To study the mechanism of DNA replication, Meselson and Stahl labeled both strands of a DNA molecule with nitrogen-15 and then tracked the location of this label after one round of replication. Which composition describes the products they found?

Ascientist observes certain changes in the physical features of a particular species over time. she concludes that the species has undergone evolutionary change. she wants to study the animals by analyzing their population. she’ll use . the population of this species is decreasing considerably. if this trend doesn’t change, this species will fall under the category of animals. this is a plato question, i need to make up his biology credit.