Answer
You can create your own chapter as long as it is not copying another official or unofficial chapters. Therefore you can use your chapter when playing the game
No, the Dark Angels are a chapter on their own, and the are regular Space Marines, servants of the Emperor who haven't fallen to Chaos. Their name is misleading however.
Any, there's nothing that says you have to paint them a certain colour scheme. You get to choose to paint them by a certain chapter's colour scheme (ex. Blood Ravens) or you can make your own and just paint them how ever you want!
Making your own chapter is quite easy. However, making one from the pre-heresy era is not recommended as all the chapters then were known and numbered. Don't use the weapons from other races in your chapter, but you can make some good models from parts or equipment from them, just stay away from their weapons. Don't make the weapons to are different to traditional Marine weapons.
With a bit of research, the answer is yes. Along with many, many others.
A winning tactic is a good tactic, every player got his own.
Jack made his announced his own tribe in Chapter 8: Gift for the Darkness. He said "I'm going off by myself. He can catch his own pigs. Anyone who wants to hunt when I do can com too." In the end of he chapter Jack tries to show his power and steal Piggys specs.
Maybe, since Marine Biologists have to make fundraisers to pay for their research. The buisness could be what they use for fundraisers.
Of course
Yes. for Languages, it does. however, i think they make their own tests for math and sciences.
Peggy and Maddie feel like intruders in their own classroom at the beginning of the chapter because a new student, Wanda, is sitting in Maddie's seat and their classmates seem to be paying more attention to Wanda than to them. This makes them feel left out and unwelcome in their own space.
organism that can make its own food by photosynthesis or chemosynthesis.
Marine organisms that make their own food primarily include phytoplankton, which are microscopic plants that use photosynthesis to convert sunlight, carbon dioxide, and nutrients into energy. Other examples include macroalgae, such as seaweeds, and some species of cyanobacteria. These organisms form the foundational base of marine food webs, supporting a wide range of marine life. Through photosynthesis, they contribute significantly to oxygen production and carbon fixation in ocean ecosystems.