A radioactive probe is generated using the actin gene from yeast.This probe is used in a Southern blot analysis of EcoRI digested genomic DNA from the ciliated protozoan Tetrahymena thermophila.The autoradiogram shows a single-labeled band of 4 kb in size.This means that the Tetrahymena actin gene is:
A)4 kb in size.
B)the same size as the yeast gene.
C)present in one copy in the genome.
D)present in four copies in the genome.
E)identical in sequence with the yeast gene.

Question

Quizplus · Accepted Answer

The presence of a single-labeled band indicates that there is only one copy of the Tetrahymena actin gene in the genome. The size of the band (4 kb) does not necessarily indicate that the gene itself is 4 kb in size, as there could be additional non-coding regions or introns present. The similarity in size to the yeast gene is also not relevant, as there could be differences in gene structure or non-coding regions between the two species. Similarly, the band size does not provide information on the sequence identity between the yeast and Tetrahymena actin genes.

A Radioactive Probe Is Generated Using the Actin Gene from Yeast.This