The net pressure gradient that causes the fluid to filter out of the glomeruli into the capsule is:
(i) Glomerular capillary pressure (45 mm Hg) favours filteration. (ii) The colloidal osmotic pressure (due to plasma proteins, particularly albumin) acts against filteration. Its value is ~20 mmHg. (iii) The filterate pressure due to the glomerular filterate filled in the Bowman’s capsule also acts against filteration. Its value is ~10 mmHg.
Net filteration pressure = 45 – (20 + 10) mm Hg = 15 mm of Hg (10 – 20 mm of Hg)
In Ornithine cycle, which of the following wastes are removed from the blood? 
Urea NH2 – CO – NH2 is formed from two molecules of ammonia and one molecule of carbon dioxide. A molecule of ammonia combines with carbondioxide to form carbonyl phosphate. It reacts with ornithine to form citrulline. Citrulline accepts another molecule of NH4+ giving rise to arginine. Arginine is hydrolysed into urea and ornithine with the help of enzyme arginase.
Earthworms are 
Some animals have dual behaviour of excretion eg. earthworm. It excretes ammonia (hence called ammonotelic) when enough water is available but excretes urea (ureotelic) in dry conditions.
Bowman’s glands are located in the anterior pituitary 
Bowman’s gland sare located in the olfactory epithelium of our nose.
Lysozyme that is present in perspiration, saliva and tears, destroys 
Lysozyme is an antibacterial agent which is secreted by the major salivary glands.
Consider the following four statements (a-d) about certain desert animals such as kangaroo, rat.
(a) They have dark colour and high rate of reproduction and excrete solid urine
(b) They do not drink water, breathe at a slow rate to conserve water and have their body covered with thick hairs
(c) They feed on dry seeds and do not require drinking water
(d) They excrete very concentrated urine and do not use water to regulate body temperature
Which two of the above statements for such animals are true? 
Characteristics of certain desert animals such as kangaroo, rat are -
What will happen if the stretch receptors of the urinary bladder wall are totally removed ?
The stretch receptors basically function by sending signal to the brain. After receiving the signal it relaxes the bladder so that the urine passes out. In case the stretch receptors are removed or damaged, they would not be able to send the apt signal and hence would remain closed leading to no micturition.
Uric acid is the chief nitrogenous component of the excretory products of 
Uric acid is the chief nitrogenous component of the excretory product of cockroach. Animals which live in dry conditions have to conserve water in their bodies. Therefore, they synthesise crystals of uric acid trom ammonia. Uric acid crystals are non-toxic and can be retained in the body for a considerable time. Uricotelic animals include most insects e.g. cockroach, reptiles and birds.
Which one of the following statements in regard to the excretion by the human kidneys is correct? 
Urine formation involves three main process called, glomerular filtration, reabsorption and secretion. A comparison of the volume of the filtrate formed per day (which is 180 litres per day) with that of urine released (about 1.5 litres) suggest that nearly 99 percent of the glomerular filtrate is resorbed by the renal tubules. The descending limb of loop of Henle is permeable to water but impermeable to electrolytes.
The ascending limb is impermeable to water but allows transport of electrolytes.
Reabsorption of sodium ions and water takes place in distal convoluted tubule.
Also, it is capable of reabsorption of HCO3.
The principal nitrogenous excretory compound in humans is synthesised 
The principal nitrogenous excretory compound in humans is urea. It is synthesized in the mitrochondrial matrix and cytosol of liver cells and eliminated through kidneys.
Consider the following four statements (i-iv) regarding kidney transplant and select the two correct ones out of these. 
(i) Even if a kidney transplant is proper the recipient may need to take immune suppresants for a long time
(ii) The cell mediated immune response is responsible for the graft rejection
iii) The B lymphocytes are responsible for rejection of the graft
(iv) The acceptance or rejection of a kidney transplant depends on specific interferons
The two correct statements are:
Tissue and blood group matching are essential before undertaking kidney transplant. Even if kidney transplant is proper, the recipient may need to take immuno suppresant all his/her life. The ability of body to differentiate self and nonself and the cell-mediated immune response is responsible for graft rejection.
Which one of the following is not a part of a renal pelvis? 
A large proportion of oxygen is left unused in the human blood even after its uptake by the body tissues. This O2 
A large portion of oxygen is left unused in the human blood even after its uptake by the body tissues. This O2 acts as a reserve during muscular exercise.
Which one of the following correctly explains the function of a specific part of a human nephron ? 
Glome podocytes are highly specialized cells with a complex cytoarchitecture plays a major role in establishing the selective permeability of glomerular filtration barrier.
Which one of the following statements is correct with respect to kidney function regulation ? 
When some one drinks lots of water, kidney release of ADH is suppressed.
Uricotelic mode of passing out nitrogenous wastes is found in 
An uricotelic organism produces uric acid as a result of de-amination. Examples of such organism are birds and insects.
Ureters act as urogenital ducts in [2011M]
In male frogs the sper ms are car ried through the ureters, hence in male, ureters are called urinogenital ducts.
The maximum amount of electrolytes and water (70 - 80 percent) from the glomerular filtrate is reabsorbed in which part of the nephron ? 
Nearly all the essential nutrients, and 70-80 percent of electrolytes and H2O are reabsorbed by proximal convoluted tubules.
Which one of the following options gives the correct categorization of six animals according to the type of nitrogenous wastes (A, B, C), they give out? [2012M]
Those animals that excrete ammonia are called as ammonotelic, eg. aquatic amphibia. Those animals that excrete urea are called as ureotelic, eg. frog, humans.
Those animals that excrete uric acid are called as uricotelic, eg. pigeon, lizards, and cockroach.
A fall in glomer ular filtration rate (GFR) activates [2012M]
The amount of the filtrate formed by the kidneys per minute is called glomerular filtration rate (GFR). GFR in a healthy individual is approximately 125 ml/ minute, i.e., 180 litres per day. A fall in GFR can activate the JG cells to release renin which can stimulate the glomerular blood flow and thereby the GFR back to normal. Renin converts angiotensinogen in blood to angiotensin I and further angiotensin II. Angiotensin II being powerful vasoconstrictor increases the glomerular blood pressure and thereby GFR
Which one of the following characteristics is common to both in humans and adult frogs? [2012M]
Adult frog and human exhibit ureotelism because there excretory waste product is urea.
Figure shown human urinar y system with structures labelled A to D. Select option which correctly identifies them and gives their characteristics and /or functions. [NEET 2013]
A – Adrenal gland – located at the anterior part of kidney, secrete Catecholamines which stimulate glycogen breakdown.
Select the option which shows correct matching of animal with excretory organs and excretory product [NEET Kar. 2013]
Option ( c) is correct answer.
As Housefly - Malpigian Tubules - Uric acid
Rohu - Kidney - Ammonia
Peacock - Kidney - Uric acid
Salamander - Kidney - Urea