What is true of urea biosynthesis?
1. Uric acid is the starting point
2. Urea is synthesized in lysosomes
3. Urea cycle enzymes are located inside mitochondria
4. Urea is synthesized in the kidney

Consider the following statements:
 

Which of the above statements are true?
1. I and II only         
2. I and III only
3. II and III only       
4. I, II, and III

Consider the following statements:
I. The DCTs of many nephrons open into the collecting duct.
II. In cortical nephrons, loop of Henle is short and does not extend into medulla.
III. Vasa recta is absent or highly reduced in cortical nephrons.
Which of the above statements are true?
1. I and II only         2. I and III only
3. II and III only       4. I, II, and III

In the given diagram what would be the value of osmolality of fluid at points A and B respectively?

1. 1000 and 1000

2. 1200 and 1000

3. 1000 and 1200

4. 1200 and 1200

The component of blood which prevents its coagulation in the blood vessels is
1. haemoglobin
2. plasma
3. thrombin
4. heparin.

In a glomerulus
1. Afferent arteriole is thicker than efferent arteriole
2. Afferent capillaries are thicker than efferent capillaries
3. Afferent capillaries are thinner than efferent capillaries
4. Afferent arteriole are thinner than efferent arteriole

Assertion: Unlike bony fishes, marine sharks are not hypoosmotic to seawater.
Reason: Like bony fishes, marine sharks have an internal salt concentration much lower than that of seawater.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false

Assertion: Euryhaline Salmon fish osmoregulate in fresh water like other freshwater fishes.
Reason: In fresh water, salmon increases cortisol secretion which increases the number and size of salt-secreting chloride cells.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: The kidneys of camel are very efficient at reabsorbing water.
Reason: Camels' kidneys have a 1:4 cortex to medulla ratio.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R): 

In the light of the above statements choose the correct answer from the options given below