Question

(a) Draw a diagram of excretory system in human beings and label on it:
Aorta, vena cava, urinary bladder, urethra.
​(b) List two vital functions of the kidney.

Answer 1

Part (a): Structure of excretory system:

1. Vena cava: The vena cava carries the deoxygenated blood back to the heart.
2. Aorta: The aorta brings the oxygenated blood from the heart towards the two kidneys.
3. Urinary bladder: The urinary bladder is the sac-like structure that stores the urine that is constantly getting excreted from the kidney.
   
4. Urethra: The urethra acts as the tubule that helps with the removal of urine during micturition.
   

Human excretory system

[Note: Aorta and vena cava are components of the circulatory system.]

Part (b): Functions of kidney:

1. Kidney filters the wastes out of the blood and forms urine

2. Kidney helps maintain the water and salt balance in the system by maintaining the level of ions in the system.