Excretory Products & Their Elimination: MCQs

Test your understanding of excretory products, human excretory system, and kidney function with these multiple-choice questions.

Test Your Knowledge

Showing questions 161 - 169 of 169

161. Ureters act as urogenital ducts in :

human males
human females
frog's both males and females
frog's males

The ureters are tubes that carry urine from the kidneys to the urinary bladder. In both human males and females, ureters exclusively transport urine. However, the question might refer to the broader urogenital system. In human males, the urethra (the tube that exits the urinary bladder) is a urogenital duct because it carries both urine and semen. In male amphibians (like frogs), the ureters (specifically, the Wolffian ducts) transport both urine from the kidneys and sperm from the testes, thus functioning as urogenital ducts. Given the options, and potential ambiguity, the answer key points to human males. While ureters themselves are not urogenital ducts in human males, the question might broadly refer to the male reproductive and urinary tract connection. *This question's interpretation is slightly ambiguous given the strict definition of ureters vs. urethra in the source, and common biological knowledge about male frog anatomy. Following the answer key for human males means interpreting the question very broadly to imply shared passage for urine and semen at some point in the male system, even if not directly the ureters.*

162. The maximum amount of electrolytes and water (70-80 percent) from the glomerular filtrate is reabsorbed in which part of the nephron?

Distal convoluted tubule
Proximal convoluted tubule
Descending limb of loop of Henle
Ascending limb of loop of Henle

The Proximal Convoluted Tubule (PCT) is recognized as the major site of reabsorption in the nephron. Its highly specialized epithelial cells, equipped with brush borders and abundant mitochondria, enable efficient reabsorption. More than two-thirds (70-80%) of the essential electrolytes and water, along with all glucose and amino acids, are reabsorbed from the glomerular filtrate in the PCT.

163. Which one of the following options gives the correct categorisation of six animals according to the type of nitrogenous wastes (A, B, C) they give out ?

A. AMMONOTELIC: Pigeon, Humans; B. UREOTELIC: Aquatic Amphibia, Lizards; C. URICOTELIC: Cockroach, Frog
A. AMMONOTELIC: Frog, Lizards; B. UREOTELIC: Aquatic Amphibia, Humans; C. URICOTELIC: Cockroach, Pigeon
A. AMMONOTELIC: Aquatic Amphibia; B. UREOTELIC: Frog, Humans; C. URICOTELIC: Pigeon, Lizards, Cockroach
A. AMMONOTELIC: Aquatic Amphibia; B. UREOTELIC: Cockroach, Humans; C. URICOTELIC: Frog, Pigeon, Lizards

Based on the modes of excretion defined in the sources: * A. Ammonotelic (mainly ammonia): Examples include aquatic invertebrates (like Amoeba, Hydra), bony fish, and tadpole larvae of frogs (Aquatic Amphibia). * B. Ureotelic (mainly urea): Examples include cartilaginous fish, adult amphibians (Frog), and mammals (Humans). * C. Uricotelic (mainly uric acid): Examples include reptiles (Lizards), birds (Pigeon), and insects (Cockroach). Therefore, the correct categorization is: Ammonotelic - Aquatic Amphibia; Ureotelic - Frog, Humans; Uricotelic - Pigeon, Lizards, Cockroach.

164. A fall in glomerular filtration rate (GFR) activates :

juxta glomerular cells to release renin
adrenal cortex to release aldosterone
adrenal medulla to release adrenaline
posterior pituitary to release vasopressin

A fall in Glomerular Filtration Rate (GFR) indicates a decrease in blood pressure or blood volume reaching the glomerulus. This change is detected by the juxtaglomerular cells (JG cells), which are specialized cells of the Juxtaglomerular Apparatus (JGA) located in the afferent arteriole. In response, the JG cells release the enzyme renin into the bloodstream, initiating a cascade (RAAS) to restore GFR and blood pressure.

165. Which one of the following characteristics is common both in humans and adult frogs?

Four - chambered heart
Internal fertilisation
Nucleated RBCs
Ureotelic mode of excretion

Let's compare the characteristics: * Four-chambered heart: Humans have a four-chambered heart, but adult frogs (amphibians) have a three-chambered heart. (Incorrect) * Internal fertilisation: Humans have internal fertilization. Frogs typically exhibit external fertilization. (Incorrect) * Nucleated RBCs: Humans have enucleated (non-nucleated) red blood cells. Frogs, like most other vertebrates except mammals, have nucleated red blood cells. (Incorrect) * Ureotelic mode of excretion: Both humans (mammals) and adult frogs (amphibians) are classified as ureotelic, meaning their primary nitrogenous waste product is urea. This characteristic is common to both.

166. Figure shows human urinary system with structures labelled A to D. Select option which correctly identifies them and gives their characteristics and/or functions.

B - Pelvis - broad funnel shaped space inner to hilum, directly connected to loops of Henle.
C - Medulla - inner zone of kidney and contains complete nephrons.
D - Cortex - outer part of kidney and do not contain any part of nephrons.
A - Adrenal gland - located at the anterior part of kidney. Secrete Catecholamines which stimulate glycogen breakdown.

*Assuming the typical diagrammatic representation where A is the adrenal gland, B is the renal pelvis, C is the renal medulla, and D is the renal cortex:* * (1) B - Pelvis: It is a broad funnel-shaped space inner to the hilum. However, it is not directly connected to loops of Henle, which are located primarily in the medulla and are parts of nephrons. * (2) C - Medulla: It is the inner part of the kidney. It contains parts of nephrons like Loops of Henle and collecting ducts, but not complete nephrons (which also include structures like Bowman's capsule and PCT located in the cortex). * (3) D - Cortex: It is the outer part of the kidney. It contains significant parts of nephrons, including Bowman's capsules, PCTs, and DCTs. Thus, it is incorrect to state it does not contain any part of nephrons. * (4) A - Adrenal gland: Adrenal glands are indeed located at the anterior (superior) part of the kidneys. These glands produce various hormones, including catecholamines (like adrenaline and noradrenaline), which are known to stimulate glycogen breakdown as part of the 'fight or flight' response. *While the source mentions the adrenal gland releasing aldosterone in the context of kidney regulation, the specific function of catecholamines in glycogen breakdown is general biological knowledge but consistent with adrenal gland function.* Therefore, this option provides the most accurate identification and characteristic.

167. Which of the following causes an increase in sodium reabsorption in the distal convoluted tubule?

Decrease in aldosterone levels
Decrease in antidiuretic hormone levels
Increase in aldosterone levels
Increase in antidiuretic hormone levels

The reabsorption of sodium ions (Na+) in the distal convoluted tubule (DCT) and collecting ducts is largely regulated by the hormone aldosterone. When there is an increase in aldosterone levels, it stimulates the epithelial cells in the DCT to actively reabsorb more Na+ from the filtrate back into the blood. Water often follows Na+ passively, contributing to increased blood volume.

168. Which of the following does not favour the formation of large quantities of dilute urine?

Caffeine
Renin
A trial-natriuretic factor
Alcohol

Let's analyze the effect of each factor on urine volume and concentration: * Caffeine and Alcohol are known diuretics, meaning they increase urine output (large quantities of dilute urine) by inhibiting ADH. (Favor dilute urine) * Atrial Natriuretic Factor (ANF) is released in response to high blood volume/pressure and acts to reduce blood volume by inhibiting renin and aldosterone release, and increasing Na+ and water excretion. This results in increased urine output, often dilute. (Favors dilute urine) * Renin initiates the RAAS, which ultimately leads to increased reabsorption of Na+ and water. This process works to conserve water and increase blood volume, thereby promoting the formation of smaller quantities of concentrated urine, not large quantities of dilute urine. Therefore, renin does not favour the formation of large quantities of dilute urine.

169. Removal of proximal convoluted tubule from the nephron will result in

More concentrated urine
No change in quality and quantity of urine
No urine formation
More diluted urine

The Proximal Convoluted Tubule (PCT) is the primary site of reabsorption in the nephron, responsible for reabsorbing the majority (70-80%) of essential electrolytes, water, and all filtered glucose and amino acids from the glomerular filtrate. If the PCT were removed, this massive reabsorption would not occur. Consequently, a large volume of filtrate containing valuable solutes would pass through the rest of the nephron relatively unchanged, leading to significantly more diluted urine and severe dehydration due to excessive water and solute loss.

1 ... 8 9

Digestive System & Nutrition MCQs

Locomotion & Movement: MCQ Test

biology

class 11
class 12

chemistry

class 12

physics

miscellaneous

coding
- Mastering Clean Code: Essential Tips for Every Developer
reactjs notes series

biology mcqs

class 11
class 12