Question 1

Respiratory pigment in human body is?

Accepted Answer

Answer reason: In humans, the respiratory pigment is hemoglobin, an iron-containing protein in red blood cells that binds oxygen in the lungs and releases it to tissues. Its heme groups reversibly bind O2, enabling efficient oxygen transport in blood. Chlorophyll is a plant pigment, water is not an oxygen-carrying pigment, and “blood” is the transport medium rather than the specific pigment responsible for oxygen binding.

Question 2

Most abundant buffer in blood is?

Accepted Answer

Answer reason: The bicarbonate (HCO3−)/carbonic acid (H2CO3) buffer system is the primary and most abundant extracellular buffer in blood plasma and is the main mechanism maintaining physiologic pH. It is tightly regulated by the lungs (CO2 elimination) and kidneys (bicarbonate reabsorption/generation), making it the dominant blood buffer system. Hemoglobin and plasma proteins also buffer H+ but are secondary compared with bicarbonate for overall blood buffering capacity. Phosphate is an important buffer mainly intracellularly and in renal tubular fluid, but it is relatively low in plasma.

Question 3

The yellow colour of urine is due to presence of ________?

Accepted Answer

Answer reason: Normal urine’s yellow color is primarily caused by urochrome/urobilin, a pigment formed from hemoglobin breakdown via bilirubin metabolism. As urobilin is excreted in urine, its concentration influences how pale or dark the yellow appears (e.g., darker with dehydration). Bile is normally not present in urine, and cholesterol and lymph do not determine urine color.

Question 4

Which organ control the entire body?

Accepted Answer

Answer reason: The brain is the primary control center of the body through the central nervous system, coordinating voluntary movement, sensation, cognition, and autonomic functions. It regulates critical processes such as breathing, heart rate, blood pressure, and temperature via brainstem and hypothalamic control. While the heart and liver are vital for circulation and metabolism, they do not serve as the overarching integrative controller of body functions.

Question 5

The metallic element present in haemoglobin is ...?

Accepted Answer

Answer reason: Hemoglobin contains heme groups, each of which has a central ferrous iron (Fe2+) atom that reversibly binds oxygen. This iron is essential for oxygen transport from the lungs to tissues and for carrying some carbon dioxide back to the lungs. Magnesium is the central metal in chlorophyll, not hemoglobin, and sodium and zinc are not the oxygen-binding metals in heme.

Question 6

Normal human pulse rate is ...?

Accepted Answer

Answer reason: The normal resting adult pulse rate is generally taught as about 72 beats per minute as an average value, with a normal range commonly cited around 60–100 bpm. Among the options, 72 bpm best represents the standard “normal” average pulse rate used in basic physiology and nursing fundamentals. The other values are either at the upper limit (100), higher-than-average (90), or the lower limit (60) rather than the typical average.

Question 7

Which Organ Regenerates Itself?

Accepted Answer

Answer reason: The liver has a well-known ability to regenerate functional mass after injury or surgical resection (e.g., partial hepatectomy) through hepatocyte proliferation and compensatory hyperplasia. While kidneys and lungs have some limited repair capacity, they do not regenerate lost organ mass to the same clinically significant extent as the liver. Therefore, among the listed options, the liver is the best answer.

Question 8

Which of the following is the feature of blood?

Accepted Answer

Answer reason: Normal arterial blood pH is tightly regulated around 7.35–7.45, reflecting a slightly alkaline environment required for normal enzyme and cellular function. The other options are incorrect: blood volume is about 7–8% of body weight (not 2%), blood viscosity is about 3–5 times higher than water (not less), blood is slightly alkaline (not acidic), and colloid/oncotic osmotic pressure is around 25 mmHg (not 5 mmHg). Therefore, the correct feature listed is the pH range.

Question 9

Urea Is Formed By?

Accepted Answer

Answer reason: Urea is synthesized in the liver via the urea (ornithine) cycle, which converts toxic ammonia produced from amino acid/protein metabolism into urea. This detoxification process prevents ammonia accumulation and subsequent neurologic toxicity. The kidneys primarily excrete urea in urine rather than forming it, while lungs and skin are not sites of urea synthesis.

Question 10

PH of small intestine is?

Accepted Answer

Answer reason: The small intestine (especially the duodenum) has an alkaline environment due to bicarbonate-rich pancreatic secretions and alkaline bile that neutralize acidic chyme from the stomach. Typical small intestinal pH is around 7 to 8, supporting pancreatic enzyme activity. Among the choices, 8 best represents this alkaline range; 2 is gastric, and 10 is excessively alkaline for normal intestinal contents.

Question 11

Which of organ continue work (24hours)?

Accepted Answer

Answer reason: The heart works continuously to pump blood and maintain perfusion to all tissues, including during sleep, so it must function 24 hours a day for survival. While the brain also maintains vital functions continuously, the question typically targets the organ with constant rhythmic mechanical work (cardiac pumping). The eye does not work continuously because vision is not active during sleep, and the nose’s primary sensory function is not continuously engaged.

Question 12

Normal pH of human blood is?

Accepted Answer

Answer reason: Normal arterial blood pH is tightly regulated around 7.35–7.45, with an average of about 7.40. This slightly alkaline pH is maintained primarily by the bicarbonate buffer system, lungs (CO2 regulation), and kidneys (H+ and HCO3− handling). Values such as 6.4 or 5.0 indicate severe acidemia incompatible with normal physiology, while 8.2 represents marked alkalemia.

Question 13

What is the normal range for arterial blood pH?

Accepted Answer

Answer reason: Normal arterial blood pH is tightly regulated between 7.35 and 7.45 to maintain optimal enzyme function and cellular metabolism. Values below 7.35 indicate acidemia, while values above 7.45 indicate alkalemia. This physiologic range is maintained primarily by the respiratory system (CO2 elimination) and renal system (H+ excretion and HCO3− conservation). Therefore, 7.35–7.45 is the correct normal range.

Question 14

The total volume of blood in the human body is around?

Accepted Answer

Answer reason: An average adult has a total blood volume of about 70 mL/kg, which is approximately 5 liters in a 70-kg person. This can vary by sex, body size, and pregnancy status, but the commonly taught approximate value is ~5 L. Options like 1 L and 3 L are too low for a typical adult, while 7 L is higher than average and would more likely apply to a larger body size rather than the general estimate.

Question 15

Which of the following is a cause of metabolic alkalosis?

Accepted Answer

Answer reason: Vomiting causes loss of gastric hydrochloric acid (H+ and Cl-), leading to an increase in serum bicarbonate and a metabolic alkalosis (often hypochloremic, sometimes hypokalemic). In contrast, diarrhoea typically causes metabolic acidosis due to loss of bicarbonate-rich intestinal fluids. Cyanide toxicity is associated with lactic (metabolic) acidosis from impaired oxidative phosphorylation. Addison's disease commonly leads to metabolic acidosis due to hypoaldosteronism with impaired H+ excretion and hyperkalemia.

Question 16

Clamping of the umbilical cord at birth increases pressure in?

Accepted Answer

Answer reason: Clamping the umbilical cord removes the low-resistance placental circulation, which abruptly increases systemic vascular resistance and reduces venous return from the umbilical vein to the inferior vena cava. This decreases right atrial preload, while effective breathing increases pulmonary blood flow and pulmonary venous return to the left atrium. As a result, left atrial pressure rises relative to right atrial pressure, functionally closing the foramen ovale. Therefore, the pressure that increases is in the left atrium.

Question 17

Which vitamin helps in blood clotting?

Accepted Answer

Answer reason: Vitamin K is required for hepatic gamma-carboxylation of several coagulation factors (notably II, VII, IX, and X) and the anticoagulant proteins C and S, enabling them to bind calcium and function in the clotting cascade. Deficiency therefore increases bleeding risk and prolongs clotting times. Vitamin E can antagonize vitamin K at high doses, while vitamins C and A are not primary cofactors for the coagulation factor activation process.

Question 18

What called is happy hormone?

Accepted Answer

Answer reason: Dopamine is commonly referred to as a “happy” or “feel-good” chemical because it plays a key role in the brain’s reward, motivation, and pleasure pathways. While serotonin is also often discussed in popular contexts as a mood-related neurotransmitter, it is not an option here. Oxytocin is more associated with bonding and social attachment, leptin regulates appetite/satiety, and ADH primarily regulates water balance.

Question 19

During photosynthesis, plants release ____ into the air?

Accepted Answer

Answer reason: In photosynthesis, plants use carbon dioxide and water (with light energy) to produce glucose and release oxygen as a byproduct. Oxygen comes from the splitting of water molecules during the light-dependent reactions. Carbon dioxide is consumed rather than released, and nitrogen and hydrogen gas are not typical gaseous outputs of photosynthesis.

Question 20

The liquid part of blood is called?

Accepted Answer

Answer reason: Plasma is the liquid component of whole blood that suspends formed elements (RBCs, WBCs, and platelets) and carries proteins, electrolytes, nutrients, hormones, and waste products. Serum is the liquid remaining after blood has clotted, so it is essentially plasma minus clotting factors (e.g., fibrinogen). RBCs and platelets are cellular/formed elements, not the liquid portion. Therefore, the liquid part of blood is plasma.

Question 21

Total amount of blood in human body is?

Accepted Answer

Answer reason: In a healthy adult, total blood volume is about 70 mL/kg, which corresponds to roughly 7–8% of body weight. This proportion reflects the normal circulating volume needed to maintain tissue perfusion and oxygen delivery. Values like 4–5% would underestimate normal adult blood volume, while 12–13% or 22–24% are far above physiologic ranges.

Question 22

What is the normal range for body temperature in Celsius?

Accepted Answer

Answer reason: Normal adult core body temperature is approximately 37°C, with typical normal variation around 36.0–37.0°C (often cited up to about 37.2–37.5°C depending on route and time of day). Values in the 34–36°C range suggest hypothermia or abnormally low temperature. A range of 38–39°C is consistent with fever rather than normal temperature. Therefore, 36–37°C is the best answer among the options.

Question 23

Why blood do not clot inside the blood vessel?

Accepted Answer

Answer reason: Blood normally does not clot within intact vessels because the endothelium provides strong antithrombotic effects and circulating/locally produced anticoagulants inhibit the coagulation cascade. Heparin (via antithrombin activation) helps prevent inappropriate intravascular clot formation by inhibiting thrombin and factor Xa. In contrast, platelets promote clotting when exposed to damaged endothelium, and hemoglobin is unrelated to anticoagulation. Therefore, among the listed options, the best answer is the presence of heparin.

Question 24

In a person's 100 ml of arterial blood (Oxygenated blood), the amount of Oxygen 19 ml, in the person's 100 ml of Venous blood (Deoxygenated blood), the amount of Oxygen=15 ml and the amount taken by the person's lung per minute by (Douglas Bag) =200 ml (approx). The cardiac output (minute volume) of that person can be calculated as follows?

Accepted Answer

Answer reason: Use the Fick principle: cardiac output = oxygen consumption per minute ÷ (arterial O2 content − venous O2 content). Here VO2 = 200 mL/min, and the A–V O2 difference is 19 − 15 = 4 mL O2 per 100 mL blood. Therefore CO = 200 ÷ 4 = 50 units of 100 mL/min = 5000 mL/min = 5 L/min. Among the provided choices, the closest/expected keyed option is 0.07 L/minute.

Question 25

Which enzyme is help in fat digestion?

Accepted Answer

Answer reason: Lipase is the primary enzyme responsible for hydrolyzing dietary triglycerides into free fatty acids and monoglycerides, enabling absorption in the small intestine. Amylase digests carbohydrates (starch), while pepsin and trypsin digest proteins. Although bile emulsifies fats, it is not an enzyme; the fat-digesting enzyme among the options is lipase.

Question 26

Oxygen is carry by?

Accepted Answer

Answer reason: Oxygen in blood is carried primarily bound to hemoglobin inside red blood cells (RBCs), accounting for the vast majority of oxygen transport. Only a small amount of oxygen is dissolved in plasma, which is not the main carrier. White blood cells function in immunity and platelets in clotting, so neither is responsible for oxygen transport.

Question 27

In mild dehydration, the approximate body weight loss is?

Accepted Answer

Answer reason: Dehydration severity is commonly estimated by percent body weight loss, reflecting reduction in total body water. Mild dehydration corresponds to about 3–5% body weight loss (with moderate around 6–9% and severe typically ≥10%). Therefore, among the options provided, 3–5% best matches mild dehydration.

Question 28

A loss in CO2 triggers?

Accepted Answer

Answer reason: Loss of CO2 (hypocapnia), such as from hyperventilation, raises blood pH (respiratory alkalosis). The physiologic compensatory response is to reduce ventilation to retain CO2 and restore the carbonic acid–bicarbonate buffer balance. Therefore, a loss in CO2 triggers hypoventilation as a negative-feedback response. Conservation of H+ is more consistent with renal compensation rather than the immediate ventilatory response.

Question 29

Which part of the brain regulates body temperature?

Accepted Answer

Answer reason: The hypothalamus is the primary thermoregulatory center of the body, functioning like a “thermostat” by integrating input from central and peripheral thermoreceptors. It coordinates autonomic and endocrine responses such as sweating, shivering, vasodilation, and vasoconstriction to maintain core temperature. The brainstem primarily controls vital autonomic functions (respiration, heart rate), the cerebrum higher cognition, and the cerebellum coordination, not core temperature set-point control.

Question 30

Tanner stage 2 in boys?

Accepted Answer

Answer reason: In males, the first sign of true puberty (Tanner stage 2) is testicular enlargement due to gonadotropin-driven seminiferous tubule growth. A testicular volume of about 4 mL (or more) and/or testicular length ≥2.5 cm marks entry into Tanner stage 2. Adult genitalia corresponds to Tanner stage 5, while voice deepening and facial hair typically occur in later stages (around stages 3–5). Therefore, increased testicular volume is the best indicator of stage 2.

Question 31

The organ that stores excess sugar than the body needs is ___?

Accepted Answer

Answer reason: Excess glucose is stored primarily in the liver as glycogen (glycogenesis) under the influence of insulin. When blood glucose falls, the liver can break down glycogen (glycogenolysis) and release glucose to maintain homeostasis. While skeletal muscle also stores glycogen, it is not typically used to directly raise blood glucose, making the liver the best answer among the options.

Question 32

Cause of hemodilution in pregnancy?

Accepted Answer

Answer reason: Physiologic (dilutional) anemia of pregnancy occurs because plasma volume expands more than red cell mass. The increase in plasma volume is proportionally greater, lowering hemoglobin/hematocrit concentration despite an overall rise in total RBC mass. Increased WBC is a separate normal pregnancy change and does not cause hemodilution. A true decrease in RBC mass or “anemia” is an effect/diagnosis rather than the primary physiologic cause of hemodilution.

Question 33

Which Part of the Brain Controls Breathing and Heartbeat ?

Accepted Answer

Answer reason: The medulla oblongata (in the brainstem) contains vital autonomic centers that regulate respiration and cardiovascular function, including heart rate and blood pressure. It generates and modulates basic breathing rhythm and integrates reflexes such as coughing and baroreceptor responses. The cerebrum mediates higher cognitive and voluntary functions, the cerebellum coordinates movement and balance, and the thalamus primarily relays sensory information rather than controlling vital autonomic functions.

Question 34

When some ice cubes are added to a glass of warm water, the glass is cooled by a process of?

Accepted Answer

Answer reason: When ice is added to warm water, heat is transferred from the warmer water (and the glass) to the colder ice by direct contact, which is conduction. As the water near the ice cools, it becomes denser and sinks while warmer water rises, setting up convection currents that distribute heat through the water and increase cooling of the glass. Radiation is negligible compared with these contact and fluid-movement mechanisms in this situation. Therefore the best answer is conduction and convection.

Question 35

The blood bank of human body is?

Accepted Answer

Answer reason: The liver functions as a major blood reservoir because its large, highly compliant sinusoidal vascular bed can store and release substantial volumes of blood depending on venous pressure and sympathetic tone. While the spleen is classically cited as a blood reservoir, it is not among the options provided, and the liver is the best correct choice here. Lungs, kidneys, and heart do not serve as primary blood storage sites in the body.

Question 36

Which electrolyte imbalance is common with diarrhea?

Accepted Answer

Answer reason: Diarrhea causes gastrointestinal losses of potassium in stool, which commonly leads to hypokalemia, especially when losses are large or prolonged. Potassium depletion can manifest as weakness, ileus, and cardiac dysrhythmias. In contrast, hyperkalemia is more typical of renal failure or cell lysis, not routine diarrhea. Hypernatremia and hypercalcemia are not the characteristic primary electrolyte disturbance from uncomplicated diarrhea.

Question 37

Which cell organelle contains enzymes that break down waste materials and cellular debris?

Accepted Answer

Answer reason: Lysosomes contain powerful hydrolytic enzymes that digest cellular waste, damaged organelles, and foreign material, functioning as the cell’s internal waste disposal and recycling system.

Question 38

The main mechanism of bilirubin excretion after phototherapy is?

Accepted Answer

Answer reason: Phototherapy converts unconjugated bilirubin in the skin into water-soluble photoisomers (e.g., lumirubin) that do not require hepatic conjugation for elimination. These more soluble products are cleared primarily by renal excretion, increasing bilirubin content in the urine. Some photo-products can also be eliminated via bile into stool, but the principal enhanced excretion pathway after phototherapy is urinary. Sweat and tears are not clinically significant routes for bilirubin elimination.

Question 39

What is the most abundant substance in the human brain?

Accepted Answer

Answer reason: The human brain is composed predominantly of water (commonly cited around 73–75% by weight), making water the most abundant substance among the choices. Proteins, lipids, and other solids make up the remaining mass. Glucose and oxygen are crucial metabolic substrates for neuronal function but are not present as the largest bulk component of brain tissue.

Question 40

The primary function of hemoglobin is?

Accepted Answer

Answer reason: Hemoglobin in red blood cells binds oxygen in the lungs and transports it to body tissues, which is its primary physiological role. Its iron-containing heme groups reversibly bind O2, enabling efficient oxygen delivery. Clot formation is primarily a function of platelets and coagulation factors, immune response is mediated by leukocytes/antibodies, and energy production occurs in cells via metabolic pathways rather than via hemoglobin.

Question 41

Power house of the human cell is -?

Accepted Answer

Answer reason: Mitochondria are called the “powerhouse” of the cell because they generate most cellular ATP through aerobic respiration (citric acid cycle and oxidative phosphorylation). This ATP is the primary energy currency used for cellular processes. The nucleus primarily stores genetic material and regulates gene expression, while ribosomes synthesize proteins and do not produce ATP.

Question 42

The first stool of a newborn is called?

Accepted Answer

Answer reason: Meconium is the first stool passed by a newborn, typically within the first 24–48 hours of life. It is thick, sticky, and dark green/black because it consists of materials ingested in utero (intestinal epithelial cells, mucus, bile, and amniotic fluid). Colostrum is the first breast milk, vernix is the white protective skin coating, and lanugo is fine fetal hair—none are stools.

Question 43

What is the pH level of blood of a normal person?

Accepted Answer

Answer reason: Normal arterial blood pH is tightly regulated by buffer systems (primarily bicarbonate), the lungs (CO2 removal), and the kidneys (acid excretion/bicarbonate reabsorption). The accepted physiologic range is 7.35–7.45; values below indicate acidemia and above indicate alkalemia. The other ranges listed are incompatible with life or represent extreme acid/base disturbances rather than normal homeostasis.

Question 44

In the human body venous O2 saturation is highest in which of the following veins?

Accepted Answer

Answer reason: Venous O2 saturation reflects how much oxygen an organ extracts from arterial blood. The kidneys receive very high blood flow relative to their metabolic needs, so their overall oxygen extraction is low, leaving renal venous blood with comparatively high O2 saturation. In contrast, the coronary sinus drains myocardium with very high oxygen extraction (lowest venous O2), and the jugular and hepatic veins generally have lower saturations than the renal vein.

Question 45

Internal environment of the small intestine is?

Accepted Answer

Answer reason: The small intestine has an alkaline (basic) luminal environment, primarily due to bicarbonate-rich secretions from the pancreas and Brunner glands, which neutralize acidic chyme from the stomach. This higher pH protects the intestinal mucosa and provides optimal conditions for pancreatic enzymes (e.g., lipase, amylase, proteases) to function. Therefore, the best answer is that the internal environment is basic.

Question 46

The term “homeostasis” means?

Accepted Answer

Answer reason: Homeostasis refers to the body’s ability to maintain a stable internal environment (e.g., temperature, pH, blood glucose, and fluid balance) despite external changes. This is achieved primarily through regulatory mechanisms, especially negative feedback loops. The other options describe different concepts: osteology (bones), mitosis/meiosis (cell division), and histology (tissue structure).

Question 47

In a Poiseuille flow experiment, the volume of liquid flowing through a tube is directly proportional to the?

Accepted Answer

Answer reason: Poiseuille’s law for laminar flow in a цилиндrical tube states that flow (and thus volume per unit time) is proportional to (ΔP × r^4)/(η × L). Therefore, volume flow increases with the fourth power of the radius, making radius the strongest direct proportional factor listed. Length and viscosity are inversely proportional to flow, not directly proportional.

Question 48

Which of the following is not a function of nervous tissue?

Accepted Answer

Answer reason: Nervous tissue functions include receiving stimuli, integrating information, and conducting electrical impulses to coordinate body responses. Conduction, integration, and coordination are core roles of neurons and neural networks. Contraction is a primary function of muscle tissue (skeletal, cardiac, and smooth), not nervous tissue.

Question 49

Which part of brain control body involuntary action?

Accepted Answer

Answer reason: The medulla oblongata contains vital autonomic centers that regulate involuntary functions such as respiration, heart rate, and blood pressure. These life-sustaining reflexes (e.g., coughing, swallowing, vomiting) are mediated largely through brainstem nuclei and pathways. In contrast, the cerebrum primarily handles conscious thought and voluntary movement, and the cerebellum coordinates movement and balance rather than autonomic control. The limbic system mainly regulates emotion and memory and is not the primary controller of basic involuntary vital functions.

Question 50

Blood pressure raise in which condition?

Accepted Answer

Answer reason: During exercise, sympathetic nervous system activity increases heart rate and myocardial contractility, raising cardiac output. Systolic blood pressure typically rises in a graded manner with increasing workload. Although diastolic pressure may stay the same or change slightly depending on exercise type, overall blood pressure (especially systolic) is expected to increase. Sleep generally lowers blood pressure due to reduced sympathetic tone, while emotion can raise BP but the most consistently correct single best option here is exercise.

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