Curriculum
Science — Third Preparatory
Science — Third Preparatory
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Science — Third Preparatory 2026/2027
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Unit 1 — Chemical Reactions and Their Environmental Impacts
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Unit 2 — Electricity and Magnetism
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Unit 3 — Variation of Traits in Living Organisms
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- 1.1 Why are family members alike but not identical?
- 1.2 How are traits passed on?
- 1.3 Alleles, dominance and recessiveness
- 1.4 Mendel and the discovery of the laws of heredity
- 1.5 Mendel's first law (law of segregation)
- 1.6 The Punnett square
- 1.7 Mendel's second law (law of independent assortment)
- 1.8 Genetic diversity
- 1.9 Genetic (inherited) diseases
- 1.10 Marriage between close relatives
- 1.11 Summary of Lesson 1
- 2.1 Populations
- 2.2 Population growth
- 2.3 Factors affecting population growth
- 2.4 Natural selection
- 2.5 Artificial selection
- 2.6 Natural versus artificial selection
- 2.7 Techniques used in artificial selection
- 2.8 Summary of Lesson 2
- Extra Study Section: Common Mistakes and More Practice
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Unit 4 — Dating Planet Earth
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Unit 1 - Force, Motion, Acceleration and Physical Quantities
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Unit 3 — Variation of Traits in Living Organisms
Unit 3 — Variation of Traits in Living Organisms
1.11 Summary of Lesson 1
1.11 Summary of Lesson 1
- DNA → chromosome → gene; gametes carry one copy, zygote two.
- Alleles, dominant/recessive, homozygous/heterozygous, genotype/phenotype.
- Mendel’s first law segregation; 100% dominant in F₁ and 3 : 1 in F₂.
- Mendel’s second law independent assortment; 9 : 3 : 3 : 1 in F₂.
- The Punnett square predicts offspring.
- Recessive genetic diseases appear when both alleles are the disease allele; carriers look healthy; relatives’ marriage raises risk; screening and counselling reduce it.
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