A human liver cell and a human nerve cell both contain the same complete set of DNA. However, the liver cell produces proteins for metabolism and detoxification, while the nerve cell produces proteins for transmitting signals. What is the benefit of this differential gene expression between these two cell types?

When lactose is present in the environment, it binds to the repressor protein of the lac operon. This binding causes the repressor to change shape and detach from the DNA. What is the result of the repressor detaching from the DNA?

The amino acid leucine is encoded by six different codons (UUA, UUG, CUU, CUC, CUA, CUG). What does this redundancy imply about the relationship between a gene’s nucleotide sequence and its protein product?

A diagnostic lab wants to test for the presence of the COVID-19 virus, which is an RNA virus. The test, called RT-PCR, requires the genetic material to be in the form of DNA. Why is it necessary to use reverse transcription in this diagnostic test?

A scientist uses a restriction enzyme to cut open a bacterial plasmid and a gene of interest. The ends created are known as “sticky ends.” Why are these sticky ends so important for making a recombinant plasmid?

A sterile male release program involves releasing a large number of radiation-sterilized male mosquitos into a wild population. When a sterile male mates with a wild female, what is the expected outcome for the population?

A key enzyme in the HIV life cycle is reverse transcriptase. Many anti-HIV drugs, such as AZT, work by targeting this enzyme. What would be the most immediate effect of a drug that successfully inhibits reverse transcriptase?

The central dogma of molecular biology states that genetic information flows from DNA to RNA to protein. However, certain viruses, such as HIV, can synthesize DNA from an RNA template. What is the name of this process?

A researcher has isolated a new gene from a species of deep-sea bacteria and wants to understand its function. The first step is to determine the exact order of the adenine (A), guanine (G), cytosine (C), and thymine (T) bases. What is the name of this technique?

A polypeptide chain is being synthesized from an mRNA molecule with the sequence 5′AUG−GCA−UAU−3′. Which of the following is the correct sequence of amino acids that would be produced?