Kidneys help to regulate the volume of fluid and various metabolites waste products in the body. Normally,…
Kidneys help to regulate the volume of fluid and various metabolites waste products in the body.
Normally, kidney filter about 180 L of fluid daily but the volume actually excreted out is only a litre or two a day.
Patients with kidney failures can be saved by dialysis and kidney transplant.
(a) Write the structure and function of Bowman's capsule. [1]
(b) Although kidneys filter a large amount (about 180 L daily) of fluids, still the excretion from the body is only about a litre or two. Why ? [1]
(c) What is excretion ? Why is it necessary for any living organism ? [2]
Solution
(a)
• Structure → Bowman’s capsule is a cup shaped end of a
coiled tube (nephron)
• Function → Bowman’s capsule collects the filtrate from
the blood.
(b) Most of the water, salt, glucose, amino acids are
selectively reabsorbed from the filtrate into the blood as
the urine flows along the tubular part of nephron.
(c)
• Excretion is the process of removal of metabolic wastes/
nitrogenous waste/ urea/uric acid from the body.
• It is essential for survival of a living organism as the
excretory products are toxic and harmful to the organism.
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OR
(c)
• Both lungs and kidneys remove metabolic waste /
Lungs remove carbon dioxide gas (CO2) from the
blood while kidneys remove nitrogenous wastes like
urea from the blood.
• Both lungs and kidneys have thin-walled blood capillaries
involved in exchange of gases and filtration of blood
respectively.