ICSE Class 10 Biology · Goyal New Approach Biology · 64 solved questions
Exercise
1Test Yourself 1
Write True (T) or False (F):
(i) The liver converts ammonia into urea.
(ii) Kidneys are round, pale yellow organs.
(iii) Bowman's capsule is a cup shaped body present in the cortex part of the kidney.
(iv) Loop of Henle is a U-shaped part of the nephron.
(v) Collecting ducts collect urine from the urinary bladder.
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(i) True
(ii) False Corrected Statement — Kidneys are bean-shaped, reddish brown, slightly flattened organs.
(iii) True
(iv) True
(v) False Corrected Statement — Collecting ducts collect urine from the nephrons.
1Test Yourself 2
Fill in the blanks:
(i) The dark-coloured outer zone of the kidney is called ............... and the pale-coloured inner zone is called ............... .
(ii) Each kidney receives oxygenated blood through a ............... artery.
(iii) The process of control of water balance and ionic concentration within organisms is called ............... .
(iv) The main function of kidney is ............... of ............... compounds.
(v) Reabsorption of useful products takes place in ............... .
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(i) The dark-coloured outer zone of the kidney is called cortex and the pale-coloured inner zone is called medulla.
(ii) Each kidney receives oxygenated blood through a renal artery.
(iii) The process of control of water balance and ionic concentration within organisms is called osmoregulation.
(iv) The main function of kidney is excretion of nitrogenous compounds.
(v) Reabsorption of useful products takes place in renal tubule (proximal convoluted tubule).
2Test Yourself 2
Write down the functional activity of the given organs:
(i) Ureter ...............
(ii) Glomerulus ...............
(iii) Henle's loop ...............
(iv) Renal artery ...............
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(i) Ureter — It carries urine from the kidney to the urinary bladder.
(ii) Glomerulus — It filters the blood by ultrafiltration. Water and small solutes pass from the glomerular blood into Bowman's capsule to form the glomerular filtrate.
(iii) Henle's loop — It absorbs some water and sodium ions and helps in making the urine concentrated.
(iv) Renal artery — It brings oxygenated blood carrying nitrogenous wastes like urea to the kidney for filtration.
1Choose Most Appropriate Answer
The pale yellow colour of normal human urine is due to the pigment
(a)Melanin
(b)Anthocyanin
(c)Urochrome
(d)Haemoglobin
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Urochrome
Reason — The normal pale yellow colour of urine is due to the presence of the pigment urochrome.
2Choose Most Appropriate Answer
In humans, osmoregulation is associated with
(a)Urinary bladder
(b)Liver
(c)Kidney
(d)Blood
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Kidney
Reason — Osmoregulation, the control of water and ionic balance of the body, is brought about by the kidneys.
3Choose Most Appropriate Answer
The Loops of Henle lie in
(a)Renal Cortex
(b)Renal Medulla
(c)Renal Pelvis
(d)Renal Artery
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Renal Medulla
Reason — The loop of Henle is the middle part of the nephron that runs into the medulla and turns back to the cortex.
4Choose Most Appropriate Answer
Assertion (A): The cortex region of kidney is granular in appearance due to the presence of nephrons.
Reason (R): Nephrons are the structural unit of kidneys.
(a)Both (A) and (R) are true
(b)Both (A) and (R) are false
(c)Both (A) and (R) are true and (R) is the correct explanation of (A)
(d)Both (A) and (R) are true but (R) is not the correct explanation of (A)
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Both (A) and (R) are true but (R) is not the correct explanation of (A)
Explanation
The cortex is granular because the Bowman's capsules and convoluted tubules of the nephrons lie in it. The fact that nephrons are the structural unit of the kidney is true, but it does not by itself explain the granular appearance of the cortex.
5Choose Most Appropriate Answer
The inorganic constituent of urine is:
(a)Ammonia
(b)Urea
(c)Creatinine
(d)Uric acid
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Ammonia
Reason — Ammonia is an inorganic nitrogenous waste, whereas urea, creatinine and uric acid are organic nitrogenous wastes.
6Choose Most Appropriate Answer
The nephrons discharge their urine at the
(a)Urinary bladder
(b)Urethra
(c)Renal pelvis
(d)Renal pyramid
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Renal pelvis
Reason — The collecting ducts receive urine from the nephrons and pour it into the renal pelvis.
7Choose Most Appropriate Answer
Choose the correct path of urine in our body.
(a)Kidney → Ureter → Urethra → Urinary bladder
(b)Kidney → Urinary bladder → Urethra → Ureter
(c)Kidney → Ureter → Urinary bladder → Urethra
(d)Urinary bladder → Kidney → Ureter → Urethra
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Kidney → Ureter → Urinary bladder → Urethra
Reason — Urine formed in the kidney passes through the ureter, collects in the urinary bladder, and is finally expelled through the urethra.
8Choose Most Appropriate Answer
During the process of urine formation, different molecules are absorbed from the filtrate. From the list of options given below, identify the molecules which are reabsorbed from filtrate during tubular reabsorption.
A. Water
B. Amino acid
C. Salts
Choose the correct option.
(a)A and B
(b)B and C
(c)A, B and C
(d)Only A
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A, B and C
Reason — During selective reabsorption, water, amino acids and salts are all reabsorbed from the filtrate back into the bloodstream.
9Choose Most Appropriate Answer
Which of the following substances is/are completely reabsorbed from the filtrate in the renal tubule under normal conditions?
(a)Uric acid
(b)Glucose
(c)Salt and water
(d)Urea
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Glucose
Reason — In a normal individual, all of the glucose (along with amino acids) is completely reabsorbed from the filtrate into the blood.
10Choose Most Appropriate Answer
In the glomerulus of a kidney
(a)the afferent glomerular capillaries are wider than the efferent glomerular capillaries
(b)the afferent glomerular capillaries are narrower than the efferent glomerular capillaries
(c)the afferent glomerular arteriole is narrower than the efferent glomerular arteriole
(d)the afferent glomerular arteriole is wider than the efferent glomerular arteriole
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the afferent glomerular arteriole is wider than the efferent glomerular arteriole
Reason — The efferent arteriole is narrower than the afferent arteriole, which builds up the high pressure needed for ultrafiltration.
11Choose Most Appropriate Answer
Assertion (A): There is frequent urination in summer than in winter.
Reason (R): In summer we lose a lot of water as sweat, so the kidneys reabsorb more water. Hence, urine formed is less in summer than in winter.
(a)Both (A) and (R) are true
(b)Both (A) and (R) are false
(c)(A) is true and (R) is false
(d)(A) is false and (R) is true
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(A) is false and (R) is true
Explanation
We urinate fewer times in summer than in winter, so (A) is false. In summer a lot of water is lost as sweat, so the kidneys reabsorb more water and less urine is formed, which makes (R) true.
12Choose Most Appropriate Answer
The diagram given below represents a nephron. Ultrafiltration of blood occurs in:
(a)Bowman’s capsule
(b)Glomerulus
(c)Proximal Convoluted Tubule
(d)Loop of Henle
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Glomerulus
Reason — Ultrafiltration happens in the glomerulus, where blood is filtered to form the filtrate that enters the nephron.
13Choose Most Appropriate Answer
In humans, urea is extracted from blood in
(a)Kidney
(b)Spleen
(c)Ureter
(d)Urinary bladder
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Kidney
Reason — The kidneys extract urea from the blood and excrete it from the body as part of the urine.
14Choose Most Appropriate Answer
Thomas played cricket on a hot summer afternoon. His urine output was much less, though he drank plenty of water. What could be the possible cause?
P - Kidneys reabsorb a lot of water Q - Sweat glands are active R - Kidneys absorb less water S - Sweat glands are inactive
(a)R and Q
(b)P and Q
(c)P and S
(d)R and S
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P and Q
Reason — While playing, the player loses most of water through the sweat glands. Therefore, the kidneys reabsorb most of the water back in the blood to maintain the composition and osmotic pressure of blood. This results in less volume of urine.
15Choose Most Appropriate Answer
Based on the given figure, identify the structural as well as the functional unit of kidney:
(a)A
(b)B
(c)C
(d)D
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C
Reason — The part C in the picture is a nephron. It is the structural and functional unit of kidney.
16Choose Most Appropriate Answer
Bowman's capsule and the glomerulus together are called
(a)Malpighian tubule
(b)Malpighian capsule
(c)Nephron
(d)Uriniferous tubule
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Malpighian capsule
Reason — The Bowman's capsule together with the glomerulus enclosed in it is called the Malpighian capsule.
17Choose Most Appropriate Answer
Ultrafiltration takes place in
(a)Loop of Henle
(b)Bowman's capsule
(c)Glomerulus
(d)Nephrons
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Glomerulus
Reason — In the glomerulus, high blood pressure filters out the liquid part of the blood, so ultrafiltration takes place here.
18Choose Most Appropriate Answer
Anup participated in a marathon race and felt dehydrated by the end of the race. The human body has mechanisms to conserve water and prevent dehydration. Which part of the nephron is primarily responsible for the reabsorption of water to prevent dehydration?
(i) Glomerulus
(ii) Proximal Convoluted Tubule
(iii) Loop of Henle
(iv) Distal Convoluted Tubule
(a)iii
(b)ii and iii
(c)i, ii and iii
(d)ii, iii and iv
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ii, iii and iv
Reason — Water is reabsorbed in the proximal convoluted tubule, the loop of Henle and the distal convoluted tubule, while the glomerulus only filters the blood.
19Choose Most Appropriate Answer
The disease, in which urine contains considerable amount of glucose, is known as
(a)diabetes
(b)dialysis
(c)diarrohea
(d)tetanus
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diabetes
Reason — In diabetes (diabetes mellitus), the body is unable to store excess glucose, so urine contains a considerable amount of glucose.
20Choose Most Appropriate Answer
The structure that stores urine temporarily is
(a)Ureter
(b)Urethra
(c)Urinary bladder
(d)Kidneys
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Urinary bladder
Reason — The urinary bladder is a muscular sac in which urine collects and is stored temporarily.
21Choose Most Appropriate Answer
The main nitrogenous waste formed in the human body is
(a)Uric acid
(b)Urea
(c)Ammonia
(d)Creatinine
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Urea
Reason — Urea is the main nitrogenous waste, formed in the liver from ammonia and excreted by the kidneys.
22Choose Most Appropriate Answer
Priya tried to match the hormones with their effect on the human body. She tabulated the pairs as follows:
Hormone
Effect on the body
P
Stimulates conversion of Glycogen to Glucose
Q
Reabsorption of water by the Nephrons.
Identify the correct pair of hormones.
(a)P-Insulin, Q- Glucagon.
(b)P - Adrenaline, Q - Oxytocin.
(c)P - Glucagon, Q - Vasopressin.
(d)P - Vasopressin, Q - Adrenaline.
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P - Glucagon, Q - Vasopressin.
Reason — Glucagon stimulates the conversion of glycogen to glucose, while vasopressin (ADH) promotes reabsorption of water by the nephrons.
23Choose Most Appropriate Answer
Assertion (A): We urinate more in summer.
Reason (R): Sweat glands are more active in summer.
(a)Both (A) and (R) are true
(b)Both (A) and (R) are false
(c)(A) is true and (R) is false
(d)(A) is false and (R) is true
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(A) is false and (R) is true
Explanation
We urinate fewer times in summer, not more, so (A) is false. Sweat glands are indeed more active in summer, which makes (R) true. Because more water is lost as sweat, the kidneys reabsorb more water and less urine is formed.
24Choose Most Appropriate Answer
Assertion (A): Deficiency of Antidiuretic hormone causes an increase in urination.
Reason (R): Antidiuretic hormone acts on the kidney to reabsorb water from the kidney tubules.
(a)(A) is true and (R) is false.
(b)(A) is false and (R) is true.
(c)Both (A) and (R) are true.
(d)Both (A) and (R) are false.
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Both (A) and (R) are true.
Explanation
Antidiuretic hormone acts on the kidney tubules to reabsorb water. When it is deficient, less water is reabsorbed, so more urine is formed and urination increases. Hence both (A) and (R) are true.
1Very Short Answer Questions
Name the following:
(i) The structural and functional unit of the kidney.
(ii) The duct which carries urine from the urinary bladder to outside the body.
(iii) Knot like mass of blood capillaries inside the Bowman's capsule.
(iv) The organ where urea is produced.
(v) The removal of nitrogenous wastes from the body.
(vi) The vein in which the concentration of urea is maximum.
(vii) Process of maintaining water and salt balance in the blood.
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(i) Nephron
(ii) Urethra
(iii) Glomerulus
(iv) Liver
(v) Excretion
(vi) Hepatic vein
(vii) Osmoregulation
2Very Short Answer Questions
Mark True (T) or False (F) against the following statements and write the false statement:
(i) Bile pigments are formed from the breakdown of haemoglobin of erythrocytes.
(ii) The most poisonous of all waste by-products of metabolism is ammonia.
(iii) The skin plays an excretory role in organisms.
(iv) Liver, the largest gland in the body, is a detoxifying gland.
(v) The left kidney is placed slightly above the right kidney.
(vi) Normal pale yellow colour of the urine is due to the presence of the pigment Melanin.
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(i) True
(ii) True
(iii) True
(iv) True
(v) True
(vi) False Corrected Statement — Normal pale yellow colour of the urine is due to the presence of the pigment urochrome.
3Very Short Answer Questions
Given below are five groups of terms each. In each group arrange and write the items in the correct order so as to be in logical sequence:
Fill in the blanks to make this paragraph meaningful:
Each kidney is made up of ............... main areas—outer ..............., middle medulla and the ............... pelvis. The cortex is granular due to the presence of ............... . Several cone shaped renal ............... extends from the renal cortex to the renal medulla. Each ............... contains around 1 million nephrons.
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Each kidney is made up of three main areas—outer cortex, middle medulla and the renal pelvis. The cortex is granular due to the presence of nephrons. Several cone shaped renal pyramids extends from the renal cortex to the renal medulla. Each kidney contains around 1 million nephrons.
1(i)Short Answer Questions
Define ultrafiltration.
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Ultrafiltration is the mechanical filtration occurring in the glomerulus, in which water and small solutes are filtered out of the blood while blood cells and large molecules like proteins and fats are retained.
1(ii)Short Answer Questions
Define tubular secretion.
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Tubular secretion is the process, reverse of tubular reabsorption, in which the convoluted tubule removes waste materials like uric acid, ammonia, urea, creatinine and drugs from the blood and passes them into the filtrate.
1(iii)Short Answer Questions
Define selective reabsorption.
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Selective reabsorption is the process in which useful materials such as water, glucose, amino acids and some mineral salts are taken back into the bloodstream from the filtrate as it passes through the tubule.
1(iv)Short Answer Questions
Define osmoregulation.
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Osmoregulation is the process of control of water content and concentration of ions in the body.
1(v)Short Answer Questions
Define renal pelvis.
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Renal pelvis is the internal funnel-shaped cavity of the kidney that collects urine from the collecting ducts and leads it into the ureter.
1(vi)Short Answer Questions
Define excretion.
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Excretion is the removal of toxic and unwanted waste products from the body of an organism.
2(i)Short Answer Questions
Give reason — Urine is slightly thicker in summer than in winter.
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In summer, a good amount of water is lost from the body as sweat (perspiration). To conserve water, the kidneys reabsorb more water from the filtrate. As a result, the urine formed is more concentrated and hence slightly thicker in summer than in winter.
2(ii)Short Answer Questions
Give reason — Renal cortex has a dotted appearance and Renal medulla has a striped appearance.
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The Bowman's capsules and the convoluted tubules of the nephrons lie in the cortex, giving it a dotted appearance. The loops of Henle and the collecting ducts run through the medulla, giving it a striped appearance.
2(iii)Short Answer Questions
Give reason — There is frequent urination in winter than in summer.
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In winter, very little water is lost as sweat because sweat glands are less active. Therefore, the kidneys reabsorb less water and more urine is formed, leading to frequent urination in winter than in summer.
2(iv)Short Answer Questions
Give reason — The kidney is composed of number of nephrons.
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Each kidney is composed of about one million nephrons (not neurons). Nephrons, also called uriniferous tubules, are the structural and functional units of the kidney and carry out the formation of urine.
3(i)Short Answer Questions
Differentiate between Cortex and medulla of a kidney.
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Differences between Cortex and medulla of a kidney are:
Cortex
Medulla
It is the outer, dark-coloured, granular region of the kidney.
It is the inner, pale-coloured, striped region of the kidney.
It contains the Bowman's capsules and convoluted tubules of the nephrons.
It contains the loops of Henle, collecting ducts and renal pyramids.
3(ii)Short Answer Questions
Differentiate between Urea and urine.
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Differences between Urea and urine are:
Urea
Urine
It is a single nitrogenous waste compound formed in the liver from ammonia.
It is a liquid excretory product formed by the kidneys.
It is one of the constituents of urine.
It is a mixture of about 95% water and 5% dissolved wastes such as urea, salts and other substances.
3(iii)Short Answer Questions
Differentiate between Renal papilla and renal pelvis.
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Differences between Renal papilla and renal pelvis are:
Renal papilla
Renal pelvis
It is the tip of a renal pyramid that projects into the renal pelvis.
It is the funnel-shaped cavity of the kidney.
Urine drips from the papilla into the pelvis.
It collects the urine and channels it into the ureter.
3(iv)Short Answer Questions
Differentiate between Malpighian capsule and Bowman's capsule.
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Differences between Malpighian capsule and Bowman's capsule are:
Malpighian capsule
Bowman's capsule
It is made up of the Bowman's capsule along with the glomerulus enclosed in it.
It is only the thin-walled, cup-shaped part that encloses the glomerulus.
It is the site of ultrafiltration.
It receives and collects the glomerular filtrate.
3(v)Short Answer Questions
Differentiate between Ureter and Urethra.
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Differences between Ureter and Urethra are:
Ureter
Urethra
It carries urine from the kidney to the urinary bladder.
It carries urine from the urinary bladder to outside the body.
There are two ureters, one from each kidney.
There is only one urethra.
3(vi)Short Answer Questions
Differentiate between Urethra and Uterus.
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Differences between Urethra and Uterus are:
Urethra
Uterus
It is a part of the excretory (urinary) system.
It is a part of the female reproductive system.
It carries urine from the urinary bladder to outside the body.
It is the organ in which the foetus develops.
3(vii)Short Answer Questions
Differentiate between Nephron and Neuron.
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Differences between Nephron and Neuron are:
Nephron
Neuron
It is the structural and functional unit of the kidney.
It is the structural and functional unit of the nervous system.
It is concerned with the formation of urine.
It is concerned with the conduction of nerve impulses.
4Short Answer Questions
Choose the odd one out from the following terms and name the category to which the others belong.
(i) Odd term: Renal artery Category: Others are parts of the internal structure of the kidney.
(ii) Odd term: Keratin Category: Others are constituents of urine.
5Short Answer Questions
Human kidney is a complex organ. Kidneys receive blood through blood vessels which directly branch from the Aorta. Inside each kidney are tiny functional units which filter the blood.
(a) Name the blood vessels that supply blood to the kidneys.
(b) Which are the functional units that filter the blood?
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(a) Renal arteries.
(b) Nephrons
1Long Answer Questions
What is the role of skin, lungs and liver in the process of excretion in human beings?
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The role of skin, lungs and liver in excretion is:
Skin — It excretes urea, salts and excess water by means of the sweat glands present in it.
Lungs — They excrete carbon dioxide and water vapour produced during respiration, which are removed from the surface of the lungs by exhalation.
Liver — It removes urea (by converting ammonia into urea), bile pigments and toxins. It is the largest gland in the body and acts as a detoxifying gland.
2Long Answer Questions
Give the principle involved in the functioning of an artificial kidney machine to clean the blood.
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An artificial kidney machine works on the principle of dialysis. Dialysis is a process of separating small molecules from larger ones using a semipermeable membrane.
Blood from an artery in the arm is passed into the machine, where it flows through a cellulosic dialysis tubing (semipermeable) bathed in a dialysing solution similar to blood plasma but lacking the waste substances. Small waste molecules like urea diffuse out of the blood into the solution and are carried away, while useful substances are retained. The cleaned blood is then returned to the patient through a vein in the same arm.
3Long Answer Questions
Give a brief of wastes excreted out by human.
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The main wastes excreted out by humans are:
CO2 and water — Produced by cells during respiration and eliminated mainly through the lungs.
Nitrogenous wastes — Urea, uric acid and ammonia, produced from proteins mainly in the liver.
Bile pigments — Formed from the breakdown of haemoglobin of dead RBCs; some are excreted in urine.
Excess salts and vitamins — Common salt (NaCl) and some excess water-soluble vitamins are given out mainly by the kidney.
4Long Answer Questions
What remedial measures are followed if a person is showing symptoms of dehydration?
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If a person shows symptoms of dehydration, the following remedial measures are followed:
The person should be given plenty of fluids and water to drink.
Oral Rehydration Solution (ORS), which contains the right balance of salts and sugar, should be given to restore the lost water and ions.
In severe cases, fluids are given intravenously (through a drip) under medical supervision.
The person should rest and avoid heat and strenuous activity that causes further loss of water.
5Long Answer Questions
Mention the three major steps involved in the production of urine.
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The three major steps involved in the production of urine are:
Ultrafiltration — A simple mechanical filtration of blood at the glomerulus.
Selective reabsorption — Reabsorption of useful materials back into the blood, mainly at the proximal convoluted tubule.
Tubular secretion — Removal of remaining wastes from the blood into the filtrate, mainly at the distal convoluted tubule.
6Long Answer Questions
Draw a neat labelled diagram of a Malpighian capsule.
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The labelled diagram of a Malpighian capsule is shown below:
7Long Answer Questions
Draw a neat diagram of a longitudinal section of a human kidney and label Renal Cortex and Renal Medulla on the diagram.
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The labelled diagram of the longitudinal section of a human kidney is shown below:
1Structured Questions
The diagram given below shows a section of a human kidney. Study the diagram carefully and answer the questions that follow:
(i) Label the parts numbered 1 to 4.
(ii) Why does part '2' have a striped appearance?
(iii) What is the fluid that passes down part '4'? Name the main nitrogenous waste present in it.
(iv) Mention the structural and functional units of kidneys.
(v) Name the two major steps in the formation of the fluid mentioned in Q. 5(a) (iii).
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(i) The parts numbered 1 to 4 are:
1 → Cortex
2 → Medulla
3 → Pelvis
4 → Ureter
(ii) The medulla contains Henle's loop and collecting ducts that give it a striped appearance.
(iii) Urine passes down the Ureter. The main nitrogenous waste present in it is Urea.
(iv) Nephrons (also called uriniferous tubules, renal tubules, kidney tubules)
(v) The two major steps are —
Ultrafiltration
Selective Reabsorption.
2Structured Questions
The given diagram represents a nephron and its blood supply. Study the diagram and answer the following questions:
(i) Label parts 1, 2, 3 and 4.
(ii) State the reason for the high hydrostatic pressure in the glomerulus.
(iii) Name the blood vessel which contains the least amount of urea in this diagram.
(iv) Name the two main stages of urine formation.
(v) Name the part of the nephron which lies in the renal medulla.
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(i) The parts 1, 2, 3 and 4 are:
1 → Collecting duct.
2 → Distal convoluted tubule.
3 → Loop of Henle.
4 → Bowman's capsule.
(ii) The efferent arteriole is narrower than the afferent arteriole. This creates a high hydrostatic pressure in the glomerulus.
(iii) Renal vein (part 6).
(iv) Two main stages of urine formation are:
Ultrafiltration.
Selective Reabsorption.
(v) Loop of Henle
3Structured Questions
Study the diagram given below and then answer the questions that follow:
(i) Name the region in the kidney where the above structure is present.
(ii) Name the parts labelled 1, 2, 3 and 4.
(iii) Name the stages involved in the formation of urine.
(iv) What is the technical term given to the process occurring in 2 and 3? Briefly describe the process.
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(i) The structure is a Malpighian capsule, which is present in the cortex of the kidney.
(ii) The parts labelled 1-4 are:
1 → Afferent arteriole
2 → Glomerulus
3 → Bowman's capsule
4 → Efferent arteriole
(iii) Urine formation involves three stages:
Ultrafiltration
Selective reabsorption
Tubular secretion
(iv) The process occurring in 2 and 3 is called Ultrafiltration. The blood flows through the glomerulus under great pressure because the efferent arteriole is narrower than the afferent arteriole. This high pressure causes the liquid part of the blood, along with water, salts, glucose and nitrogenous wastes, to filter out from the glomerulus into the Bowman's capsule, while blood cells and large molecules like proteins are retained. This filtration under great pressure is called ultrafiltration.
4Structured Questions
The diagram given below shows the excretory system of a human being. Study the same and then answer the questions that follow—
Reason — Posterior vena cava carries deoxygenated blood from the lower parts of the body back to the heart. Aorta is the largest artery that carries oxygenated blood from the heart to different body parts, including the kidneys. Renal artery carries oxygenated blood containing nitrogenous wastes from the aorta to the kidneys for filtration. Renal vein carries filtered blood away from the kidneys and joins the posterior vena cava.
(ii) Which part carry urine from kidney to urinary bladder
Aorta
Urethra
Ureter
Renal tubule
Ureter
Reason — The ureter is a muscular tube that transports urine from each kidney to the urinary bladder for temporary storage. Aorta is a blood vessel that carries oxygenated blood from the heart, not urine. Urethra carries urine from the urinary bladder to the outside of the body, not from kidney to bladder. Renal tubules help in filtration, reabsorption, and urine formation inside the kidney but do not transport urine to the bladder.
(iii) The name of part 8 is
Ureter
Urethra
Uterus
None of these
Urethra
(iv) Which endocrine gland could be added in the diagram
Pituitary gland
Thyroid gland
Parathyroid gland
Adrenal gland
Adrenal gland
Reason — The adrenal glands are located on top of the kidneys and secrete hormones like adrenaline and aldosterone. Since they are associated with the kidneys, they can be added to the excretory system diagram. The pituitary gland is located at the base of the brain and controls many other endocrine glands; it is not associated with the kidneys. The thyroid gland is located in the neck region and regulates metabolism; it is not attached to the kidneys. The parathyroid glands are present behind the thyroid gland and regulate calcium levels; they are not related to the excretory system.
5Structured Questions
The diagram given below is that of a structure present in a human kidney. Study the same and answer the questions that follow:
(i) Name the structure represented in the diagram.
(ii) What is the liquid entering part '1' called? Name two substances present in this liquid that are reabsorbed in the tubule.
(iii) What is the fluid that comes to part '2' called? Name the main nitrogenous waste in it.
(iv) Mention the three main steps involved in the formation of the fluid mentioned in (iii) above.
(v) Name the substance which may be present in the fluid in part '2' if a person suffers from Diabetes mellitus.
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(i) The structure represented in the diagram is that of Nephron.
(ii) The liquid entering part 1 is called Glomerular filtrate which is formed by the ultrafiltration of blood through glomerulus. The two substances present in this liquid are — Glucose and Water.
(iii) The fluid that comes to part 2 is called urine. The main nitrogenous waste in urine is Urea.
(iv) The three main steps involved in the formation of urine are:
Ultrafiltration
Selective reabsorption
Tubular secretion.
(v) If a person suffers from diabetes mellitus Glucose will be present in the urine.
6Structured Questions
The diagram given below represents an organ system in the human body. Study the same and answer the questions that follow:
(i) Identify the system of human.
(ii) Label the parts marked 3 and 6. Mention the function of part 6.
(iii) Name the structural and functional unit of the part marked 9.
(iv) What is the fluid that accumulates in part 6? Which is the main nitrogenous waste present in it?
(v) Draw a neat, labelled diagram showing the longitudinal section of part 9.
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(i) It is the excretory (urinary) system of humans.
(ii) The parts marked are:
3 → Renal artery
6 → Urinary bladder
Function of part 6 (Urinary bladder) — It is a muscular sac that stores urine temporarily until it is expelled from the body.
(iii) The part marked 9 is the kidney, and its structural and functional unit is the nephron.
(iv) The fluid that accumulates in part 6 (urinary bladder) is urine, and the main nitrogenous waste present in it is urea.
(v) The labelled diagram of the longitudinal section of part 9 (kidney) is shown below:
