When chromatin is in the form of a 30 nm fibril, how many copies of h1 and h2a histone proteins would be found in a stretch of chromatin containing 20 nucleosomes?.

Legumes, a type of plant, require rhizobia, a type of soil bacteria, to survive since these organisms fix nitrogen during photosynthesis. rhizobia use the legumes for food. what would most likely happen to the legume population if rhizobia suddenly became extinct?

Keeping in mind the life cycle of bacteriophages, consider the following problem: during the reproductive cycle of a temperate bacteriophage, the viral dna inserts into the bacterial chromosome where the resultant prophage behaves much like a trojan horse. it can remain quiescent, or it can become lytic and initiate a burst of progeny viruses. several operons maintain the prophage state by interacting with a repressor that keeps the lytic cycle in check. insults (ultraviolet light, for example) to the bacterial cell lead to a partial breakdown of the repressor, which in turn causes the production of enzymes involved in the lytic cycle. as stated in this simple form, would you consider this system of regulation to be operating under positive or negative control?

Be in this im starting a with you so if you want you can get a partner for this. but basically im going to assign you guys a biome and you have to have a big sheet paper and you will turn it into 4 squares. the top right square is will be a drawing square for a drawing you will make of your biome. the top left square is about the biomes plants and drawings of them. the bottom left square is about the biomes animals. the bottem rights square is about the description of the biome. leave a comment or an answer and i will assign biomes. if your request one thats the one you get. send me a link to the project and i will grade ! im not a teacher btw.