Give reason/explain:

Why does the cortex of kidneys shows a 'dotted' appearance?

Give reason/explain:

We urinate fewer times in summer than in winter and the urine passed is generally thicker.

Given below is a simple diagram of the longitudinal section of a human kidney. Study the same and answer the following questions:

(a) Name the part of kidney which is found between medulla and pelvis.

(b) What is the basic structural and functional unit of kidney ?

(c) What is main function of kidney ?

(d) Mention the exact location of kidney.

(e) Write two differences in the composition of blood flowing through blood vessels A and B.

(f) Name the part of kidney which collects urine for the first time from the nephrons.

(g) Define 'Osmoregulation'.

(h) Name the technique which is normally suggested by the doctors to the patients in case of a permanent damage to both the kidneys.

(i) Name the hormone which is associated with the 'reabsorption' step of urine production.

(j) Draw a neat and labelled diagram of a malpighian capsule.

Given alongside is the figure of certain organs and associated parts in the human body. Study the same and answer the questions that follow:

(a) Name all the organ-systems shown completely or even partially.

(b) Name the parts numbered 1 to 5.

(c) Name the structural and functional unit of the part marked '1'.

(d) Name the two main organic constituents of the fluid that flows down the part labelled '3'.

(e) Name the two major steps involved in the formation of the fluid that passes down the part labelled '3'.