The proximal convoluted tubule is lined by the:
1. Simple cuboidal epithelium
2. Simple columnar epithelium
3. Simple cuboidal brush bordered epithelium
4. Simple columnar brush bordered epithelium

During the concentration of urine by the human kidneys, NaCl is returned to the medullary interstitium by the:

1. Descending limb of the loop of Henle

2. Ascending limb of the loop of Henle

3. Descending limb of the vasa recta

4. Ascending limb of the vasa recta

Identify the correct statement regarding the excretion of acids by the human kidney :
1. The filtered bicarbonate is absorbed by anion transport
2. The intercalated cells of the distal tubule secrete hydrogen ions to reabsorb bicarbonate from the tubular fluid.
3. All of the filtered bicarbonate is normally reabsorbed in the first half of the distal tubule.
4. Urine pH is normally greater than that of plasma.

Blood doping means use of banned substances by athletes that have a favorable effect on erythrocyte count by stimulating the bone marrow. The source of such a hormone can be the human:

1. Spleen

2. Heart 

3. Kidney

4. Lungs

The main disadvantage of urea as an excretory product for animals eliminating it would be:

1. its high toxicity

2. Needs lot of water to be eliminated

3. It being an osmolyte

4. Energy expenditure to produce it

Match each item in Column I with one in Column II and choose the correct option from the codes given below:

            A      B      C

 1.        b      d      f

 2.        a      d      f

 3.        a      c      e

 4.        b      d      e

Excretion of dilute urine requires

 1.   relative permeability of the distal tubule to water

 2.   transport of sodium and chloride ions out of the descending loop of Henle

 3.   the presence of ADH

 4.   impermeability of the collecting tubule to water

The condition where urea accumulates in blood is: 

1. Glycosuria

2. Uremia

3. Ketonuria

4. Acidosis

Juxtaglomerular apparatus is a special sensitive region formed by cellular modifications in the:

1. DCT and Efferent arteriole at the point of their contact

2. DCT and the Afferent arteriole at the point of their contact

3. PCT and Afferent arteriole at the point of their contact

4. PCT and Efferent arteriole at the point of their contact

Which of the following statements about the kidneys is incorrect?

1. They consume over 20% of the oxygens used by the body at rest.

2. Approximately 1200ml of fluid is filtrated by the kidneys each day.

3. 120-125 ml of plasma is forced into the renal tubules each minute.

4. They compose less than 1% of the body weight.