Sindh Mdcat Exclusive Course Biology Support And Movement — Solved MCQs

Question 1

Unpaired facial bones are:

Accepted Answer

D. Mandible, Vomer — Option A: The maxillae are the largest bones in the face and form the upper jaw. The zygomatic bones are the cheekbones. Option B: The palatine bones form the hard palate. The inferior nasal conchae are the small, scroll-shaped bones that project into the nasal cavity. Option C: The nasal bones form the bridge of the nose. The lacrimal bones are small, teardrop-shaped bones that form part of the eye socket. Option D: The facial bones are the bones that form the face of the skull. There are 14 facial bones, of which 6 are paired and 2 are unpaired. The unpaired facial bones are the vomer and the mandible. The vomer is a small, triangular bone that forms the posterior part of the nasal septum. It is the only unpaired bone in the nasal cavity. The mandible is the largest and strongest bone in the face. It forms the lower jaw and is the only movable bone in the skull.

Question 2

Which vertebrae together are called pelvic vertebrae?

Accepted Answer

C. Sacral and coccygeal — The single sacrum is formed by the fusion of five sacral vertebrae. Similarly, the coccyx or tailbone, results from the fusion of four small coccygeal vertebrae. The pelvic skeleton is formed in the area of the back, by the sacrum and the coccyx, and anteriorly and to the left and right sides, by a pair of hip bones. The two hip bones connect the spine with the lower limbs.

Question 3

Which of the following bones are present in the palm of the hand:

Accepted Answer

B. Metacarpals — In the palm of the hand, there are metacarpal bones, as shown below:

Question 4

Bones of the skull are joined by:

Accepted Answer

A. Fibrous joints — Bones of the skull are joined by fibrous joints, which are immovable and fixed types of joints.

Question 5

What do we call the cell surface membrane of a muscle fibre?

Accepted Answer

A. Sarcolemma — 'Sarco-' literally means “muscle”. This prefix is used in terms of normal cell biology to indicate that the term is related to the muscles. On the other hand, '-lemma' means a “confining membrane”; for example, a normal cell’s membrane is simply referred to as the plasma membrane however, a muscle cell’s membrane is referred to as sarcolemma hence we reject option B. The cytoplasm of a striated muscle cell is referred to as 'Sarcoplasm' hence we reject option C as well. Myofibrils are made up of sarcomeres, the functional units of a muscle. The function of the myofibril is to perform muscle contraction via the sliding filament model.

Question 6

Pathway of energy used by muscles converted from food is:

Accepted Answer

C. Food-glycogen-creatine phosphate- ATP — Muscles convert food to energy by first breaking down glycogen to glucose. Glucose is then used to form creatine phosphate which is then metabolized to form ATP.

Question 7

The thick filaments, in a myofibril of muscles, are made of _.

Accepted Answer

B. Myosin — Option A, myoglobin, is a heme-containing protein found in muscles, that binds to oxygen, which it supplies to muscle tissue. Option B, myosin, is the correct answer as it forms thick filaments in a myofibril. Option C, actin, forms thin filaments in a myofibril. Option D, haemoglobin, is the heme-containing protein found in red blood cells and serves to carry oxygen within the blood.

Question 8

Number of bones in the skull:

Accepted Answer

A. 22 — The human skull is composed of 22 bones. These bones include 14 facial bones (a pair of maxilla, mandible, vomer, nasal, a pair of zygomatic, a pair of conchae, a pair of lacrimal and a pair of palatine) and 8 cranial bones (frontal, a pair of parietal, a pair of temporal, occipital, sphenoid and ethmoid.) As per the NUMS answer key 22 is the correct answer. The skull has 22 bones the 6 earbones are not included in the skull bones.

Question 9

The number of muscles in a human body is about:

Accepted Answer

E. 600 — Most sources state that there are over 600 named skeletal muscles in the human body.

Question 10

The diagram shows some of the muscles and bones of the human arm.

Accepted Answer

C. Option C — When the tricep contracts, it causes the arm to straighten and the bicep to relax. The tricep is the primary muscle responsible for extending (straightening) the arm at the elbow joint. The bicep and tricep muscles are located on opposite sides of the upper arm and work in a coordinated manner to move the arm. When the tricep contracts, it generates the force necessary to extend the arm, while the bicep relaxes to allow for this movement. This is because the bicep and tricep muscles act as opposing pairs or antagonistic muscles. When one muscle contracts, the other muscle relaxes to allow for smooth and coordinated movement.

Question 11

Tendon is made up of:

Accepted Answer

B. Modified white fibrous tissue — While fibrous tissue has two forms: cords and sheets. The white fibers run parallel to form cords, called tendons. Tendons attach a muscle to a bone. It consists of collagen fibers and is therefore inelastic. They ensure that the force exerted by muscular contraction is transmitted to the relevant part of the body to be moved. Yellow elastic tissue also has two forms: cords and sheets. Here, cords are called ligaments. Adipose tissue is a fat-storing loose connective tissue. Areolar tissue is the most widely distributed connective tissue in the body.

Question 12

Scapula is the bone of the:

Accepted Answer

C. Pectoral girdle — The shoulder girdle or pectoral girdle is the set of bones in the appendicular skeleton which connects to the arm on each side. In humans it consists of the clavicle and scapula. Refer to the image below:

Question 13

The process of cartilage formation is known as:

Accepted Answer

C. Chondrogenesis — Chondrification (also known as chondrogenesis) is the process by which cartilage is formed from condensed mesenchyme tissue. Chondroblasts are an immature type of cells, which secrete the extracellular matrix of the cartilage. Chondromatosis is a rare, benign (noncancerous) condition that involves the synovium.

Question 14

The significant flight muscle in birds is the:

Accepted Answer

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

Question 15

Pivot joint exists between:

Accepted Answer

D. Ulna and radius — Humerus and ulna - hinge jointHumerus and scapula - ball and socket jointUlna and radius - pivot jointTibia and fibula - synovial joint

Question 16

The multinucleated mass of the bone-breaking cells is called:

Accepted Answer

A. Osteoclasts — 'Osteoclasts' are multinucleated cells that derive from hematopoietic progenitors in the bone marrow, which also give rise to monocytes in peripheral blood. Osteoclasts break down bone tissue, and along with that, osteoblasts and osteocytes form the structural components of bone.

Question 17

Myofibrils, within the muscle fibers, contain thick and thin filaments made up of _ and _ respectively:

Accepted Answer

A. Myosin and Actin — The myofibrils are made up of thick and thin myofilaments, which help give the muscle its striated appearance. The thick filaments are composed of 'myosin', and the thin filaments are predominantly 'actin'.

Question 18

Muscle fiber has many _ and in turns these have many _.

Accepted Answer

A. Myofibrils; Sarcomeres — Each skeletal muscle fibre is a single cylindrical muscle cell. An individual skeletal muscle may be made up of hundreds, or even thousands, of muscle fibres bundled together and wrapped in a connective tissue covering

Question 19

Which of the following sets of bones does not included in the axial skeleton?

Accepted Answer

D. Pectoral girdles, pelvic girdle, and appendages — The axial skeleton includes the bones along the central axis of the body, including the cranium and facial bones, the sternum, ribs, and vertebrae. While, Pectoral girdles, pelvic girdles, and appendages are part of the appendicular skeleton, which attaches to the axial skeleton. They are not part of the axial skeleton. Therefore, option D is correct.

Question 20

Pelvic girdle connects hind limb with:

Accepted Answer

B. Hip bone — Option A: The scapula is the shoulder blade, which is part of the pectoral girdle. The pectoral girdle connects the upper limb with the axial skeleton. The pelvic girdle does not connect to the scapula. Option B: The hip bone is the part of the pelvic girdle that articulates with the femur, the thighbone. The hip bone is the only bone that connects the pelvic girdle to the hind limb. Option C: The sacrum is a triangular bone that is located at the base of the spine. It is made up of five fused vertebrae. The sacrum articulates with the hip bones at the sacroiliac joints. However, the sacrum is not part of the hind limb. Option D: The coccyx is a small, triangular bone that is located at the end of the spine. It is made up of four fused vertebrae. The coccyx articulates with the sacrum at the sacrococcygeal joint. However, the coccyx is not part of the hind limb.

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