Under which of these conditions would scientists use the polymerase chain reaction (PCR) before they analyze a DNA sample? A The DNA sample comes from a bacterium or virus.

B
The DNA sample has been cut into fragments by restriction enzymes.

C. Only a small amount of the DNA sample is available

D. The DNA sample includes regions that are transcribed into mRNA.

The fish shown above is a tarpon. it is a fast-swimming and powerful open-water fish. its closest relatives, oddly, are burrow-dwelling conger eels that stay on the bottom. both eels and tarpon developed from snake-like larvae that float in the plankton during the first stages of life. once they mature, tarpon and eels are not found near one another in the ocean. the tarpon and the eel illustrate all of the following except