Question

what was biochemist albrecht kossels contribution to the discovery of the structure of dna?

a. he determined that dna is made of two complementary strands.
b. he identified the five nitrogenous bases in dna and rna.
c. he used radioactive labeling to track dna in viruses.
d. he developed a microscope powerful enough to view dna.

Explanation:

Identify the historical contribution of Albrecht Kossel

Using the History of DNA Discovery knowledge point, we recall that Albrecht Kossel isolated and described the five primary nitrogenous bases: adenine, cytosine, guanine, thymine, and uracil.

Evaluate the given multiple-choice options

• Option A refers to Watson and Crick's double helix model.
• Option B correctly identifies Kossel's discovery of the five nitrogenous bases.
• Option C refers to the Hershey-Chase experiment.
• Option D is historically inaccurate regarding DNA's structural discovery.

Answer:

• (A) He determined that DNA is made of two complementary strands.
• (B) He identified the five nitrogenous bases in DNA and RNA. (Correct answer)
• (C) He used radioactive labeling to track DNA in viruses.
• (D) He developed a microscope powerful enough to view DNA.