Sometimes PCR fails and instead of having two bands you end up with just one. The elephants represented in lanes 3 and 5 could have been a match to the ivory sample if you failed to amplify one allele in either the ivory or the sample, so you cannot exclude these choices without running the experiment multiple times. On the other hand, you can definitely eliminate the elephants in lanes 1, 2, 4, and 6. Explain why.

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.

organ system-an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.

the endomembrane system i think

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.