The correct answer is option A. Carrying the genetic code and determining an organism's structure and function are the functions of DNA. It is the hereditary material in almost all other organisms. The information in a DNA is stored as codes that is composed of chemical bases.
The research party began by exploring the embryonic development of whales' cousins, the dolphins. These creatures are intriguing because, for a brief time during development, they sprout hind limbs . That's why dolphins lose their 'legs'.” In whales, however, the story is more complex.
So dark linen thread structure is chromosome that we see. And and by molecule heritage that we contain.