Ribosomal and tRNA genes are located in part of the chromosome that is rarely transcribed. Inappropriate movement of DNA from one region of the chromosome to another region of the chromosome can lead to inappropriate gene expression. Eukaryotic RNA polymerase ends transcription at the terminator site. The start codon signals RNA polymerase to start transcription. Translation of an mRNA molecule ends before the ribosome reaches the end of the mRNA molecule.
Fetal hemoglobin has a greater affinity for oxygen than does adult hemoglobin.
Different hemoglobin genes make up the hemoglobin gene family. Pseudogenes fail to encode functional proteins. It shortens the RNA molecule. Pre-mRNAs from the same gene can give rise to different mRNAs in different tissues. It is a highly regulated process.