Question: Answer the following question given this paragraph:   Changes to the nucleus of an atom require tremendous amounts of energy, so protons are not easily gained or lost by atoms. Electrons, on the other hand, are held fairly loosely and can often be removed quite easily. When an object loses some electrons, the remaining object is now positively charged because it has an excess of protons. The electrons may either remain free or may attach to another object. In that case, the extra electrons cause that object to become negatively charged. Atoms that have lost electrons and become positively charged are called positive ions, and atoms that have gained electrons and become negatively charged are called negative ions .   Q: Atoms that have gained electrons and become negatively charged are called what?   A:
Answer: negative ions

Question: Answer the following question given this paragraph:   Chemical sedimentary rocks form when crystals precipitate out from a liquid. The mineral halite, also called rock salt, forms this way. You can make halite! Leave a shallow dish of salt water out in the Sun. As the water evaporates, salt crystals form in the dish. There are other chemical sedimentary rocks, like gypsum.   Q: What forms when crystals precipitate out from a liquid?   A:
Answer: chemical sedimentary rocks

Question: Answer the following question given this paragraph:   Structure of the trp operon. The trp operon is composed of 5 structural genes, 1 regulatory gene and other regulatory sequences, including the promoter, operator and leader sequence. Within the leader sequence is the attenuator region. In the presence of tryptophan, the structural genes are not transcribed.   Q: What happens to structural genes in the presence of tryptophan?   A:
Answer:
they are not transcribed