Reabsorption of useful substances from glomerular filtrate occurs in 
From Bowman's capsule, glomer ular filtrate enters the proximal convolute tubule. Most of the useful substances like Glucose (all), Amino Acids (all), most of the inorganic ions (Na+, K+, Cl– etc), most of the important buffer bicarbonates are reabsorbed in Proximal Convoluted Tubule. Cells are specially adaptive for absorption having numerous microvilli & mitochondria (to provide energy for active absorption).
Brush border is characteristic of 
Proximal convoluted tubule (PCT) is lined by simple cuboidal brush border epithelium. The brush border epithelium increases the surface area for reabsorption. Nearly all of the essential nutrients, and 70-80 percent of electrolytes. Hence brush border is characteristic of the proximal convoluted tubule.
So, the correct answer is 'Proximal convoluted tubule'.
Proximal and distal convoluted tubules are parts of 
Nephron is the excretory unit of human excretory system. Each nephron has a Bowman’s Capsule, a Proximal Convoluted Tubule (PCT), Loop of Henle (Descending & Ascending limbs) and Distal Convoluted Tubule (DCT) which then enter into collecting duct.
Under normal conditions which one is completely reabsorbed in the renal tubule? 
The cells of Proximal Convoluted Tubule (PCT) reabsorb entire glucose, amino acids, most of the inorganic ions (Na+, K+, Cl–) much of the water as well as some urea. Glucose is reabsorbed actively and most effectively.
Nitrogenous waste products are eliminated mainly as 
Ammonia molecules are small and very soluble in water. In ammonotelic animals large amount of H2O is required to eliminate ammonia from the body, so it is found in aquatic animals like tadpole of frog. When tadpole becomes a mature frog it acquires mainly ureotelism.
Glucose is taken back from glomerular filtrate through 
Hair present in the skin are 
Each hair is present in a tubular pit called hair follicle. Living cells are only present at the base of hair known as hair papilla, rest of the hair is dead and divisible into outer cuticle, middle cortex & inner medulla.
Part not belonging to uriniferous tubule is
The uriniferous tubule or the kidney tubule is a fine, long, convoluted tubule that is involved in excretory functions. This tubule basically conveys urine from the glomerulus to the renal pelvis. A large amount of water and salts are reabsorbed during the passage of urine through it At certain locations in the kidney tubule, some ions are also secreted into the urine. It includes the Henle's loop, the DCT and PCT, and the collecting tubule.
So, the correct answer is 'Glomerulus'.
If kidney fail to reabsorb water, the effect on tissue would 
If kidneys fail to reabsorb water the urine will be diluted causing polyuria (frequent urination). Then the body tissues get dehydrated & the cell will loose water content & shrink.
Uric acid is nitrogenous waste in 
The excretion of uric acidis called uricotelism. The excretion of uric acid is advantageous for those animals which have to conserve water for their survival like birds and lizards.
A patient suffering from cholera is given saline drip because [1996, 2000]
In patients affected with cholera, a cholera enterotoxin is produced which results in increased synthesis of intracellular cyclic AMP, which in turn increases the permeability of intestinal mucosa, leading to secretion of fluid throughout the small intestine. Hence the patient is given saline drip whereby Na+ ions restore the osmotic balance by retaining water in the body.
In Or nithine cycle, which one pair of the following wastes are removed from the blood?
In ureotelic animals urea is formed from ammonia by Ornithine cycle.
In ureotelic animals, urea is formed by the [1997, 2000]
In ureotelic animals urea is formed by Ornithine cycle. Urea is formed in the liver where two molecules of ammonia combine with one molecule of CO2 in presence of Ornithine, citrulline, arginine and enzyme arginase. This is called Ornithine cycle.
The basic functional unit of the human kidney is
Nephridia are the excretor y str uctures of annelids. Henle's loop is a part of the nephron or uriniferous tubule of the vertebrate kidney.
Solenocytes are the main excretory structures in
Solenocytes or flame cells or protonephridia are excretory organs in Platyhelminthes (Flatworms). They excrete ammonia. In Annelids excretory structure are nephridia. In Molluscs sac like kidneys are excretory. In Echinodermata nitrogenous wastes are excreted through gills.
In the renal tubules the permeability of the distal convoluted tubule and collecting duct to water is controlled by 
Growth hormone, released by the anterior lobe of pituitary brings about body growth by synthesis and deposition of proteins in tissues. Renin secreted by special cells in kidneys regulates blood pressure. Aldosterone reduces Na+ elimination by helping active reabsorption from the nephric filtrate.
Formation of concentrated (hyperosmotic) urine in vertebrates generally depends on 
Henle’s loop is involved in osmoregulation and concentrating urine. Thus producing a hypertonic urine.
The enteronephric nephridia of earthworm are concerned with 
The nephridia are the excretory organs. The nephridia in earthworm are – Septal nephridia, Pharyngeal nephridia and Integumentary nephridia. The septal nephridia do not discharge excretory fluid to the exterior rather it pour them into the intestine. Hence these are also called Enteronephric nephridia.
Which one of the following is a matching pair?
Sweat regulates body temperature. Sweating also called perspiration or sometimes transpiration is the production and evaporation of a fluid, consisting primarily of water as well as a smaller amount of sodium chloride the main constituent of “table salt”, that is excreted by the sweat glands in the skin of mammals.
In Hydra waste material of food digestion and nitrogenous waste material removed from
Hydra being a coelenterate, has blind sac body plan. It has only one mouth which serves as the opening for ingestion and waste elimination besides diffusion across body wall.
If Henle's loop were absent from mammalian nephron, which of the following is to be expected? 
Henle’s loop is associated with the concentration of urine and production of hypertonic urine.
When a fresh-water protozoan possessing a contractile vacuole, is placed in a glass containing marine water, the vacuole will 
Fresh water protozoans live in hypotonic solution so, for regulation of excess of water which comes in the protoplasm through the process of endosmosis, contractile vacuoles have developed, When these protozoans are placed in marine water i.e., hypertonic water, the contractile vacuoles become disappear because the process of endosmosis does not happen and thus, water does not come in the protoplasm.
Uricotelism is found in 
In uricotelic animals nitrogenous waste is eliminated in the form of uric acid. Ammonotelism is seen in aquatic animals wherein nitrogenous wastes is eliminated in the form of ammonia eg. Fishes, tadpole. Ureotelism is observed in human beings in which nitogenous waste is eliminated as urea.
A terrestrial animal must be able to 
Terrestial animals have limited access to water. Hence they have to secrete hypertonic urine and conserve water. Choices (c) and (d) are characteristics of marine animals who need to overcome the problem of preventing entry of salts and loss of water. Choice (a) is characteristic of fresh water animals.
A person is undergoing prolonged fasting. His urine will be found to contain abnormal quantities of: 
If a person is undergoing prolonged fasting, his urine will be found to contain abnormal quantities of ketones. During fasting energy is obtained by the oxidation of reserved fats. As a result of fatty acid oxidation large amount of ketone bodies are produced such as acetoacetate, (3-hydroxybutyrate and acetone.