Question 1. What is excretion? Give names of excretory organs.
When an organism form biochemical reaction in its body cell at reduced various products and by-products some of these products are useful and other waste the waste product must be removed out from the body the process of removing out of the metabolic waste is called excretion.
Some main excretory organs of the body are skin, liver, lungs and kidney.
Question 2. Give names of common excretory products in humans.
Common excretory products in a human body at urea and carbon dioxide.
Question 3. Why the conversion of ammonia to urea is essential in human body?
Because even little levels of ammonia are hazardous, it must be eliminated from the body. In the liver, the urea cycle, also known as the ornithine cycle, ammonia is converted to urea. After then, the urea is carried to the kidneys and expelled.
Question 4. What is the function of a nephron?
The nephron is the kidney’s basic structural and functional unit. By filtering the blood, reabsorbing what is needed, and excreting the excess as urine, it regulates the concentration of water and soluble chemicals like sodium salts
Question 5. Label the diagram given below:
Question 6. What is dialysis?
In person, suffering from renal failure, the blood urea level rises abnormally. Excessive urea in the blood may be dangerous. So to remove urea from the body of such persons, an artificial kidney is used. This mechanism of removing urea, by using an artificial kidney is called dialysis.
Question 7. Name the following:
(i) Animals which excrete ammonia.
(ii) Animals which eliminate urea.
(iii) Animals which excrete uric acid.
(iv) Organ which produces urea.
(v) Functional unit of kidney.
(vi) Organ which stores urine.
(vii) Organ where ultrafiltration occurs.
(i) Animals which excrete ammonia. 1. Ammonotelic.
(ii) Animals which eliminate urea. 2. Ureotelic.
(iii) Animals which excrete uric acid. 3. Uricotelic.
(iv) Organ which produces urea. 4. Liver.
(v) Functional unit of kidney. 5. Nephron.
(vi) Organ which stores urine. 6. UrinaryBladder.
(vii) Organ where ultrafiltration occurs. 7. Glomerulus.
Question 8. Choose the odd one out in the following series:
(i) Proximal convoluted duct, loop of Henle, vein.
(ii) Kidney, ureter, heart
(iii) Urea, uric acid, haemoglobin.
(iv) Glomerulus, alveoli, bronchi.
(v) Renal fat, renal capsule, nerve.
(vi) Column of Bertini, minora calyces, brain.
Question 9. Given below is a diagram of a human kidney, cut open longitudinally. Answer the following:
(i) Give definition of excretion.
(ii) Name the unit of kidney.
(iii) Why does the cortex of kidney show dotted appearance?
(iv) List the functions of the kidney.
1. The process of removal of metabolic wastes from the body is called excretion.
3. Because it contains multiple complex structures called nephrons, the cortex of the kidney has a dotted look.
4. Function of kidney is-
(i) formation of urine
Question 10. Choose the correct answer:
(i) Composition of extracellular fluid is regulated by
(ii) Uric acid is excreted by
(iii) Presence of RBCs in urine is called
(iv) A condition of failure of kidney to form urea is called
(v) What happens if one kidney is removed from the body of human being?
(a) Death due to poisoning
(b) Uraemia and death
(c) Stoppage of urination
(d) Nothing will happen
Nothing will happen
(vi) Orinithin cycle operates in
(d) oral cavity
(vii) Physiologically urea is produced by the action of an enzyme
(viii) Vitamin excreted through urine in mammals is
(a) vitamin A
(b) vitamin C
(c) vitamin D
(d) vitamin K
(ix) Excess proteins are converted into urea in
(x) The smallest functional unit of the kidney is
(b) Bowman’s capsule
(d) collecting tubule
(xi) Narrow apex of pyramid in kidney is called
(b) renal papilla
(c) column of Bertini
(d) duct of Bellini