Question

in the 1940s, geneticist barbara mcclintock discovered mobile segments of dna. these segments are now commonly known as “controlling elements,” but they are capable of altering gene expression as they change position within a cells genome. in 1950, geneticist esther lederberg discovered a process (the lysogenic cycle) by which bacteria - infecting viruses (phages) pass their genetic material to a bacterial host cell and incorporate itself into the host cells genome. when the host cell divides, the phage dna replicates along with the hosts dna. the student wants to compare mcclintocks discovery with lederbergs. which choice most effectively uses relevant information from the notes to accomplish this goal? a) like mcclintocks discovery, which revealed moving dna segments within a cells genome, lederbergs discovery also involved dna mobility, showing how phage dna will enter a bacterial host cell and incorporate itself into the cells genome. b) both mcclintock and lederberg were geneticists: mcclintock found that phage dna could be passed to bacterial host cells, and lederberg identified dna segments that can change position within genomes. c) mcclintocks and lederbergs discoveries provided insight into how phage dna uses the lysogenic cycle to change position within the genome of a bacterial host cell. d) when mcclintock first discovered dna segments capable of altering gene expression, lederbergs discovery provided geneticists with a better understanding of how tes move

Explanation:

1. First, understand the key - points of each discovery:

• McClintock discovered mobile segments of DNA (TEs) that can change gene expression by altering their position within the genome.
• Lederberg discovered how phage DNA enters a bacterial host cell and replicates along with the host's DNA during the lysogenic cycle.

1. Then, analyze each option:

• Option A: Lederberg's discovery about phage DNA moving within a cell's genome shows DNA mobility similar to McClintock's TEs.
• Option B: Only mentions phage DNA passing to bacteria, not related to DNA mobility like TEs.
• Option C: Focuses on how phage DNA uses the lysogenic cycle to change position, not directly comparable to TEs.
• Option D: Mentions McClintock's discovery in relation to Lederberg's understanding of TEs movement, but it's about Lederberg using McClintock's work, not a direct comparison of the discoveries.

Answer:

A. Like McClintock's discovery, which revealed moving DNA segments within a cell's genome, Lederberg's discovery also involved DNA mobility, showing how phage DNA will enter a bacterial host cell and incorporate itself into the cell's genome.