NEET Biology Locomotion and Movement MCQs Set 15

Answer: (c) Lumbar

Explanation:
1. The lumbar vertebrae are the heaviest because they carry the weight of the upper body.
2. The atlas and axis are lighter.

Teacher's Note:
1. Lumbar: strongest.
2. They have large centra.

Answer: (a) Thoracic vertebra

Explanation:
1. Demifacets (half facets) for rib heads are found on the thoracic vertebrae.
2. Cervical vertebrae have transverse foramina instead.

Teacher's Note:
1. Thoracic: 12.
2. Each bears a rib pair.

Answer: (c) Both

Explanation:
1. Both humans and rabbits have 7 pairs of true ribs.
2. So option 3 (both) is correct.

Teacher's Note:
1. True ribs reach the sternum directly.
2. Total ribs: 12 pairs.

Answer: (d) Odontoid process

Explanation:
1. The odontoid process (dens) of the axis acts as a pivot for the atlas, allowing rotation of the head.
2. Zygapophyses are articular processes.

Teacher's Note:
1. Pivot joint between atlas and axis.
2. Olecranon is part of the ulna.

Answer: (b) Skull

Explanation:
1. The zygomatic bone (cheek bone) is a facial bone of the skull.
2. It is not part of girdles or the vertebral column.

Teacher's Note:
1. Face: 14 bones.
2. Zygomatic: cheek.

Answer: (d) Parietal bone and the temporal bone of the skull are joined by fibrous joint.

Explanation:
1. The parietal and temporal bones are joined by a suture, a fibrous joint.
2. The first vertebra is atlas, floating ribs are 11th and 12th, and the glenoid cavity receives the humerus, not the thigh bone.

Teacher's Note:
1. Skull sutures are fibrous joints.
2. They are immovable.

Answer: (c) Floating ribs in humans – 4

Explanation:
1. Humans have 2 pairs of floating ribs, which makes 4 ribs.
2. Cervical vertebrae number 7, proteins use 20 amino acids and diabetes has 2 main types.

Teacher's Note:
1. 7 cervical vertebrae.
2. 20 amino acids.

Answer: (c) Hinge joint

Explanation:
1. The elbow is a hinge joint.
2. It moves in one plane.

Teacher's Note:
1. Hinge joint: knee, elbow.
2. Pivot joint: atlas-axis.

Answer: (d) Osteoporosis-decrease in bone mass and higher chances of fractures with advancing age

Explanation:
1. Osteoporosis is a decrease in bone mass that makes fractures more likely with age.
2. Myasthenia gravis affects neuromuscular transmission, gout is due to uric acid and muscular dystrophy is a genetic degeneration.

Teacher's Note:
1. Osteoporosis: low estrogen in women.
2. Gout: uric acid crystals.

Answer: (c) Accumulation of uric acid crystals in joints causes their inflammation

Explanation:
1. Uric acid crystals deposited in joints cause inflammation (gout).
2. Intervertebral joints are cartilaginous, low estrogen causes osteoporosis, and humans have 12 thoracic vertebrae.

Teacher's Note:
1. Gout is a metabolic disorder.
2. Thoracic vertebrae: 12.

Answer: (d) Gliding joint - between carpals

Explanation:
1. The carpals articulate by gliding joints.
2. Frontal-parietal is fibrous, cervical vertebrae are cartilaginous and humerus-pectoral girdle is ball and socket.

Teacher's Note:
1. Gliding joint: carpals, tarsals.
2. Limited sliding movement.

Answer: (d) Production of body heat

Explanation:
1. The skeletal system supports, protects, allows locomotion, stores minerals and makes blood cells.
2. Body heat is produced mainly by muscles and liver, not by the skeleton.

Teacher's Note:
1. Marrow makes erythrocytes.
2. Bones store calcium.

Answer: (b) Fibrous joint

Explanation:
1. Fibrous joints, such as skull sutures, allow no movement.
2. Synovial joints are freely movable and cartilaginous joints allow little movement.

Teacher's Note:
1. Sutures are immovable.
2. Synovial joints are movable.

Answer: (b) Crystals of calcium phosphate

Explanation:
1. The mineral part of bone is mainly calcium phosphate crystals, which makes up most of its mass.
2. Collagen fibres make up the organic part.

Teacher's Note:
1. Bone: 30 percent organic.
2. 70 percent mineral.

Answer: (d) X = 12, Y = 7 True ribs are attached dorsally to vertebral column and ventrally to the sternum.

Explanation:
1. Humans have 12 pairs of ribs; 7 pairs are true ribs attached dorsally to the vertebral column and ventrally to the sternum.
2. Other options give wrong numbers or wrong explanations.

Teacher's Note:
1. X = 12, Y = 7.
2. True ribs reach the sternum.

Answer: (b) Synovial joint

Explanation:
1. The atlas-axis joint is a pivot joint, which is a type of synovial joint.
2. It is freely movable.

Teacher's Note:
1. Synovial pivot joint.
2. Allows head rotation.

Answer: (a) Cartilaginous joint

Explanation:
1. The pubic symphysis between the two pubic bones is a cartilaginous joint.
2. It is made of fibrocartilage.

Teacher's Note:
1. Cartilaginous joint.
2. Allows slight movement.

Answer: (d) floating ribs

Explanation:
1. The 11th and 12th pairs of ribs are not attached ventrally and are called floating ribs.
2. They are free at the ventral end.

Teacher's Note:
1. Floating ribs: 2 pairs.
2. True ribs: 7 pairs.

Answer: (b) 28

Explanation:
1. Each forelimb has 14 phalanges, so both forelimbs have 28.
2. This follows the formula 2, 3, 3, 3, 3.

Teacher's Note:
1. 14 per limb.
2. 28 in total.

Answer: (c) Correct: a, b, e; Wrong: c, d

Explanation:
1. Statements a, b and e are correct: 206 bones, 12 pairs of ribs and ribs are bicephalic (two articulating surfaces).
2. Statement c is wrong because the sternum is ventral, and d is wrong because most mammals have 7 cervical vertebrae.

Teacher's Note:
1. Sternum: ventral.
2. Cervical vertebrae: 7.

Answer: (d) Digits ® 12 in number

Explanation:
1. Wrist bones are 8, palm bones 5 and ankle bones 7 in each limb.
2. The digits have 14 phalanges, not 12, so the last match is wrong.

Teacher's Note:
1. Digits: 14 phalanges per limb.
2. Carpals: 8.