The given diagram represents the structure of a human excretory system. Study the diagram and answer any of the four questions from (a) to (e).
(a) Identify the part 1 in excretion.
(i) Kidney
(ii) Ureter
(iii) Urethra
(iv) Nephron
Answer
Part 1 is Ureter. It is a tube that transports urine from the kidney to the urinary bladder .
So, the correct answer is (ii)
(b) Which of these is the structural and functional unit of part 2?
(i) Alveoli
(ii) Nephron
(iii) Neuron
(iv) None of these
Answer
- Part 2 is kidney.
- The structural and functional units of a kidney are nephrons .
- Nephrons are kidney cells that remove excess water and waste from blood and produce urine.
So, the correct option is (ii) Nephron.
(c) What will happen, if one kidney of a person is removed?
Answer
If one kidney of a person is removed, they can lead a healthy and normal life because the same function is provided by the other kidney.
However, the risk of developing mild high blood pressure is slightly higher if we have one kidney instead of two.
(d) The urge to urinate can be controlled. Give a reason.
Answer
The urinary bladder is muscular . It is under the control of the nervous system . Hence, we can control the urge to urinate.
(e) Choose the correct path of urine in our body:
(i) kidney → ureter → urethra → urinary bladder
(ii) kidney → urinary bladder → urethra → ureter
(iii) kidney → ureters → urinary bladder → urethra
(iv) urinary bladder → kidney → ureter → urethra
Answer
- Kidneys: These are the paired organs where urine formation happens.
- Ureters: Small muscular tubes which extend from the kidneys and carry urine to the urinary bladder are called ureters .
- Urinary Bladder: It is a muscular structure which receives urine from ureters and stores it .
- Urethra: It is a small tube that extends from the urinary bladder to an external opening .
So, the urine travels from kidney → ureters → urinary bladder → urethra
Thus, the correct option is (iii)
