Complete 26-page workbook for Edexcel IGCSE Biology (4BI1 Higher Tier) and Science Double Award (4SD0), covering all specification points 3.1–3.45 across 22 structured sections. The only Topic 3 resource with dedicated full sections on sex-linked inheritance (haemophilia worked cross), IVF (four stages + ethical considerations), codominance with the ABO blood group Punnett square, and pedigree analysis with “gold rules”. 21 graded exam-style questions with full mark-scheme answers across 6 topic sections. 17-point RAG self-check. 30+ Tutor Notes and Exam Traps. All 4BI1-only extensions clearly badged. Safe to distribute directly to 4SD0 groups without modification.

“The workbook opens with a 17-point RAG self-check tracker in which students mark each statement Red, Amber, or Green before working through the workbook and again after. The 17 statements are organised to mirror the six content families of Topic 3 and include all content areas: asexual versus sexual reproduction; flower labelling and function; cross- versus self-pollination comparison; fertilisation, seed formation and germination; human reproductive system labelling; placenta and amniotic fluid; four menstrual cycle hormones and hormone graph reading; IVF and ethical implications; DNA structure and gene-protein relationship; key genetics vocabulary; mitosis and meiosis comparison including chromosome number and variation; monohybrid Punnett square using the seven-step method; sex-linked inheritance cross and explanation of why more males are affected; codominance cross including the ABO blood group system; causes of variation and continuous versus discontinuous; natural selection with Lamarckian rejection; and pedigree diagram analysis with dominant or recessive determination and genotype assignment. Statement 17 (pedigree analysis) is identified in the Tutor Note as new to this edition and as the highest-priority Red statement to address for 4BI1 candidates. The dual-recheck structure — one column before, one column after — provides a measurable formative assessment record that teachers can review without any marking, and that students can use as an examination-readiness test independent of any teacher involvement.”