The Sumatran elephant is a critically endangered species.You are part of a research group that is going to sequence its genome in the hope that you can learn more about the species before it disappears.After analyzing its genome, you find a sizable percentage of the DNA is noncoding and not eukaryotic in origin.What is the most likely explanation?
A) The elephant genome is vastly different from other eukaryotic species, a possible reason it has become endangered.
B) The sequences of these elephants are remnants of ancestral retroviral infections.
C) The individual elephant sequenced had recently consumed a large quantity of vegetation, causing plant sequences to be detected in the genome data.
D) The sequences of these elephants are a product of lateral gene transfer.
E) There was contamination in your sequencing samples.

Question

Quizplus · Accepted Answer

The presence of noncoding and non-eukaryotic sequences in the genome suggests that they are remnants of ancestral retroviral infections. This is a common occurrence in many species and has been found in other elephant species as well. It is unlikely that the presence of these sequences is a result of contamination, as they would not be present in every individual of the species. It is also unlikely that the elephant genome is vastly different from other eukaryotic species, as all eukaryotes share a common ancestor and have a similar basic genetic structure. The consumption of vegetation is also unlikely to explain the presence of non-eukaryotic sequences in the genome. The most likely explanation is therefore that these sequences are remnants of retroviral infections.

The Sumatran Elephant Is a Critically Endangered Species