Question

The technique used by Taylor to explore the nature of DNA replication in Vicia faba is __________________.

• A. autoradiography
• B. chromatography
• C. density gradient centrifugation
• D. autoradiography and chromatography

Answer 1

The correct option is A autoradiography

Herbert Taylor conducted experiments on actively dividing meristematic cells of Vicia faba. He selected root-tip cells and treated them with radioactive thymidine till both the chromatids of all the chromosomes of dividing cells became radioactive.
Further the cells were grown in normal media. In the next generation, one chromatid of each chromosome was labelled while the other was normal. This was detected by the autoradiography technique. This employs the ionization of silver halide, a light sensitive compound on radioactive exposure. The silver atoms formed get deposited on the X-ray film.
Chromatography is a technique used to separate two or more substances in a mixture which have different degrees of solubilities in a given solvent.
Density gradient centrifugation is a technique that helps in the separation of substances based on density. This technique was used by Meselson and Stahl to explore the mechanism of DNA replication.