Give biological reasons for the following:

The renal cortex has a dotted appearance.

 The diagram given below shows the male urinogenital system of a human being. Study the diagram and answer the questions that follow:

i. Label the parts numbered 1 to 8.

ii. Name the corresponding structure of part (4) in female reproductive system.

iii. What is the role of part 7? [5]

Explain the following terms:

Selective reabsorption.

Name the following :

The structural and functional unit of the kidney.

Study the diagram given below and answer the following questions:  



(i) Name the region in the kidney where this structure is present
(ii) Name the parts labelled 1, 2, 3 and 4.
(iii) Name the stages involved in the formation of urine.
(iv)What is the technical term given to the process occurring in 2 and 3? Briefly describe the process. 

Give reasons for the following:

(ii) Urine is slightly thicker in summer than in winter.

Given below are six sets with four terms each. In each set one term is odd and cannot be grouped in the same category to which the other three belong. Identify the odd one in each set and name the category to which the remaining three belong. The first one has been done as an example.

Example: Calyx, Corolla, Stamens, Midrib

Odd term: midrib

Category: Parts of a flower

(ii) Urethra, Uterus, Urinary bladder, Ureter

The given diagram represents a nephron and its blood supply. Study the diagram and answer the following questions: 
 

i. Label parts 1, 2, 3 and 4.

ii. State the reason for the high hydrostatic pressure in the glomerulus.

iii Name the blood vessel which contains the least amount of urea in this diagram.

iv. Name the two main stages of urine formation.

v. Name the part of the nephron which lies in the renal medulla. 

Name the following:

Organ where urea is produced.

The diagram given below shows the excretory system in humans. Study the same and answer the questions.

(i) Name the parts labelled 1, 2, 3 and 4.

(ii) Give the main function of the parts labelled 5, 6, 7 and 8.

(iii) Name the endocrine gland which could be added in the diagram and state its location/position.