Question 1

Which part of the human brain is primarily responsible for maintaining balance and coordination of body movements?

Accepted Answer

The cerebellum, located at the back of the brain, is primarily responsible for coordination, balance, and fine motor control. It integrates sensory information to regulate and coordinate voluntary movements. The cerebrum handles higher functions, the medulla oblongata controls autonomic functions, and the hypothalamus regulates homeostasis.

Question 2

The filtration of blood in the kidneys occurs in which of the following structures?

Accepted Answer

Ultrafiltration of blood occurs in the Bowman's capsule (also called glomerular capsule), which surrounds the glomerulus. The high hydrostatic pressure in the glomerular capillaries forces small molecules like glucose, urea, and water through the capillary wall into the Bowman's capsule, while large molecules like proteins and blood cells remain in the blood. Therefore, answer is A.

Question 3

Which of the following blood components is responsible for blood clotting?

Accepted Answer

Platelets (thrombocytes) are the blood components responsible for initiating blood clotting. When blood vessels are damaged, platelets adhere to the exposed collagen, aggregate, and release chemicals that activate the coagulation cascade, ultimately forming a fibrin clot. Therefore, answer is D.

Question 4

The enzyme that breaks down starch into maltose in the mouth is called:

Accepted Answer

Salivary amylase (also called ptyalin) is the enzyme secreted by salivary glands in the mouth that catalyzes the breakdown of starch into maltose and other smaller sugars. This is the first step of carbohydrate digestion. Therefore, answer is B.

Question 5

Which of the following is the correct sequence of blood flow through the heart chambers?

Accepted Answer

Deoxygenated blood enters the right atrium from the superior and inferior vena cava, flows to the right ventricle, is pumped to the lungs via the pulmonary artery, returns oxygenated to the left atrium via pulmonary veins, flows to the left ventricle, and is pumped to the body via the aorta. Therefore, answer is B.

Question 6

The enzyme that breaks down starch into maltose in the human digestive system is called:

Accepted Answer

Amylase is the enzyme secreted by salivary glands and the pancreas that catalyzes the breakdown of starch into maltose (a disaccharide). Salivary amylase begins this process in the mouth, and pancreatic amylase continues it in the small intestine. Therefore, answer is D.

Question 7

Which of the following hormones is produced by the pancreas and regulates blood glucose levels?

Accepted Answer

Insulin is a hormone secreted by the beta cells of the islets of Langerhans in the pancreas. It lowers blood glucose levels by facilitating glucose uptake into cells and promoting glycogen synthesis. Therefore, answer is B.

Question 8

Vitamin B12 deficiency leads to which of the following conditions?

Accepted Answer

Vitamin B12 (cobalamin) deficiency causes pernicious anaemia, characterized by the production of abnormally large red blood cells (megaloblasts) and reduced red blood cell count. This occurs because B12 is essential for DNA synthesis and red blood cell maturation. Therefore, answer is C.

Question 9

Which of the following vitamins is synthesized by the human body in the skin when exposed to sunlight and is essential for calcium absorption and bone mineralization?

Accepted Answer

Vitamin D is synthesized in the skin when exposed to ultraviolet B (UVB) radiation from sunlight. The precursor 7-dehydrocholesterol is converted to previtamin D3, which is then converted to active vitamin D (calcitriol) in the liver and kidneys. Vitamin D is essential for calcium absorption in the small intestine and bone mineralization. Therefore, answer is D.

Question 10

The human nervous system is divided into the central nervous system (CNS) and peripheral nervous system (PNS). Which of the following correctly describes the structural and functional relationship between these two divisions?

Accepted Answer

The central nervous system (CNS) comprises the brain and spinal cord and serves as the command center for processing information and coordinating responses. The peripheral nervous system (PNS) consists of all neural tissue outside the CNS, including nerves and ganglia, and transmits signals between the CNS and the rest of the body. The PNS is structurally separate from but functionally integrated with the CNS. Therefore, answer is B.

Question 11

The human immune system has two main branches: innate immunity and adaptive immunity. Which of the following statements correctly distinguishes between these two branches in terms of their response characteristics and cellular components?

Accepted Answer

Innate immunity provides immediate, non-specific defense through physical barriers (skin), chemical barriers (lysozyme, stomach acid), and cellular components (neutrophils, macrophages, natural killer cells) that respond within minutes to hours. Adaptive immunity develops over days to weeks and is specific to particular pathogens, involving B lymphocytes (antibody production) and T lymphocytes (cell-mediated immunity). Adaptive immunity also provides immunological memory through memory cells. Therefore, answer is C.

Question 12

Which of the following hormones is produced by the islets of Langerhans in the pancreas and regulates blood glucose levels by promoting glucose uptake into cells?

Accepted Answer

Insulin is the hormone secreted by beta cells of the islets of Langerhans in the pancreas. It lowers blood glucose by facilitating glucose uptake into muscle and adipose tissue cells and promoting glycogen synthesis in the liver. Therefore, answer is B.

Question 13

The human kidney filters blood to form urine through three main processes. Which of the following is NOT one of these processes?

Accepted Answer

The three main processes of urine formation are ultrafiltration (in Bowman's capsule), selective reabsorption (in proximal convoluted tubule and loop of Henle), and tubular secretion (in distal convoluted tubule and collecting duct). Osmosis is a physical process that occurs during reabsorption but is not classified as one of the three main named processes of urine formation. Therefore, answer is D.

Question 14

Which of the following vitamins is fat-soluble and plays a crucial role in blood clotting by acting as a cofactor for the synthesis of prothrombin and other clotting factors?

Accepted Answer

Vitamin K is a fat-soluble vitamin essential for the synthesis of prothrombin (Factor II) and other vitamin K-dependent clotting factors (VII, IX, X) in the liver. It acts as a cofactor for the carboxylation of glutamic acid residues on these proteins, enabling them to bind calcium and phospholipids necessary for the coagulation cascade. Therefore, answer is C.

Question 15

The human nervous system is divided into the central nervous system and peripheral nervous system. The peripheral nervous system is further subdivided into the somatic nervous system and the autonomic nervous system. Which of the following is a function of the somatic nervous system?

Accepted Answer

The somatic nervous system controls voluntary skeletal muscle contractions and transmits sensory information from the skin, muscles, and joints to the central nervous system. It is responsible for conscious, voluntary movements and sensory perception. Therefore, answer is A.

Question 16

The human immune system includes both innate and adaptive immunity. Which of the following cells is part of the innate immune response and acts as a phagocyte to engulf and destroy pathogens without prior sensitization?

Accepted Answer

Macrophages are professional phagocytes derived from monocytes and are key components of the innate immune system. They engulf and destroy pathogens, dead cells, and debris through phagocytosis without requiring prior exposure or sensitization. They also present antigens to T cells, bridging innate and adaptive immunity. Therefore, answer is B.

Question 17

Which of the following hormones is produced by the islets of Langerhans in the pancreas and regulates blood glucose levels by promoting cellular uptake of glucose?

Accepted Answer

Insulin is the hormone secreted by beta cells of the islets of Langerhans in the pancreas. It lowers blood glucose by facilitating glucose uptake into muscle and adipose tissue cells, and promoting glycogen synthesis in the liver. Therefore, answer is B.

Question 18

The human kidney filters waste products from blood to form urine. Which of the following structures is the functional filtration unit of the kidney responsible for ultrafiltration?

Accepted Answer

The nephron is the functional and structural unit of the kidney. Specifically, ultrafiltration occurs in the renal corpuscle, which consists of the glomerulus (capillary network) and Bowman's capsule. The glomerulus filters small molecules like glucose, urea, and water from blood into Bowman's capsule. Therefore, answer is C.

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