Nitrogen Fixation: Root and Bacteria Interactions. Nitrogen is an important macronutrient because it is part of nucleic acids and proteins. ... The most important source of BNF is the symbiotic interaction between soil bacteria and legume plants, including many crops important to humans.
Punnet squares are a useful tool for predicting what the offspring will look like when mating plants or animals. Reginald Crundall Punnett, a mathematician, came up with these in 1905, long after Mendel's experiments. Let's take a look at how Punnet squares work using the yellow and green peas example from im not sure about the tree by three thing but maybe this will help :)
Single circular piece of DNA
The initiation of DNA replication occurs in two steps. First, a so-called initiator protein unwinds a short stretch of the DNA double helix. Then, a protein known as helicase attaches to and breaks apart the hydrogen bonds between the bases on the DNA strands, thereby pulling apart the two strands.
So yeah xD
~ Hope this helps! -by Kana ^^
Answer:
I'm pretty sure its C i haven't done this since 7th grade