George is studying a computer model of a dna molecule, in which the letters a, c, g, and t are listed in a very long sequence. the model includes a total of 2000 genes that are scattered along the full length of the molecule. the genes make up only a small fraction of the molecule. george wants to identify the locations of the genes. which would be the most useful first step to follow? a. divide the model molecule into 2000 segments of equal size. b. identify all of the start codons in the model molecule. c. identify the promoter regions in the model molecule. d. divide the model molecule into three-letter pieces.

C.Identify the promoter regions in the model molecule.

Explanation:

Promoters are the sequences present close to the upstream of start site. Promoter is the sequence that serves as binding site for RNA polymerase to start the process of transcription. Since promoter sequences are consensus sequences and all genes have promoters associated with them; identification of promoter sequences can give location of the gene on the otherwise large DNA molecule.

answer: the blood-brain barrier is a layer of specialized membranes and cell processes designed to keep undesirable substances from passing from the bloodstream into the precious tissues of the brain. while the blood-brain barrier does keep most bad things out of the central nervous system, it is not impermeable.

explanation:

the wires in the toaster turning red and the toast crisping and turning brown