Although the capture and trading of great apes has been banned in 112 countries since 1973, it is estimated that about 1000 chimpanzees are removed annually from Africa and smuggled into Europe, the United States, and Japan. This illegal trade is often disguised by simulating births in captivity. Until recently, genetic identity tests to uncover these illegal activities were not used because of the lack of highly polymorphic markers (markers that vary from one individual to the next) and the difficulties of obtaining chimpanzee blood samples. A study was reported in which DNA samples were extracted from freshly plucked chimpanzee hair roots and used as templates for PCR. The primers used in these studies flank highly polymorphic sites in human DNA that result from variable numbers of tandem nucleotide repeats. Several offspring and their putative parents were tested to determine whether the offspring were 'legitimate' or the product of illegal trading. The data are shown in the following Southern blot.

Examine the data carefully and choose the best conclusion.

a. None of the offspring are legitimate.
b. Offspring B and C are not the products of these parents and were probably purchased on the illegal market. The data are consistent with offspring A being legitimate.
c. Offspring A and B are products of the parents shown, but C is not and was therefore probably purchased on the illegal market.
d. There are not enough data to draw any conclusions. Additional polymorphic sites should be examined.
e. No conclusion can be drawn because 'human' primers were used. <>

Key Concepts

Polymorphic Markers

Polymorphic markers are DNA sequences that vary among individuals in a population, making them useful for genetic analysis. These markers can include single nucleotide polymorphisms (SNPs) or variable number tandem repeats (VNTRs). In the context of the question, highly polymorphic markers are essential for distinguishing between individuals, particularly in identifying the genetic relationships between chimpanzees and their offspring.

PCR (Polymerase Chain Reaction)

PCR is a molecular biology technique used to amplify specific DNA sequences, allowing for the analysis of small amounts of genetic material. In this study, PCR was employed to generate sufficient DNA from chimpanzee hair roots for testing. This technique is crucial for genetic identity testing, especially when samples are limited or difficult to obtain.

Southern Blotting

Southern blotting is a method used to detect specific DNA sequences within a complex mixture. It involves transferring DNA from a gel to a membrane and hybridizing it with labeled probes that bind to the target sequences. In the context of the question, the Southern blot data would provide visual evidence of genetic relationships, helping to determine the legitimacy of the offspring based on their genetic profiles.