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Chapter 8 of 12
Revision Notes

Genetic Disorder

CBSE · Class 11 · Biotechnology

Quick revision notes for Genetic Disorder — CBSE Class 11 Biotechnology. Key concepts, formulas, and definitions for last-minute revision.

74 questions80 flashcards5 concepts

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Key Topics to Revise

1

Chromosomal Abnormalities and Syndromes

  • Chromosomal abnormalities are of two main types: structural chromosomal abnormalities and numerical chromosomal abnormalities.
  • Structural abnormalities change the structure of chromosomes.
  • Numerical abnormalities change the number of chromosomes.
2

Structural Chromosomal Abnormalities

  • Deletion occurs when a segment of a chromosome breaks away, shortening the chromosome.
  • Duplication occurs when a chromosome segment is repeated, making the chromosome longer.
  • Inversion occurs when a chromosome segment breaks, reverses, and reattaches in the same chromosome.
3

Down's Syndrome

  • Down's Syndrome occurs in approximately 1 per 800 live births.
  • It is caused by trisomy of chromosome 21 due to non-disjunction.
  • The karyotype is 47, XX, +21 in females and 47, XY, +21 in males.
4

Klinefelter's Syndrome

  • Klinefelter's syndrome occurs in approximately 1 out of 1000 newborn males.
  • It affects males and has genotype 47, XXY.
  • It results from fertilisation of an XX ova with a Y sperm.

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Full Notes

Key Concepts

Chromosomal disorders are of two mainMonosomy and trisomy are both formsDown syndrome is caused by trisomyKlinefelter syndrome affects males and hasTurner syndrome affects females and has

Frequently Asked Questions

What are the important topics in Genetic Disorder for CBSE Class 11 Biotechnology?
Genetic Disorder covers several key topics that are frequently asked in CBSE 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 Genetic Disorder — CBSE Class 11 Biotechnology?
Understand the core concepts first, then work through the 74 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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