Question

What are the components of genes?

1) Coding DNA (exons) and noncoding DNA
2) Functional RNA (i.e. tRNA), centromeres, telomeres, and introns
3) Only coding DNA (exons)
4) Only noncoding DNA

Answer 1

Genes are composed of exons and introns. Exons code for proteins, while introns are involved in gene regulation. Genes also contain noncoding DNA and functional RNA molecules. Hence, option 1) is correct.

Step-by-step explanation:

Components of Genes

Eukaryotic genes are composed of exons and introns. Exons are the coding sequences that correspond to protein-coding sequences, while introns are the intervening sequences that are involved in gene regulation but are removed from the pre-mRNA during processing. In addition to genes, a genome also contains noncoding DNA that does not encode proteins or stable RNA products.

Splicing and RNA Types

Introns are transcribed into mRNA, but the noncoding mRNA is edited out before translation of the coding portion of a gene. Other components of genes include functional RNA molecules such as tRNA and rRNA, as well as regions called centromeres, telomeres, and regulatory sequences.