1. The right answer is B. Chromosome
In its most scientifically rigorous definition, a chromosome is a fully condensed structure of chromatin.
In optical microscopy, condensed regions formed of heterochromatin and decondensed regions of euchromatin are distinguished on the chromosomes. The genes expressed are located mainly at the level of euchromatin.
2. The right answer is B.
Genetic engineering is a technique of molecular biology allowing, in a controlled way, the study of gene modification: their isolation, their cloning, their sequencing, their cutting ... for a basic or applied research purpose. In medicine, it is used to produce recombinant proteins (from recombinant DNA) such as insulin.