The filtration units of kidneys are called
A. Urethra

B. Ureter

C. Neurons

D. Nephrons

Which is the major nitrogenous waste product in human beings? How is it removed from the body?

Name the process which help in artificial removal of wastes from the body.

Tabulate two differences between renal artery and renal vein.

The diagram given below represents the liver, kidney and some associated blood vessels. Identify the vessel from the labelled parts A-D in which the blood will contain the lowest concentration of urea?

Observe the figure given below which represents the control of water concentration in the blood.

This is a negative feedback

The diagram given below shows the human excretory system.

Identify the function of part labelled as x

There is a pair of bean-shaped organs P in the human body towards the back, just above the waist. A waste product Q formed by the decomposition of unused proteins in the liver is brought into organ P through blood by an artery R. The numerous tiny filters S present in organ P clean the dirty blood by removing the waste product Q. The clean blood goes into circulation through a vein T. The waste substance Q other waste salts, and excess water form a yellowish liquid U which goes from organ P into a bag-like structure V

through two tubes W. This liquid is then thrown out of the body through a tube X.

(a) What is (i) organ P, and (ii) waste substance Q ?

(b) Name (i) artery R; and (ii) vein T.

(c) What are tiny filters S known as?

(d) Name (i) liquid U (ii) structure V (iii) tubes W, and (iv) tube X.

The organs A of a person have been damaged completely due to which too much of a poisonous waste material B has started accumulating in his blood, making it dirty. In order to save this person's life, the blood from an artery in the person's arm is made to flow into long tubes made of substance E which are

kept in coiled form in a tank containing solution F. This solution contains three materials G, H and I in similar proportions to those in normal blood. As the person's blood passes through long tubes of substance E, most of the wastes present in it go into solution. The clean blood is then put back into a vein in the arm of the person for circulation.

(a) What are organs A ?

(b) Name the waste substance B.

(c) What are (i) E, and (ii) F ?

(d) Name G, H and I.

(e) What is the process described above known as?