The list of the entities in the population is referred to as

Correct Answer: A

Rationale: A sample frame is the list of all population entities from which a sample is drawn. 'Sample frame,' is correct, as per statistical methodology (e.g., Cochran), providing the sampling base (e.g., a hospital staff list). 'Sampling unit,' is an individual element. 'Sampling fraction,' is the sample-to-population ratio. 'Sample size,' is the number sampled. The frame's role as the master list ensures representativeness, making A the precise answer.

Correct Answer: B

Rationale: Cardiac output (CO) is the product of heart rate (HR) and stroke volume (SV), and adrenaline (epinephrine) enhances both by increasing HR and contractility. 'Adrenaline,' is correct because it acts via beta-adrenergic receptors to boost sympathetic stimulation, as per physiology texts like Guyton and Hall's Medical Physiology. 'Aldosterone,' regulates blood volume and pressure long-term, not directly affecting rate or force acutely. 'Angiotensin,' primarily causes vasoconstriction and aldosterone release, indirectly influencing CO. 'Thyroxin,' increases metabolism and HR over time but lacks adrenaline's immediate, dual impact on rate and force. Adrenaline's rapid action—seen in fight-or-flight responses—makes it uniquely suited to elevate CO by enhancing both parameters, distinguishing B as the precise answer, supported by its role in cardiovascular regulation during stress.

Correct Answer: C

Rationale: The pancreas functions as both an exocrine gland (digestive enzymes via ducts) and an endocrine gland (insulin, glucagon into blood). 'Pancreas,' is correct, per anatomy texts like Moore, with acini (exocrine) and islets (endocrine). 'Adrenal gland,' and 'Pituitary gland,' are purely endocrine. 'Thyroid gland,' is endocrine only. The pancreas' dual role in digestion and glucose regulation makes C the precise answer, unique among endocrine glands.

Correct Answer: B

Rationale: Polyunsaturated fatty acids (PUFAs) have multiple double bonds. 'Oleic acid,' is correct as the exception, a monounsaturated fatty acid with one double bond, per biochemistry (e.g., Harper's). 'Linoleic acid,' 'Arachidonic acid,' and 'Linolenic acid,' are PUFAs with multiple bonds, essential in diets. Oleic acid's single unsaturation contrasts with PUFAs' plurality, making B the precise answer.

Correct Answer: B

Rationale: The male urethra averages 20 cm, spanning prostatic, membranous, and spongy parts. '20 cm,' is correct, per anatomy texts like Netter, varying slightly (18-22 cm). '15 cm,' is short. '25 cm,' and '30 cm,' exceed typical length. The 20 cm standard reflects its path from bladder to external meatus, making B the accurate answer.