Explain why you need a prescription for some medicines and others you do not?

During the first month of development, how many layers of cells make up the embryo? a. 1 b. 2 c. 3 d. 4

In many ways, the regulation of the genes of a particular group of viruses will be similar to the regulation of the host genes. therefore, which of the following would you expect of the genes of a bacteriophage? a) regulation via acetylation of histonesb) positive control mechanisms rather than negativec) control of more than one gene in an operond) reliance on transcription activators

Which of the following viruses would most likely have reverse transcriptase? a) an rna-based lytic virusb) an rna-based lysogenic virusc) a dna-based lytic virusd) a dna-based lysogenic virus