Selina Textbook Solutions: The Excretory System

 Page 1


 
  
A. MULTIPLE CHOICE TYPE: 
(select the most appropriate option in each case) 
 
Question 1:  
Excretion primarily involves 
(a) removal of all byproducts during catabolism 
(b) removal by products during anabolism 
(c) removal of nitrogenous wastes 
(d) throwing out excess water  
Solution 1: 
(c) Removal of nitrogenous wastes. 
 
 
Question 2: 
Maximum amount of water from the glomerular filtrate is reabsorbed in 
(a) proximal convoluted tubule 
(b) descending limbs of loop of Henle 
(c) ascending limb of loop of Henle 
(d) distal convoluted tubule 
Solution 2: 
(a) Proximal convoluted tubule 
 
 
Question 3: 
Which one of the following in real sense is NOT an excretory activity? 
(a) giving out carbon dioxide 
(b) passing out faecal matter 
(c) sweating  
(d) Removal of urea 
Solution 3: 
(c) Sweating 
 
 
Question 4: 
In humans, urea is formed in  
(a) ureter 
(b) liver  
(c) spleen 
Class X Chapter 7 – The Excretory System Biology 
______________________________________________________________________________ 
Page 2


 
  
A. MULTIPLE CHOICE TYPE: 
(select the most appropriate option in each case) 
 
Question 1:  
Excretion primarily involves 
(a) removal of all byproducts during catabolism 
(b) removal by products during anabolism 
(c) removal of nitrogenous wastes 
(d) throwing out excess water  
Solution 1: 
(c) Removal of nitrogenous wastes. 
 
 
Question 2: 
Maximum amount of water from the glomerular filtrate is reabsorbed in 
(a) proximal convoluted tubule 
(b) descending limbs of loop of Henle 
(c) ascending limb of loop of Henle 
(d) distal convoluted tubule 
Solution 2: 
(a) Proximal convoluted tubule 
 
 
Question 3: 
Which one of the following in real sense is NOT an excretory activity? 
(a) giving out carbon dioxide 
(b) passing out faecal matter 
(c) sweating  
(d) Removal of urea 
Solution 3: 
(c) Sweating 
 
 
Question 4: 
In humans, urea is formed in  
(a) ureter 
(b) liver  
(c) spleen 
Class X Chapter 7 – The Excretory System Biology 
______________________________________________________________________________ 
Class X Chapter 8 – The Excretory System Biology 
______________________________________________________________________________ 
(d) Kidney 
Solution 4: 
(b) liver 
 
 
B. VERY SHORT ANSWER TYPE: 
  
Question 1: 
Name the following: 
(a) The organ which produces urea 
(b) The outer region of kidney containing the Bowman’s capsule 
(c) The tuft of capillaries inside the Bowman’s capsule 
(d) The part of kidney tubules where the term urine is first used for the fluid in it 
(e) The vein in which urea concentration is maximum 
Solution 1: 
(a) Liver 
(b) Cortex 
(c) Glomerulus 
(d) Collecting duct 
(e) Renal artery (Renal vein has urea but renal artery has higher concentration of urea as 
compared to renal vein). 
 
 
Question 2: 
Given below are two sets (a and b) of five terms each. Rewrite the terms in their correct order 
so as to be in logical sequence. 
(a) Afferent arteriole, renal vein, capillary network, glomerulus, efferent arteriole. 
(b) Renal artery, urethra, ureter, kidney, urinary bladder. 
Solution 2: 
(a) Afferent arteriole, glomerulus, efferent arteriole, capillary network, renal vein 
(b) Renal artery, kidney, ureter, urinary bladder, urethra 
 
 
Question 3: 
In each one of the following sets of body parts or substances or processed, pick out the one item 
which overall includes the remaining foir. 
(a) Glomerular filtrate, bowman’s capsule, ultrafiltration, glomerulus, blood plasma. 
(b) skin, liver, lungs, kidney, excretion 
(c) ADH, Water, pituitary, osmoregulation, urine 
(d) CO2, bile pigments, water, excretion, urea. 
Solution 3: 
Page 3


 
  
A. MULTIPLE CHOICE TYPE: 
(select the most appropriate option in each case) 
 
Question 1:  
Excretion primarily involves 
(a) removal of all byproducts during catabolism 
(b) removal by products during anabolism 
(c) removal of nitrogenous wastes 
(d) throwing out excess water  
Solution 1: 
(c) Removal of nitrogenous wastes. 
 
 
Question 2: 
Maximum amount of water from the glomerular filtrate is reabsorbed in 
(a) proximal convoluted tubule 
(b) descending limbs of loop of Henle 
(c) ascending limb of loop of Henle 
(d) distal convoluted tubule 
Solution 2: 
(a) Proximal convoluted tubule 
 
 
Question 3: 
Which one of the following in real sense is NOT an excretory activity? 
(a) giving out carbon dioxide 
(b) passing out faecal matter 
(c) sweating  
(d) Removal of urea 
Solution 3: 
(c) Sweating 
 
 
Question 4: 
In humans, urea is formed in  
(a) ureter 
(b) liver  
(c) spleen 
Class X Chapter 7 – The Excretory System Biology 
______________________________________________________________________________ 
Class X Chapter 8 – The Excretory System Biology 
______________________________________________________________________________ 
(d) Kidney 
Solution 4: 
(b) liver 
 
 
B. VERY SHORT ANSWER TYPE: 
  
Question 1: 
Name the following: 
(a) The organ which produces urea 
(b) The outer region of kidney containing the Bowman’s capsule 
(c) The tuft of capillaries inside the Bowman’s capsule 
(d) The part of kidney tubules where the term urine is first used for the fluid in it 
(e) The vein in which urea concentration is maximum 
Solution 1: 
(a) Liver 
(b) Cortex 
(c) Glomerulus 
(d) Collecting duct 
(e) Renal artery (Renal vein has urea but renal artery has higher concentration of urea as 
compared to renal vein). 
 
 
Question 2: 
Given below are two sets (a and b) of five terms each. Rewrite the terms in their correct order 
so as to be in logical sequence. 
(a) Afferent arteriole, renal vein, capillary network, glomerulus, efferent arteriole. 
(b) Renal artery, urethra, ureter, kidney, urinary bladder. 
Solution 2: 
(a) Afferent arteriole, glomerulus, efferent arteriole, capillary network, renal vein 
(b) Renal artery, kidney, ureter, urinary bladder, urethra 
 
 
Question 3: 
In each one of the following sets of body parts or substances or processed, pick out the one item 
which overall includes the remaining foir. 
(a) Glomerular filtrate, bowman’s capsule, ultrafiltration, glomerulus, blood plasma. 
(b) skin, liver, lungs, kidney, excretion 
(c) ADH, Water, pituitary, osmoregulation, urine 
(d) CO2, bile pigments, water, excretion, urea. 
Solution 3: 
Class X Chapter 8 – The Excretory System Biology 
______________________________________________________________________________ 
(a) Ultrafiltration 
(b) Excretion 
(c) Osmoregulation 
(d) Excretion 
 
 
C. SHORT ANSWER TYPE: 
 
Question1: 
Write down the functional activity of the following parts, 
(a) Glomerulus ………………… 
(b)  Henle's loop ……………… 
(c) Ureter ……………………… 
(d) Renal artery ……………… 
(e) Urethra …………………… 
Solution 1: 
(a) Glomerulus is involved in the process of ultrafiltration. The liquid part of the blood which is 
plasma including urea, salts, glucose filters out from the glomerulus into the renal tubule. 
(b) Henle's loop is involved in reabsorption of water and sodium ions. 
(c) Ureter carries urine to the urinary bladder by ureteral peristalsis. 
(d) Renal artery supplied blood to the kidney. 
(e) Urethra is involved in the process of micturition i.e. expelling urine out of the body. 
 
Question 2: 
Why is excretion necessary? Name the common excretory substance in our body. 
Solution 2: 
Excretion helps in removing toxic wastes from our body and it also plays an important role 
osmoregulation i.e. the maintenance of the homeostasis of the body. 
Carbon dioxide, water, nitrogenous compounds such as urea, uric acid and excess salts are some 
common excretory products. 
 
 
Question 3: 
What is a uriniferous tubule? How does it function? 
Solution 3: 
A uriniferous tubule also known as the kidney tubule is the structural and functional unit of the 
kidney. 
It takes in impure blood from the renal artery and removes wastes in the form of urine. It also 
provides a larger surface area for reabsorption of salts and water. 
 
Page 4


 
  
A. MULTIPLE CHOICE TYPE: 
(select the most appropriate option in each case) 
 
Question 1:  
Excretion primarily involves 
(a) removal of all byproducts during catabolism 
(b) removal by products during anabolism 
(c) removal of nitrogenous wastes 
(d) throwing out excess water  
Solution 1: 
(c) Removal of nitrogenous wastes. 
 
 
Question 2: 
Maximum amount of water from the glomerular filtrate is reabsorbed in 
(a) proximal convoluted tubule 
(b) descending limbs of loop of Henle 
(c) ascending limb of loop of Henle 
(d) distal convoluted tubule 
Solution 2: 
(a) Proximal convoluted tubule 
 
 
Question 3: 
Which one of the following in real sense is NOT an excretory activity? 
(a) giving out carbon dioxide 
(b) passing out faecal matter 
(c) sweating  
(d) Removal of urea 
Solution 3: 
(c) Sweating 
 
 
Question 4: 
In humans, urea is formed in  
(a) ureter 
(b) liver  
(c) spleen 
Class X Chapter 7 – The Excretory System Biology 
______________________________________________________________________________ 
Class X Chapter 8 – The Excretory System Biology 
______________________________________________________________________________ 
(d) Kidney 
Solution 4: 
(b) liver 
 
 
B. VERY SHORT ANSWER TYPE: 
  
Question 1: 
Name the following: 
(a) The organ which produces urea 
(b) The outer region of kidney containing the Bowman’s capsule 
(c) The tuft of capillaries inside the Bowman’s capsule 
(d) The part of kidney tubules where the term urine is first used for the fluid in it 
(e) The vein in which urea concentration is maximum 
Solution 1: 
(a) Liver 
(b) Cortex 
(c) Glomerulus 
(d) Collecting duct 
(e) Renal artery (Renal vein has urea but renal artery has higher concentration of urea as 
compared to renal vein). 
 
 
Question 2: 
Given below are two sets (a and b) of five terms each. Rewrite the terms in their correct order 
so as to be in logical sequence. 
(a) Afferent arteriole, renal vein, capillary network, glomerulus, efferent arteriole. 
(b) Renal artery, urethra, ureter, kidney, urinary bladder. 
Solution 2: 
(a) Afferent arteriole, glomerulus, efferent arteriole, capillary network, renal vein 
(b) Renal artery, kidney, ureter, urinary bladder, urethra 
 
 
Question 3: 
In each one of the following sets of body parts or substances or processed, pick out the one item 
which overall includes the remaining foir. 
(a) Glomerular filtrate, bowman’s capsule, ultrafiltration, glomerulus, blood plasma. 
(b) skin, liver, lungs, kidney, excretion 
(c) ADH, Water, pituitary, osmoregulation, urine 
(d) CO2, bile pigments, water, excretion, urea. 
Solution 3: 
Class X Chapter 8 – The Excretory System Biology 
______________________________________________________________________________ 
(a) Ultrafiltration 
(b) Excretion 
(c) Osmoregulation 
(d) Excretion 
 
 
C. SHORT ANSWER TYPE: 
 
Question1: 
Write down the functional activity of the following parts, 
(a) Glomerulus ………………… 
(b)  Henle's loop ……………… 
(c) Ureter ……………………… 
(d) Renal artery ……………… 
(e) Urethra …………………… 
Solution 1: 
(a) Glomerulus is involved in the process of ultrafiltration. The liquid part of the blood which is 
plasma including urea, salts, glucose filters out from the glomerulus into the renal tubule. 
(b) Henle's loop is involved in reabsorption of water and sodium ions. 
(c) Ureter carries urine to the urinary bladder by ureteral peristalsis. 
(d) Renal artery supplied blood to the kidney. 
(e) Urethra is involved in the process of micturition i.e. expelling urine out of the body. 
 
Question 2: 
Why is excretion necessary? Name the common excretory substance in our body. 
Solution 2: 
Excretion helps in removing toxic wastes from our body and it also plays an important role 
osmoregulation i.e. the maintenance of the homeostasis of the body. 
Carbon dioxide, water, nitrogenous compounds such as urea, uric acid and excess salts are some 
common excretory products. 
 
 
Question 3: 
What is a uriniferous tubule? How does it function? 
Solution 3: 
A uriniferous tubule also known as the kidney tubule is the structural and functional unit of the 
kidney. 
It takes in impure blood from the renal artery and removes wastes in the form of urine. It also 
provides a larger surface area for reabsorption of salts and water. 
 
Class X Chapter 8 – The Excretory System Biology 
______________________________________________________________________________ 
Question 4: 
Why is it necessary to maintain a normal osmotic concentration of the blood? 
Solution 4: 
Maintaining a normal osmotic concentration in the body means regulating the percentage of 
water and salts. If this regulation mechanism fails we either end up losing vital salts and water 
or may accumulate unwanted salts and excess water in our body. 
 
 
Question 5:  
If you donate one kidney to a needy patient, would it cause any harm to you? Give reason. 
Solution 5: 
If one kidney is donated to a needy patient, the other kidney alone is sufficient for removing 
wastes or excretion. Thus, the donor can live a normal life. 
 
 
Question 6: 
In summer the urine is slightly thicker than in winter explain the reason. 
Solution 6: 
During summer, a considerable part of water is lost through perspiration so the kidneys have to 
reabsorb more water from the urine. This makes the urine thicker in summer than in winters. 
 
 
Question 7: 
Differentiate between the following pairs of terms: 
(a) Bowman’s capsule and malpighian capsule. 
(b) Renal cortex and renal medulla 
(c) Renal pelvis and renal papilla 
(d) Urea and urine 
(e) Excretion and katabolism 
Solution 7: 
(a) Bowman's capsule is a thin walled cup containing the glomerulus. This Bowman's capsule 
along with the glomerulus is known as malpighian capsule. 
(b) The renal cortex is the outer darker region of the kidney whereas the renal medulla is the 
inner lighter region of the kidney. 
(c) Renal pelvis is the expanded front end of the ureter in the kidney whereas the renal 
papilla is the apex of the renal pyramid which projects into the pelvis. 
(d) Urea is the chief excretory product which is excreted in the form of urine whereas urine is 
the filtrate left after reabsorption and tubular secretion which contains 95% water and 5% 
solid wastes. 
Page 5


 
  
A. MULTIPLE CHOICE TYPE: 
(select the most appropriate option in each case) 
 
Question 1:  
Excretion primarily involves 
(a) removal of all byproducts during catabolism 
(b) removal by products during anabolism 
(c) removal of nitrogenous wastes 
(d) throwing out excess water  
Solution 1: 
(c) Removal of nitrogenous wastes. 
 
 
Question 2: 
Maximum amount of water from the glomerular filtrate is reabsorbed in 
(a) proximal convoluted tubule 
(b) descending limbs of loop of Henle 
(c) ascending limb of loop of Henle 
(d) distal convoluted tubule 
Solution 2: 
(a) Proximal convoluted tubule 
 
 
Question 3: 
Which one of the following in real sense is NOT an excretory activity? 
(a) giving out carbon dioxide 
(b) passing out faecal matter 
(c) sweating  
(d) Removal of urea 
Solution 3: 
(c) Sweating 
 
 
Question 4: 
In humans, urea is formed in  
(a) ureter 
(b) liver  
(c) spleen 
Class X Chapter 7 – The Excretory System Biology 
______________________________________________________________________________ 
Class X Chapter 8 – The Excretory System Biology 
______________________________________________________________________________ 
(d) Kidney 
Solution 4: 
(b) liver 
 
 
B. VERY SHORT ANSWER TYPE: 
  
Question 1: 
Name the following: 
(a) The organ which produces urea 
(b) The outer region of kidney containing the Bowman’s capsule 
(c) The tuft of capillaries inside the Bowman’s capsule 
(d) The part of kidney tubules where the term urine is first used for the fluid in it 
(e) The vein in which urea concentration is maximum 
Solution 1: 
(a) Liver 
(b) Cortex 
(c) Glomerulus 
(d) Collecting duct 
(e) Renal artery (Renal vein has urea but renal artery has higher concentration of urea as 
compared to renal vein). 
 
 
Question 2: 
Given below are two sets (a and b) of five terms each. Rewrite the terms in their correct order 
so as to be in logical sequence. 
(a) Afferent arteriole, renal vein, capillary network, glomerulus, efferent arteriole. 
(b) Renal artery, urethra, ureter, kidney, urinary bladder. 
Solution 2: 
(a) Afferent arteriole, glomerulus, efferent arteriole, capillary network, renal vein 
(b) Renal artery, kidney, ureter, urinary bladder, urethra 
 
 
Question 3: 
In each one of the following sets of body parts or substances or processed, pick out the one item 
which overall includes the remaining foir. 
(a) Glomerular filtrate, bowman’s capsule, ultrafiltration, glomerulus, blood plasma. 
(b) skin, liver, lungs, kidney, excretion 
(c) ADH, Water, pituitary, osmoregulation, urine 
(d) CO2, bile pigments, water, excretion, urea. 
Solution 3: 
Class X Chapter 8 – The Excretory System Biology 
______________________________________________________________________________ 
(a) Ultrafiltration 
(b) Excretion 
(c) Osmoregulation 
(d) Excretion 
 
 
C. SHORT ANSWER TYPE: 
 
Question1: 
Write down the functional activity of the following parts, 
(a) Glomerulus ………………… 
(b)  Henle's loop ……………… 
(c) Ureter ……………………… 
(d) Renal artery ……………… 
(e) Urethra …………………… 
Solution 1: 
(a) Glomerulus is involved in the process of ultrafiltration. The liquid part of the blood which is 
plasma including urea, salts, glucose filters out from the glomerulus into the renal tubule. 
(b) Henle's loop is involved in reabsorption of water and sodium ions. 
(c) Ureter carries urine to the urinary bladder by ureteral peristalsis. 
(d) Renal artery supplied blood to the kidney. 
(e) Urethra is involved in the process of micturition i.e. expelling urine out of the body. 
 
Question 2: 
Why is excretion necessary? Name the common excretory substance in our body. 
Solution 2: 
Excretion helps in removing toxic wastes from our body and it also plays an important role 
osmoregulation i.e. the maintenance of the homeostasis of the body. 
Carbon dioxide, water, nitrogenous compounds such as urea, uric acid and excess salts are some 
common excretory products. 
 
 
Question 3: 
What is a uriniferous tubule? How does it function? 
Solution 3: 
A uriniferous tubule also known as the kidney tubule is the structural and functional unit of the 
kidney. 
It takes in impure blood from the renal artery and removes wastes in the form of urine. It also 
provides a larger surface area for reabsorption of salts and water. 
 
Class X Chapter 8 – The Excretory System Biology 
______________________________________________________________________________ 
Question 4: 
Why is it necessary to maintain a normal osmotic concentration of the blood? 
Solution 4: 
Maintaining a normal osmotic concentration in the body means regulating the percentage of 
water and salts. If this regulation mechanism fails we either end up losing vital salts and water 
or may accumulate unwanted salts and excess water in our body. 
 
 
Question 5:  
If you donate one kidney to a needy patient, would it cause any harm to you? Give reason. 
Solution 5: 
If one kidney is donated to a needy patient, the other kidney alone is sufficient for removing 
wastes or excretion. Thus, the donor can live a normal life. 
 
 
Question 6: 
In summer the urine is slightly thicker than in winter explain the reason. 
Solution 6: 
During summer, a considerable part of water is lost through perspiration so the kidneys have to 
reabsorb more water from the urine. This makes the urine thicker in summer than in winters. 
 
 
Question 7: 
Differentiate between the following pairs of terms: 
(a) Bowman’s capsule and malpighian capsule. 
(b) Renal cortex and renal medulla 
(c) Renal pelvis and renal papilla 
(d) Urea and urine 
(e) Excretion and katabolism 
Solution 7: 
(a) Bowman's capsule is a thin walled cup containing the glomerulus. This Bowman's capsule 
along with the glomerulus is known as malpighian capsule. 
(b) The renal cortex is the outer darker region of the kidney whereas the renal medulla is the 
inner lighter region of the kidney. 
(c) Renal pelvis is the expanded front end of the ureter in the kidney whereas the renal 
papilla is the apex of the renal pyramid which projects into the pelvis. 
(d) Urea is the chief excretory product which is excreted in the form of urine whereas urine is 
the filtrate left after reabsorption and tubular secretion which contains 95% water and 5% 
solid wastes. 
Class X Chapter 8 – The Excretory System Biology 
______________________________________________________________________________ 
(e) Excretion is the process of removal of chemical wastes especially nitrogenous wastes from 
the body. 
Catabolism on the other hand is the set of metabolic pathways which break down 
molecules into smaller units and release energy. 
 
 
Question 8: 
Name the main nitrogenous metabolic waste excreted out by mammals including humans. 
Solution 8: 
Urea, creatinine, uric acid 
 
 
Question 9: 
Match the terms in Column I with those in Column II and write down the matching pairs. 
Column I Column II  
(a)   Bowman's Capsule Renal artery 
(b)   Contains more CO2 and less   
         urea 
Regulates amount of water 
excreted 
(c)    Anti-diuretic hormone Renal Vein 
(d)   Contains more urea Glomerulus 
Solution 9: 
Column I Column II  
(a)   Bowman's Capsule Glomerulus 
(b)   Contains more CO2 and less  
       urea 
Renal Vein 
(c)    Anti-diuretic hormone 
Regulates amount of water 
excreted 
(d)   Contains more urea Renal artery 
 
 
 
Question 10: 
In a nephron, the ………….. flows through the ………….. under great pressure. The reason for 
this great pressure is that the ………….. (outgoing) ………….. is narrower than the …………..  
(incoming). This high pressure causes the………….. part of the blood to filter out from 
the ………….. into the renal capsule. 
Solution 10: 
In a nephron, the blood flows through the glomerulus under great pressure. The reason for this 
great pressure is that the efferent (outgoing) arteriole is narrower than the afferent