Excretion — Homi Bhabha Class 9 Biology MCQs with Solutions
Free Homi Bhabha Class 9 Biology Excretion MCQs with step-by-step solutions (12 questions). Part of Life Processes. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Excretion · medium · theory
The process of removing harmful metabolic wastes from the body is called:
A. digestion
B. circulation
C. respiration
D. excretion ✓ Correct
Solution: Excretion removes toxic waste products of metabolism from the body.
Q2 — Excretion · medium · theory
The main excretory organs in human beings are the:
A. lungs
B. kidneys ✓ Correct
C. intestines
D. liver
Solution: The kidneys filter the blood and remove waste as urine.
Q3 — Excretion · hard · theory
The functional (structural) unit of the kidney is the:
A. neuron
B. nephron ✓ Correct
C. alveolus
D. nephridium
Solution: Each kidney contains about a million nephrons that filter the blood and form urine.
Q4 — Excretion · medium · theory
The main nitrogenous waste excreted in human urine is:
A. glucose
B. starch
C. urea ✓ Correct
D. proteins
Solution: Urea, formed in the liver from excess amino acids, is the chief nitrogenous waste in urine.
Q5 — Excretion · hard · theory
Which organ, besides the kidneys, helps in excretion by removing carbon dioxide?
A. pancreas
B. lungs ✓ Correct
C. heart
D. stomach
Solution: The lungs excrete carbon dioxide (and some water vapour) during breathing.
Q6 — Excretion · medium · theory
The tube that carries urine from the kidney to the urinary bladder is the:
A. urethra
B. nephron
C. artery
D. ureter ✓ Correct
Solution: The ureter carries urine from each kidney to the bladder; the urethra removes it from the body.
Q7 — Excretion · hard · theory
Plants get rid of some waste products by:
A. urinating
B. shedding leaves and storing wastes in cells ✓ Correct
C. sweating like animals
D. using kidneys
Solution: Plants excrete wastes by shedding leaves/bark, releasing gases through stomata, and storing wastes in cells or resins.
Q8 — Excretion · easy · theory
The basic filtration unit of the human kidney is the:
A. Neuron
B. Alveolus
C. Villus
D. Nephron ✓ Correct
Solution: Each kidney contains about a million nephrons. A nephron filters the blood and forms urine. Neurons are nerve cells, alveoli are in the lungs and villi are in the small intestine.
Q9 — Excretion · easy · theory
The main nitrogenous waste removed from the human body in urine is:
A. Glucose
B. Amino acids
C. Proteins
D. Urea ✓ Correct
Solution: The liver converts excess amino acids into urea, which is carried by blood to the kidneys and removed in urine. Glucose and amino acids are useful and are normally reabsorbed.
Q10 — Excretion · medium · theory
While urine is being formed, useful substances such as glucose and a large part of the water are reabsorbed back into the blood. This happens because:
A. The body must conserve useful materials while removing only the wastes ✓ Correct
B. Glucose is a waste product
C. Water is toxic to the body
D. The kidney is unable to filter glucose
Solution: The kidney first filters out many substances, then selectively reabsorbs the useful ones (glucose, salts, most water). This conserves valuable materials and prevents dehydration while still excreting wastes.
Q11 — Excretion · hard · theory
The kidneys of a patient have stopped working. The artificial process used to remove nitrogenous wastes from the blood is called:
A. Transamination
B. Transpiration
C. Dialysis ✓ Correct
D. Osmosis
Solution: Dialysis uses an artificial kidney machine to filter wastes such as urea from the blood when the kidneys fail. Transpiration and osmosis are natural processes, and transamination relates to amino acids.
Q12 — Excretion · hard · theory
Unlike animals, plants have no special excretory organs. They can still get rid of many waste products because:
A. Plants convert all their wastes back into food
B. Gaseous wastes diffuse out, some wastes are stored in leaves and bark that fall off, and others are stored harmlessly in cells ✓ Correct
C. Plants possess a pair of kidneys
D. Plants produce no waste products at all
Solution: Plants remove gaseous wastes (oxygen, carbon dioxide) by diffusion through stomata, store some wastes in old leaves and bark that are shed, and lock others in vacuoles or as resins and gums. So they manage without excretory organs.