Answer:
A. When many species share a single ancestor
Explanation:
To explain the nature of things
Answer:
This experiment proved that DNA replicated semiconservatively; half the original polynucleotide is conserved in each of the two copies
Explanation:
Semi-conservative mode of replication means that the two strands of DNA unwind from each other, and each of themacts as a template for synthesis of a new, complementary strand. As a result, two formed DNA moleculesc ontain one original strand and one new strand.
Meselson and Stahl experiment showed this model by labeling the DNA of bacteria across generations using isotopes of nitrogen ( patterns of DNA labeling showed the mode of replication).
I would say that the fishes exhibited the greatest diversity (though the brachiopods also had considerable diversity) and mostly were of the ostracoderms (with a platey or shell-like skin and no jawbone) which exhibited many varieties and also the placoderm which had gills, a jawbone and fins so was developing characteristics of modern fish.
