Meselson and Stahl studied DNA in bacteria. They first grew the bacteria in a medium containing only heavy nitrogen, $^{15}\text{N}$, until every DNA molecule in the bacterial cells was heavy. The bacteria were then transferred from the heavy nitrogen medium to a medium containing only light nitrogen, $^{14}\text{N}$. A sample of bacteria from the second generation was taken and the DNA was analysed. Hybrid DNA includes both heavy and light DNA. Which row gives the percentage of heavy DNA strands and the percentage of hybrid DNA molecules in the second generation produced in the medium containing light nitrogen?
- Aheavy DNA strands: 25%; hybrid DNA molecules: 25%
- Bheavy DNA strands: 25%; hybrid DNA molecules: 50%
- Cheavy DNA strands: 50%; hybrid DNA molecules: 25%
- Dheavy DNA strands: 50%; hybrid DNA molecules: 50%