This is the primary official platform for digital versions of Russian textbooks. You can often access the interactive electronic form (E-form) through their official website .
While not the full textbook file, RESH provides video lessons and materials that follow the same curriculum used in Zakharov's book. obshchaia biologiia 11 klass uchebnik zakharov onlain
"ГДЗ биология 11 класс Захаров" (for homework solutions). This is the primary official platform for digital