What state is the repressor protein in when tryptophan is absent?

What is the number of phosphates in an atp molecule

Choose the best definition of allele. a. one of several possible versions of a gene, which each produce a different phenotype b. an organism that's purebred for a given trait c. the process of fertilizing a plant with pollen from another plant d. a set of genes that are located on the same chromosome and so are tightly linked

What is a food chain? a.different animals located in different communities b. energy transferred from the sun to plants and then to a series of living things c. rows of crops, such as lettuce, in a field d.animals using one another as food for energy and growth