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Revision Notes
Genetics and Heredity — Revision Notes
Telangana Open School (TOSS) · Class 12 · Biology
Genetics and Heredity revision notes for Telangana Open School (TOSS) Class 12 Biology: 4 topics in quick points.
50 questions30 flashcards5 concepts
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Key Topics to Revise
1
Heredity and Variation
- Heredity is the transmission of traits from parents to offspring through genes.
- Variation refers to differences among individuals of the same species, even within the same family.
- Variations arise due to mutations, segregation of chromosomes, and recombination of genes during meiosis.
2
Mendel's Experiments and Laws of Inheritance
- Mendel used garden pea (Pisum sativum) for his experiments due to its clear contrasting traits and ease of cross-pollination.
- He studied seven pairs of contrasting traits such as tall vs dwarf, round vs wrinkled seeds.
- Monohybrid cross involves one pair of contrasting traits; dihybrid cross involves two pairs.
3
Mendel's Laws of Inheritance
- Law of Dominance: In a heterozygous condition, only the dominant allele expresses itself.
- Law of Segregation: During gamete formation, alleles separate so each gamete gets one allele.
- Law of Independent Assortment: Genes for different traits assort independently during gamete formation.
4
Deviations from Mendel's Laws
- Incomplete dominance: Neither allele is completely dominant; hybrid shows intermediate trait (e.g., pink flowers in Mirabilis).
- Codominance: Both alleles express fully in heterozygote (e.g., AB blood group, roan coat in cattle).
- Multiple alleles: A gene has more than two forms (e.g., IA, IB, i for blood groups).
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Full NotesKey Concepts
Heredity is the transmission of traitsMendel proposed three lawsIncomplete dominance occurs when the heterozygousSome traits are controlled by moreThis theory states that genes
Frequently Asked Questions
What are the important topics in Genetics and Heredity for Telangana Open School (TOSS) Class 12 Biology?
Key topics in Genetics and Heredity include Heredity and Variation, Mendel's Experiments and Laws of Inheritance, Mendel's Laws of Inheritance, Deviations from Mendel's Laws. Study these first, then practise questions on each for the Telangana Open School (TOSS) Class 12 board exam.
How should I revise Genetics and Heredity for the Telangana Open School (TOSS) Class 12 board exam?
Learn the core ideas first, then work through the 50 practice questions on Genetics and Heredity. Revise definitions regularly and use flashcards for quick recall before the exam.
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