Most free PDFs of this textbook are scans (300-600 DPI). True "extra quality" (searchable text, clean graphics) usually requires the official digital edition (paid, often ~5,000-10,000 FCFA).
If you find a scanned PDF, look for:
1. Le Matériel Génétique
2. La Méiose et le Brassage Génétique Division réductionnelle qui passe de $2n$ à $n$. bord bleu svt terminale d pdf extra quality
Some teachers legally share scanned chapters (under educational exceptions in copyright law — exception pédagogique in France). Ask your instructor for a password-protected download of essential sections. Most free PDFs of this textbook are scans (300-600 DPI)