Question 1

What is the primary product of photosynthesis that plants use for energy?

Accepted Answer

Answer reason: The main stable energy-rich molecule produced is glucose, which can be metabolized via cellular respiration or stored as starch for later use. Oxygen is primarily a byproduct released from water splitting rather than the energy source. Carbon dioxide is a reactant that is fixed into sugars, while ATP made in the light reactions is used transiently to build sugars and is not the end product used for longer-term energy needs.

Question 2

Intravenous therapies often consist of electrolyte replacement therapies. Select the electrolyte that is accurately paired with one of its functions?

Accepted Answer

Answer reason: Calcium is an essential cofactor in multiple steps of the coagulation cascade, enabling activation of clotting factors and formation of a stable fibrin clot. This makes its pairing with blood clotting physiologically accurate and clinically relevant when considering electrolyte replacement and bleeding risk. Potassium is primarily an intracellular cation that supports membrane potential and neuromuscular function, not extracellular fluid regulation. Chloride is the major extracellular anion involved in osmotic balance and acid–base regulation, so linking it to ICF is incorrect.

Question 3

All sense organs send information to the brain via?

Accepted Answer

Answer reason: Afferent (sensory) neurons carry these impulses via peripheral and cranial nerves to the spinal cord/brain for processing and perception. Hormones and blood are chemical/transport systems and do not provide fast, point-to-point encoding of sensory modality and intensity. Muscles are effectors that respond to neural output rather than being the primary pathway for sensory input.

Question 4

Which part of the body receives no blood?

Accepted Answer

Answer reason: The tongue is highly vascular, with a rich arterial supply supporting muscular activity and taste. Teeth are supplied via the dental pulp and periodontal tissues through branches of the maxillary artery. The eyes also have substantial blood supply (e.g., retinal and ciliary circulations) to support high metabolic demand, so no listed structure is truly bloodless.

Question 5

Water Percentage in plasma is?

Accepted Answer

Answer reason: Standard physiology describes plasma as about 90–92% water by volume, which supports transport and maintains osmotic balance and viscosity. Values like 70% are closer to total body water in some contexts, not plasma composition. Values of 100% or 120% are physiologically impossible for a percentage composition of a component.

Question 6

Other name of water intoxication or water intoxication is related to ...?

Accepted Answer

Answer reason: The lowered serum osmolality drives water into cells, particularly brain cells, causing cerebral edema with symptoms such as headache, confusion, seizures, and coma. This matches hypotonic overhydration rather than isotonic overhydration, which expands extracellular volume without lowering sodium concentration. Hypertonic overhydration implies excess sodium relative to water and would raise osmolality, producing opposite fluid shifts.

Question 7

Which process describes the movement of molecules from high to low concentration?

Accepted Answer

Answer reason: This describes diffusion, where solute particles spread until equilibrium is approached. Active transport is a key distractor because it moves substances against the gradient and requires ATP. Osmosis is a specific type of diffusion involving water across a semipermeable membrane, and endocytosis is vesicular bulk transport rather than gradient-driven particle movement.

Question 8

What is the primary function of the lymphatic system?

Accepted Answer

Answer reason: This prevents edema and supports effective blood volume and pressure. While lymphatics also transport dietary lipids from the intestine (via lacteals) and support immune surveillance, these are secondary compared with its core drainage/return function. Oxygen transport is a role of red blood cells in the cardiovascular system, and hormone production is an endocrine function.

Question 9

The nurse is caring for a client having respiratory distress related to an anxiety attack. Recent arterial blood gas values are pH = 7.53, PaO2 = 72 mm Hg (72 mm Hg), PaCO2 = 32 mm Hg (32 mmHg), and HCO3- = 28 mEq/L (28 mmol/L). Which conclusion about the client should the nurse make?

Accepted Answer

Answer reason: The core principle is ABG interpretation: elevated pH indicates alkalemia, and a low PaCO2 points to a primary respiratory alkalosis. Hyperventilation from anxiety causes excessive CO2 blow-off, lowering PaCO2 and raising pH, which matches these findings. The PaO2 of 72 mm Hg suggests mild hypoxemia, which can accompany anxiety-related tachypnea and ventilation–perfusion mismatch. “Acidic blood” is inconsistent with the alkalemic pH, and “overreacting” is a non-clinical, inappropriate conclusion.

Question 10

Which cells in our body are popularly called "soldiers of the human body"?

Accepted Answer

Answer reason: These cells migrate to sites of injury or infection, participate in inflammation, and coordinate immune responses through phagocytosis and antibody/cytokine-mediated mechanisms. Because they actively protect the body, they are commonly referred to as the “soldiers” of the body. Red blood cells mainly transport oxygen and carbon dioxide, while basophils and eosinophils are only specific subtypes of leukocytes rather than the broad group implied by the question.

Question 11

What is the process by which water moves across a cell membrane?

Accepted Answer

Answer reason: This passive movement of water is termed osmosis and does not require cellular energy (ATP). Diffusion is a broader term for solute movement down a concentration gradient, but the specific term for water movement is osmosis. Active transport and endocytosis are energy-dependent processes used for moving solutes against gradients or bringing in large particles, not for the typical transmembrane movement of water.

Question 12

Which organelle is responsible for generating energy for the cell?

Accepted Answer

Answer reason: Mitochondria house the Krebs cycle and the electron transport chain, which generate the bulk of ATP used for cellular work. Ribosomes synthesize proteins, lysosomes digest cellular debris, and the Golgi apparatus modifies and packages proteins/lipids rather than producing ATP. Therefore the organelle most directly responsible for energy generation is the one specialized for ATP production.

Question 13

Which part of the ear is responsible for balance?

Accepted Answer

Answer reason: The semicircular canals sense angular (rotational) acceleration via endolymph movement that bends hair cells in the crista ampullaris. This provides key input for the vestibulo-ocular reflex and equilibrium. In contrast, the cochlea is specialized for hearing, while the Eustachian tube equalizes middle-ear pressure and the tympanic membrane transmits sound vibrations.

Question 14

What is the primary function of the red blood cells?

Accepted Answer

Answer reason: This function is the primary role of erythrocytes in supporting cellular aerobic metabolism. Fighting infection is mainly performed by white blood cells, not erythrocytes. While blood flow can influence heat distribution, thermoregulation is not the primary purpose of red blood cells.

Question 15

What is the process by which water moves through a plant?

Accepted Answer

Answer reason: This evaporation generates negative pressure (tension) that pulls a continuous column of water upward through the xylem via the cohesion-tension mechanism. This explains whole-plant, long-distance transport from roots to leaves. Osmosis is important for water entering root cells locally, but it does not account for the bulk upward flow through vascular tissue.

Question 16

What is the term for the movement of molecules from high to low concentration?

Accepted Answer

Answer reason: This process does not require cellular energy (ATP) and occurs in gases and liquids and across permeable membranes. Osmosis is a specific type of diffusion referring only to water moving across a semipermeable membrane. Mitosis and meiosis are cell division processes and are unrelated to concentration-gradient particle movement.

Question 17

The powerhouse of the cell is —?

Accepted Answer

Answer reason: This occurs primarily via the Krebs cycle and electron transport chain located in the mitochondrial matrix and inner membrane. Because most ATP for normal cell function is produced there, this organelle is termed the cell’s “powerhouse.” By contrast, the nucleus regulates genetic information, ribosomes synthesize proteins, and the Golgi apparatus modifies and packages proteins.

Question 18

Which of the following parts of the brain controls body temperature and hunger?

Accepted Answer

Answer reason: The hypothalamus contains temperature-regulating nuclei (including the preoptic area) that coordinate heat production and heat loss responses via autonomic output. It also regulates hunger and satiety through hypothalamic nuclei (e.g., lateral hypothalamus and ventromedial/arcuate pathways) and hormonal signals such as leptin and ghrelin. In contrast, the thalamus mainly relays sensory information, and the cerebellum primarily coordinates movement and balance, making them poor fits for these homeostatic roles.

Question 19

The mother of a newborn child calls the pediatrician’s office with concern that her child is often jolted or startled when waking from sleep. What reflex is the mother likely witnessing?

Accepted Answer

Answer reason: It is commonly noticed when infants are awakened or startled by noise or movement, matching the mother’s description. Rooting is a feeding-related reflex elicited by stroking the cheek, Babinski is an upgoing plantar response to sole stimulation, and tonic neck is a postural “fencing” response to head turning. Persistence of a strong Moro beyond early infancy can be abnormal, but its presence in a newborn is expected.

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Physiology Practice Test 27

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