Top 30 mcq from animal physiology

Here are **30 MCQs** from the topics of **Animal Physiology**, including **Breathing and Exchange of Gases, Body Fluids and Circulation, Excretory Products and Their Elimination, Locomotion and Movement, Neural Control and Coordination, and Chemical Coordination**. The answers are provided at the end.

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### **Breathing and Exchange of Gases**

1. **Which of the following is the primary site of gas exchange in the lungs?**  

   a) Trachea  

   b) Bronchi  

   c) Alveoli  

   d) Bronchioles  

2. **The volume of air inspired or expired during normal breathing is called:**  

   a) Tidal volume  

   b) Inspiratory reserve volume  

   c) Expiratory reserve volume  

   d) Residual volume  

3. **The oxygen-binding protein in red blood cells is:**  

   a) Hemoglobin  

   b) Myoglobin  

   c) Cytochrome  

   d) Albumin  

4. **The majority of CO₂ is transported in the blood as:**  

   a) Dissolved CO₂  

   b) Carbaminohemoglobin  

   c) Bicarbonate ions  

   d) Carbon monoxide  

5. **The respiratory center in the brain is located in the:**  

   a) Cerebrum  

   b) Medulla oblongata  

   c) Cerebellum  

   d) Hypothalamus  

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### **Body Fluids and Circulation**

6. **The normal pH of human blood is approximately:**  

   a) 6.4  

   b) 7.4  

   c) 8.4  

   d) 9.4  

7. **Which blood cells are responsible for immune responses?**  

   a) Erythrocytes  

   b) Platelets  

   c) Leukocytes  

   d) Thrombocytes  

8. **The pacemaker of the heart is the:**  

   a) AV node  

   b) SA node  

   c) Bundle of His  

   d) Purkinje fibers  

9. **The blood vessel that carries oxygenated blood from the lungs to the heart is the:**  

   a) Pulmonary artery  

   b) Pulmonary vein  

   c) Aorta  

   d) Vena cava  

10. **The liquid part of blood is called:**  

    a) Plasma  

    b) Serum  

    c) Lymph  

    d) Interstitial fluid  

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### **Excretory Products and Their Elimination**

11. **The functional unit of the kidney is the:**  

    a) Nephron  

    b) Glomerulus  

    c) Bowman's capsule  

    d) Loop of Henle  

12. **The process of filtration of blood in the kidney occurs in the:**  

    a) Glomerulus  

    b) Proximal convoluted tubule  

    c) Distal convoluted tubule  

    d) Collecting duct  

13. **The hormone that regulates water reabsorption in the kidney is:**  

    a) Aldosterone  

    b) ADH (Antidiuretic hormone)  

    c) Renin  

    d) Erythropoietin  

14. **The main nitrogenous waste product in humans is:**  

    a) Ammonia  

    b) Urea  

    c) Uric acid  

    d) Creatinine  

15. **The part of the nephron responsible for reabsorption of glucose and amino acids is the:**  

    a) Proximal convoluted tubule  

    b) Distal convoluted tubule  

    c) Loop of Henle  

    d) Collecting duct  

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### **Locomotion and Movement**

16. **The contractile unit of a muscle fiber is the:**  

    a) Sarcomere  

    b) Myofibril  

    c) Actin  

    d) Myosin  

17. **The neurotransmitter released at the neuromuscular junction is:**  

    a) Acetylcholine  

    b) Dopamine  

    c) Serotonin  

    d) GABA  

18. **The bone of the upper arm is called the:**  

    a) Femur  

    b) Humerus  

    c) Tibia  

    d) Radius  

19. **The joint between the skull and the vertebral column is an example of a:**  

    a) Pivot joint  

    b) Hinge joint  

    c) Ball-and-socket joint  

    d) Gliding joint  

20. **The protein present in thin filaments of muscle fibers is:**  

    a) Myosin  

    b) Actin  

    c) Troponin  

    d) Tropomyosin  

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### **Neural Control and Coordination**

21. **The part of the brain responsible for coordination and balance is the:**  

    a) Cerebrum  

    b) Cerebellum  

    c) Medulla oblongata  

    d) Hypothalamus  

22. **The resting membrane potential of a neuron is approximately:**  

    a) -70 mV  

    b) +70 mV  

    c) -90 mV  

    d) +90 mV  

23. **The gap between two neurons is called the:**  

    a) Synapse  

    b) Dendrite  

    c) Axon  

    d) Myelin sheath  

24. **The reflex action is controlled by the:**  

    a) Brain  

    b) Spinal cord  

    c) Peripheral nerves  

    d) Autonomic nervous system  

25. **The neurotransmitter involved in the reward pathway of the brain is:**  

    a) Dopamine  

    b) Serotonin  

    c) Acetylcholine  

    d) GABA  

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### **Chemical Coordination**

26. **The master gland of the endocrine system is the:**  

    a) Thyroid gland  

    b) Pituitary gland  

    c) Adrenal gland  

    d) Pancreas  

27. **The hormone responsible for regulating blood sugar levels is:**  

    a) Insulin  

    b) Glucagon  

    c) Thyroxine  

    d) Cortisol  

28. **The hormone secreted by the adrenal medulla is:**  

    a) Adrenaline  

    b) Cortisol  

    c) Aldosterone  

    d) Testosterone  

29. **The hormone responsible for the development of secondary sexual characteristics in males is:**  

    a) Estrogen  

    b) Progesterone  

    c) Testosterone  

    d) Prolactin  

30. **The hormone that regulates calcium metabolism is:**  

    a) Parathyroid hormone  

    b) Thyroxine  

    c) Calcitonin  

    d) Both a and c  

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### **Answers**

1. c) Alveoli  

2. a) Tidal volume  

3. a) Hemoglobin  

4. c) Bicarbonate ions  

5. b) Medulla oblongata  

6. b) 7.4  

7. c) Leukocytes  

8. b) SA node  

9. b) Pulmonary vein  

10. a) Plasma  

11. a) Nephron  

12. a) Glomerulus  

13. b) ADH  

14. b) Urea  

15. a) Proximal convoluted tubule  

16. a) Sarcomere  

17. a) Acetylcholine  

18. b) Humerus  

19. a) Pivot joint  

20. b) Actin  

21. b) Cerebellum  

22. a) -70 mV  

23. a) Synapse  

24. b) Spinal cord  

25. a) Dopamine  

26. b) Pituitary gland  

27. a) Insulin  

28. a) Adrenaline  

29. c) Testosterone  

30. d) Both a and c