{"id":15875,"date":"2022-05-13T23:00:29","date_gmt":"2022-05-13T17:30:29","guid":{"rendered":"https:\/\/cbselibrary.com\/?p=15875"},"modified":"2023-11-10T12:08:11","modified_gmt":"2023-11-10T06:38:11","slug":"selina-icse-solutions-class-10-biology-excretory-system-elimination-body-wastes","status":"publish","type":"post","link":"https:\/\/cbselibrary.com\/selina-icse-solutions-class-10-biology-excretory-system-elimination-body-wastes\/","title":{"rendered":"Selina Concise Biology Class 10 ICSE Solutions The Excretory System (Elimination of Body Wastes)"},"content":{"rendered":"

Selina Concise Biology Class 10 ICSE Solutions The Excretory System (Elimination of Body Wastes)<\/span><\/h2>\n

APlusTopper.com provides step by step solutions for Selina Concise ICSE Solutions for Class 10 Biology Chapter 8 The Excretory System (Elimination of Body Wastes). You can download the Selina Concise Biology ICSE Solutions for Class 10 with Free PDF download option. Selina Publishers Concise Biology for Class 10 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.<\/p>\n

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Selina ICSE Solutions for Class 10 Biology Chapter 8 The Excretory System (Elimination of Body Wastes)<\/strong><\/p>\n

Exercise 1<\/strong><\/span><\/p>\n

Solution A.1.<\/strong><\/span>
\n(c) Removal of nitrogenous wastes<\/p>\n

Solution A.2.<\/strong><\/span>
\n(a) Proximal convoluted tubule<\/p>\n

Solution A.3.<\/strong><\/span>
\n(c) Sweating<\/p>\n

Solution A.4.<\/strong><\/span>
\nLiver<\/p>\n

Solution B.1.<\/strong><\/span>
\n(a) Liver
\n(b) Cortex
\n(c) Glomerulus
\n(d) Collecting duct
\n(e) Renal artery (Renal vein has urea but renal artery has higher concentration of urea as compared to renal vein).<\/p>\n

Solution B.2.<\/strong><\/span>
\n(a) Afferent arteriole, glomerulus, efferent arteriole, capillary network, renal vein
\n(b) Renal artery, kidney, ureter, urinary bladder, urethra<\/p>\n

Solution B.3.<\/strong><\/span>
\n(a) Ultrafiltration
\n(b) Excretion
\n(c) Osmoregulation
\n(d) Excretion<\/p>\n

Solution C.1.
\n<\/strong><\/span>(a) Glomerulus<\/strong>\u00a0is 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.
\n(b) Henle’s loop<\/strong>\u00a0is involved in reabsorption of water and sodium ions.
\n(c) Ureter<\/strong>\u00a0carries urine to the urinary bladder by ureteral peristalsis.
\n(d) Renal artery<\/strong>\u00a0supplied blood to the kidney.
\n(e) Urethra<\/strong>\u00a0is involved in the process of micturition i.e. expelling urine out of the body.<\/p>\n

Solution C.2.<\/strong><\/span>
\nExcretion 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.
\nCarbon dioxide, water, nitrogenous compounds such as urea, uric acid and excess salts are some common excretory products.<\/p>\n

Solution C.3.<\/strong><\/span>
\nA uriniferous tubule also known as the kidney tubule is the structural and functional unit of the kidney.
\nIt 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.<\/p>\n

Solution C.4.<\/strong><\/span>
\nMaintaining 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.<\/p>\n

Solution C.5.<\/strong><\/span>
\nIf 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.<\/p>\n

Solution C.6.<\/strong><\/span>
\nDuring 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.<\/p>\n

Solution C.7.<\/strong><\/span><\/p>\n

(a) Bowman’s capsule<\/strong>\u00a0is a thin walled cup containing the glomerulus. This Bowman’s capsule along with the glomerulus is known as\u00a0malpighian capsule<\/strong>.<\/p>\n

(b) The\u00a0renal cortex<\/strong>\u00a0is the outer darker region of the kidney whereas the\u00a0renal medulla<\/strong>\u00a0is the inner lighter region of the kidney.<\/p>\n

(c) Renal pelvis<\/strong>\u00a0is the expanded front end of the ureter in the kidney whereas the\u00a0renal papilla\u00a0<\/strong>is the apex of the renal pyramid which projects into the pelvis.<\/p>\n

(d) Urea<\/strong>\u00a0is the chief excretory product which is excreted in the form of urine whereas\u00a0urine<\/strong>\u00a0is the filtrate left after reabsorption and tubular secretion which contains 95% water and 5% solid wastes.<\/p>\n

(e) Excretion<\/strong>\u00a0is the process of removal of chemical wastes especially nitrogenous wastes from the body.
\nCatabolism\u00a0<\/strong>on the other hand is the set of metabolic pathways which break down molecules into smaller units and release energy.<\/p>\n

Solution C.8.<\/strong><\/span>
\nUrea, creatinine, uric acid<\/p>\n

Solution C.9.<\/strong><\/span><\/p>\n\n\n\n\n\n\n\n
Column I<\/strong><\/td>\nColumn II\u00a0<\/strong><\/td>\n<\/tr>\n
(a)\u00a0\u00a0 Bowman’s Capsule<\/td>\nGlomerulus<\/td>\n<\/tr>\n
(b)\u00a0\u00a0 Contains more CO2<\/sub>\u00a0and less urea<\/td>\nRenal Vein<\/td>\n<\/tr>\n
(c)\u00a0\u00a0\u00a0 Anti-diuretic hormone<\/td>\nRegulates amount of water excreted<\/td>\n<\/tr>\n
(d)\u00a0\u00a0 Contains more urea<\/td>\nRenal artery<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Solution C.10.<\/strong><\/span>
\nIn a nephron<\/a>, the\u00a0blood\u00a0flows through the\u00a0glomerulus\u00a0under great pressure. The reason for this great pressure is that the\u00a0efferent\u00a0(outgoing)\u00a0arteriole\u00a0is narrower than the\u00a0afferent arteriole\u00a0(incoming). This high pressure causes the\u00a0liquid\u00a0part of the blood to filter out from the\u00a0glomerulusinto the renal capsule.<\/p>\n

Solution D.1.<\/strong><\/span><\/p>\n

(a)\u00a0Ultrafiltration –<\/strong>\u00a0The process of the filtration of blood in the glomerulus under great pressure during which the liquid part of the blood i.e. plasma along with urea, glucose, amino acids and other substances enter the renal tubule.<\/p>\n

(b)\u00a0Micturition –<\/strong>\u00a0The process of expelling urine out of the body through urethra by opening the sphincter muscles passing of urine involving relaxation of sphincter muscles between the urinary bladder and urethra.<\/p>\n

(c)\u00a0Renal pelvis\u00a0–\u00a0<\/strong>Renal pelvis is the expanded front end of the ureters into the kidney.
\n<\/strong><\/p>\n

(d)\u00a0Urea\u00a0–\u00a0<\/strong>A nitrogenous waste produced primarily in the liver due to the break down dead protein remains and extra amino acids.<\/p>\n

(e)\u00a0Osmoregulation<\/strong>\u00a0–\u00a0<\/strong>It is a process of maintaining the blood composition of the body i.e. the normal osmotic concentration of water and salts in the body.<\/p>\n

Solution D.2.<\/strong><\/span><\/p>\n

Ultrafiltration –<\/strong>\u00a0Ultrafiltration involves filtration of the blood which takes place in the glomerulus. The blood containing urea from the afferent arteriole enters the glomerulus under high pressure. The high pressure is created because the efferent arteriole is narrower than the afferent arteriole. The high pressure causes the liquid part of the blood to filter out from the glomerulus into the renal tubule. This filtrate is known as ‘glomerular filtrate’.
\nGlomerular filtrate consists of water, urea, salts, glucose and other plasma solutes. Blood corpuscles, proteins and other large molecules remain behind in the glomerulus. Therefore the blood which is carried away by the efferent arteriole is relatively thick.<\/p>\n

Selective absorption –\u00a0<\/strong>The Glomerular filtrate entering the renal tubule contains a lot of usable materials such as glucose and sodium. As this filtrate passes down the renal tubule, a lot of water along with these usable materials is reabsorbed. Such reabsorption is called ‘selective absorption’. The reabsorption occurs only to the extent that the normal concentration of the blood is undisturbed.<\/p>\n

Solution D.3.
\n<\/strong><\/span>Dialysis<\/strong>\u00a0involves the use of artificial kidney or a dialysis machine. The patient’s blood is from the radial artery is led through the machine where excess salts and urea is removed. The purified blood is then returned to a vein in the same arm.
\nDialysis is carried out in case of failure of both the kidneys. In case there is a permanent damage, then the dialysis is to be repeated for about 12 hours twice a week.<\/p>\n

Solution E.1.<\/strong><\/span>
\n(a) The image shown can be left or right kidney. As the right kidney is slightly lower than the left one, so we need to have the images of both the kidneys for comparison.
\n(b) It is a longitudinal section of the kidney.
\n(c) 1-renal artery, 2-renal vein, 3-ureter, 4-cortex, 5-pelvis
\n(d) (i) 4\/cortex
\n(ii) medulla
\n(iii) 5\/pelvis<\/p>\n

Solution E.2.<\/strong><\/span>
\n(a) Excretory system and Circulatory system.
\n(b) 1-kidney, 2-renal artery, 3-ureter, 4-urinary bladder, 5-urethera
\n(c) Nephron
\n(d) Urea and ammonia
\n(e) Ultrafiltration and selective reabsorption<\/p>\n

Solution E.3.<\/strong><\/span>
\n(a) 4\/Glomerulus
\n(b) 2\/Efferent arteriole
\n(c) 1\/ Afferent arteriole from renal artery
\n(d) 7\/Collecting tubule
\n(e) 5\/ Proximal convoluted tubule with blood capillaries<\/p>\n

Solution E.4.<\/strong><\/span>
\n(a) The process of removal of chemical wastes especially nitrogenous waste from the body is known as excretion.
\n(b) Nephrons
\n(c) As the cortex region contains numerous nephrons or kidney tubules, therefore, it shows a dotted appearance.
\n(d) Kidneys help in removing wastes or excretion and osmoregulation.
\n(e) The blood vessel ‘B’ is renal artery and the blood vessel ‘A’ is renal vein.<\/p>\n

So the blood vessel ‘B’ contains oxygenated blood with high concentration of urea and glucose whereas the blood vessel ‘A’ contains deoxygenated blood with low concentration of urea and glucose as compared to renal artery.<\/p>\n

Solution E.5.<\/strong><\/span>
\na. The structure is a Bowman’s capsule, which is part of the nephron. The Bowman’s capsule is found in the cortex of the kidney.<\/p>\n

b.<\/p>\n

    \n
  1. Afferent arteriole<\/li>\n
  2. Glomerulus<\/li>\n
  3. Bowman’s capsule<\/li>\n
  4. Efferent arteriole<\/li>\n<\/ol>\n

    c. Urine formation occurs in two steps – ultrafiltration and reabsorption.<\/p>\n

    d. The process occurring in 2 and 3 is known as ultrafiltration.
    \nIn the glomerulus, the blood flows under high pressure because of the narrow lumen of the capillary network of the glomerulus. This forces most of the components (both waste and useable materials) of the blood out of the capillaries. This process of the filtration of blood under high pressure in the Bowman’s capsule is known as ultrafiltration.<\/p>\n

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