crabs.

• A. Scapula
• B. Hip bone
• C. Sacrum
• D. Coccyx

Explanation: Option A: The scapula is the shoulder blade, which is part of the pectoral girdle.

• A. Striated
• B. Are multinucleated
• C. Are involuntary
• D. Help in movement

Explanation: Skeletal muscles are striated, multinucleated, and voluntary. They help in movement by contracting and relaxing.

• A. The skull, pectoral girdle, and ribs
• B. The skull, ribs, and bones of arms and legs
• C. The pectoral and pelvic girdles
• D. The ribs, the skull, the sternum, and the vertebrate

Explanation: The axial skeleton involves the ribs, skull, the sternum and the vertebrate.

• A. Breathing
• B. Pumping of blood
• C. Skeletal muscle movement
• D. Blinking of eyes

Explanation: Involuntary functions are those that occur without our conscious control.

• A. 15
• B. 25
• C. 35
• D. 45

Explanation: Sarcomere length is reduced by only about 35% (to a little under 2 mm) by a maximal shortening of the muscle.