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Chapter 16 of 19
Revision Notes

Excretory Products and Their Elimination

ICSE · Class 11 · Biology

Quick revision notes for Excretory Products and Their Elimination — ICSE Class 11 Biology. Key concepts, formulas, and definitions for last-minute revision.

56 questions58 flashcards5 concepts

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An infographic comparing ammonia, urea, and uric acid based on their relative toxicity and the amount of water required for their excretion.
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Key Topics to Revise

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1. Nitrogenous Waste and Modes of Excretion

  • Major nitrogenous excretory products are ammonia, urea, uric acid, creatine, creatinine, trimethylamine oxide, and guanine.
  • Ammonia is highly toxic, highly soluble, and needs much water for elimination.
  • Urea is less toxic than ammonia but still needs to be diluted for elimination from the body.
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2. Human Excretory System: Kidney, Ureter, Bladder, Urethra

  • The human excretory system consists of two kidneys, two ureters, a urinary bladder, and a urethra.
  • The two kidneys each weigh about 150 g in an adult human.
  • Each kidney measures about 10-12 cm long, 5-7 cm broad, and 2-3 cm thick.
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3. Nephron and Renal Corpuscle

  • There are about 1.2 million nephrons in a human kidney.
  • The nephron is the functional and excretory unit of the kidney.
  • A nephron has two main parts: the renal corpuscle and the renal tubule.
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4. Urine Formation: Filtration, Reabsorption, Secretion

  • Urine formation occurs in three steps: glomerular filtration, tubular reabsorption, and tubular secretion.
  • Glomerular filtration is the filtration of blood in the glomerulus to form a protein-free filtrate.
  • About 1100-1200 ml of blood is filtered by the kidneys per minute.

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Full Notes

Key Concepts

Excretion is the removal of wasteAmmonotelism uses ammoniaThe human urinary system includes twoEach kidney is dark redA nephron is the functional unit

Frequently Asked Questions

What are the important topics in Excretory Products and Their Elimination for ICSE Class 11 Biology?
Excretory Products and Their Elimination covers several key topics that are frequently asked in ICSE Class 11 board exams. Focus on the core concepts listed on this page and practise related questions to build confidence.
How to score full marks in Excretory Products and Their Elimination — ICSE Class 11 Biology?
Understand the core concepts first, then work through the 56 practice questions available for this chapter. Revise formulas and definitions regularly, and use flashcards for quick recall before the exam.

Sources & Official References

Content is aligned to the official syllabus. Refer to the board website for the latest curriculum.

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