DNA replication is studied in a newly discovered bacterium. It takes 30 min for the bacterium to complete a round of replication at 37oC. A Meselson-Stahl-type experiment was performed. The bacteria were grown for several generations in 14N-medium and then switched to 15N-medium. The DNA molecules were then analyzed.

If the mechanism of DNA replication in this bacterium were dispersive, what results would be found when the double-stranded DNA was analyzed in a CsCl gradient after two generations in 15N-medium?

TLS Online TPP Program

#Question id: 5093

#Unit 5. Developmental Biology

Which of the following is a result of gastrulation in animals?

I) The archenteron is formed.

II) The body axes are established.

III) The germ layers are formed.

TLS Online TPP Program

#Question id: 12214

#Unit 7. System Physiology – Animal

A 53-year-old man with a recurrent history of ulcer disease associated with diarrhea and a strong family history of duodenal ulcer disease is suspected of having Zollinger-Ellison syndrome (gastrinoma). Secretin (2 units/kg) was given as a rapid intravenous injection to test for gastrinoma. Which of the following results would support the existence of gastrinoma following secretin administration?

TLS Online TPP Program

#Question id: 29100

#Unit 8. Inheritance Biology

The adult flies that emerged had a eyeless mutation phenotype in Drosophila produces greatly reduced eyes.. When this eyeless fly was crossed to a known reduced eye  mutant fly, all the progeny had normal phenotype. The observed phenotype can be best explained as an example of__

TLS Online TPP Program

#Question id: 9616

#Unit 9. Diversity of Life Forms

Which mutation should least require realignment of homologous regions of a gene that is common to several related species?

TLS Online TPP Program

#Question id: 28616

#Unit 2. Cellular Organization

Which of the following SCF complexes containing components directly binds with the E2 ubiquitin-conjugating enzymes?