All Free Physiology MCQs with Answers

• A. H band
• B. Sarcomere
• C. Sarcoplasm
• D. A line

Explanation: The sarcomere is the basic contractile unit of a myofibril, extending from one Z line to the next.

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

Explanation: Calcium binds to troponin C, causing the troponin-tropomyosin complex to move away from actin’s myosin-binding sites.

• A. Alkaline phosphatase
• B. Osteocalcin
• C. Procollagen marker
• D. Hydroxy proline

Explanation: Alkaline phosphatase, osteocalcin, and procollagen peptides are used as markers of bone formation.

• A. Obesity
• B. Hyperthyroidism
• C. Feeding
• D. Exercise

Explanation: Obesity is associated with a lower basal metabolic rate when expressed per kilogram of body weight, although the total metabolic rate may…

• A. Stensons duct
• B. Naso lacrimal duct
• C. common bile duct
• D. maxillary Sinus

Explanation: The valve of Hasner is the distal mucosal fold at the opening of the nasolacrimal duct into the inferior meatus of the nose.

• A. That the cell is resting
• B. nothing
• C. that the cell is active
• D. that the cell is in transition phase

Explanation: An open-faced or euchromatic nucleus contains relatively dispersed chromatin, allowing active transcription.

• A. Thymine
• B. Cytosine
• C. Guanine
• D. Uracil

Explanation: In DNA, adenine pairs specifically with thymine through two hydrogen bonds, while guanine pairs with cytosine.

• A. RNA contains ribose
• B. DNA carries the information in all organizations
• C. DNA is localized in nucleus
• D. RNA does not contain thymine

Explanation: DNA is the stable repository of hereditary information in cellular organisms, whereas RNA mainly helps express that information through…

• A. Extracellular fluid
• B. Plasma
• C. Intracellular fluid
• D. Whole blood

Explanation: Intracellular fluid forms about two-thirds of total body water, whereas extracellular fluid forms about one-third.

• A. Nucleo protein
• B. Chromo protein
• C. Phospho protein
• D. Simple protein

Explanation: Albumin is a simple protein because hydrolysis yields only amino acids, unlike conjugated proteins such as phosphoproteins and…

• A. Colloid osmotic pressure
• B. Total osmotic pressure
• C. Chloride ion concentrations
• D. Potassium ion concentrations

Explanation: Intracellular fluid and interstitial fluid are both electrically neutral and have nearly equal total osmotic pressure, which prevents…

• A. Anchoring junctions
• B. Tight junctions
• C. Gap junctions
• D. Focal junctions

Explanation: Gap junctions form intercellular channels that allow ions and small cytoplasmic molecules to pass directly between adjacent cells.

• A. Postural position
• B. Covering of the body
• C. Peripheral vasoconstriction
• D. all of the above

Explanation: Thermoregulation uses behavioural and autonomic mechanisms: posture and body covering alter heat loss, while peripheral vasoconstriction…

• A. extracellular sodium concentration
• B. Intracellular potassium concentration
• C. Magnitude of the stimulus
• D. resting membrane potential

Explanation: The action-potential overshoot depends mainly on the sodium equilibrium potential, so it varies with the extracellular sodium…

• A. Sweating
• B. Decrease heat production
• C. Vasodilatation
• D. Non- shivering thermogenesis

Explanation: Cutaneous vasodilatation is the earliest response to heat because it increases blood flow to the skin and promotes heat loss; sweating…

• A. Thyroid extract
• B. Thyroglobulin
• C. Triiodothyronine (T3)
• D. Thyroxine (T4)

Explanation: Daily levothyroxine, synthetic T4, is preferred because it has a longer half-life and is converted in tissues to the active hormone T3.

• A. Parathyroid hormone related protein (PTHrP)
• B. Parathyroid hormone ( PTH)
• C. Interleukin - 6 ( IL- 6)
• D. Calcitonin

Explanation: Many cancers, especially squamous-cell carcinomas, secrete PTH-related protein, which mimics PTH by increasing bone resorption and renal…

• A. Skeletal muscle
• B. Red blood cells
• C. Brain
• D. Kidney tubules

Explanation: Insulin promotes GLUT4 insertion into the cell membrane of skeletal muscle, increasing glucose uptake.

• A. FSH
• B. LH
• C. GH
• D. TSH

Explanation: FSH, LH and TSH are glycoprotein hormones composed of alpha and hormone-specific beta subunits.

• A. Tends to lower blood pressure
• B. Favours protein synthesis
• C. Enhances antigen - antibody reactions
• D. Secretion increases following injury

Explanation: Cortisol secretion rises during stress, including injury, helping maintain blood glucose and cardiovascular responses.