DNA (deoxyribonucleic acid)
I believe the answer is A
Answer:
One band of light density and one band of heavy density.
Explanation:
According to conservative model of replication, the original strands do not separate from each other during replication. Hence, after replication the old strands are together and the new strands are together.
Here, cells were grown in 14N medium first so 14N was used for DNA replication and all DNA molecules had 14N. When the cells were transferred to 15N medium, only 15N was available for replication process. New DNA molecules would be synthesised using 15N (15N15N) and old DNA molecules have 14N (14N14N). Hence, in density gradient one band will be of light density (14N14N) and one band will be of heavy density (15N15N).
Often times, non-human life in an urban ecosystem is more disturbed in a way that changes happen rapidly, such as the soil and plant cover and temperature and water availability
