Question

Which among the following was used as an experimental model by Taylor in his experiments related to DNA and chromosomes?

• A. Vicia faba
• B. Streptococcus pneumoniae
• C. Drosophila melanogaster
• D. E.coli

Answer 1

The correct option is A Vicia faba

J.H.Taylor in 1958 conducted experiments to prove the semi-conservative nature of DNA replication on the 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.
Then the cells were grown in normal media. In the next generation, one chromatid of each chromosome was labelled while the other was normal. This highlighted the fact that DNA replication occurs in a semi-conservative way.

The smooth and rough strains of Streptococcus pneumoniae were used by Griffith in his transformation experiments.
Drosophila melanogaster was used as a model organism in the experiments conducted by Morgan.
E.coli is frequently used for genetic manipulation in several experiments of biotechnology. These were also used by Messelson and Stahl in their experiments to explore the semi-conservative nature of DNA replication.