Which statement about repetitive DNA is true?

Which statement about repetitive DNA is true?

• A. It codes for most proteins
• B. It is highly conserved
• C. It is only found in bacteria
• D. It consists of many repeated noncoding sequences

Answer: (D)

Repetitive DNA is made up of sequences that occur in many copies within the genome and are typically noncoding, rather than forming the protein-coding instructions. The statement that best fits this idea is that repetitive DNA consists of many repeated noncoding sequences. These repeats show up in large blocks, such as satellite DNA at centromeres and telomeres, as well as various microsatellite and transposable element repeats. They’re not primarily used to make proteins, and they tend to evolve more rapidly and be less conserved than coding genes. The other ideas don’t fit as well because most of the genome is not devoted to protein-coding genes, so repetitive regions aren’t the main source of proteins. Repetitive DNA is not uniquely found in bacteria; it’s present in many organisms, especially eukaryotes, though its abundance varies. And while some sequences can be conserved in particular families, repetitive DNA as a whole is not highly conserved across species.

Repetitive DNA is made up of sequences that occur in many copies within the genome and are typically noncoding, rather than forming the protein-coding instructions. The statement that best fits this idea is that repetitive DNA consists of many repeated noncoding sequences. These repeats show up in large blocks, such as satellite DNA at centromeres and telomeres, as well as various microsatellite and transposable element repeats. They’re not primarily used to make proteins, and they tend to evolve more rapidly and be less conserved than coding genes.

The other ideas don’t fit as well because most of the genome is not devoted to protein-coding genes, so repetitive regions aren’t the main source of proteins. Repetitive DNA is not uniquely found in bacteria; it’s present in many organisms, especially eukaryotes, though its abundance varies. And while some sequences can be conserved in particular families, repetitive DNA as a whole is not highly conserved across species.