During meselson and stahl’s experiment, e. coli was grown on heavy nitrogen for what purpose?
a. so each generation of dna would have a different weight to distinguish them by.
b. so each generation of protein would have a different weight to distinguish them by.
c. to determine how the bacteria functioned with a heavier element.
d. to see how the heavy nitrogen affected their dna.

The allele for curly hair is incompletely dominant. if a mother is homozygous for curly hair and the father is homozygous for straight hair, what percentage of the offspring will exhibit characteristics of both parents? 25 percent 50 percent 75 percent 100 percent

Zoo geographic regions are characterized by the presence of specific groups of animals these regions are determined by the taxonomic or phylogenetic relationships of animals. the map shows the zoogeographic regions proposed by the naturalist alfred russel wallace in 1876. the similarities of organisms in which two areas numbered above provide the best evidence for common ancestry between the organisms in both locations ?

Climate warming trends allow plant and insect species to inhabit larger ranges. select the best answer from the choices provided