The "cambrian explosion" refers to a. the creation of earth. b. the development of the first true cell. c. the origination of life. d. the origination of all major phyla of animals. e. the mass extinction of dinosaurs.

The trp operon in e.coli regulates genes that code for enzymes required for synthesis of the repressible operon. when tryptophan is not available amino acid tryptophan. the trp operon is a in the environment, the trp repressor protein activeinactiveregulated. therefore, rna polymerase can bind to the genes to begin transcription.

Wich organism obtains its energy from dead or decaying matter

Which of the following types of stars are dim but can have high surface temperatures? giants main sequence stars supergiants dwarfs