Features of thanatophoric dysplasia include macrocephaly, narrow bell-shaped thorax, normal trunk length, and severe shortening of the limbs. Other features of this condition include a narrow chest, short ribs, underdeveloped lungs, and an enlarged head with a large forehead and prominent, wide-spaced eyes. Most affected infants die of respiratory failure shortly after birth.
7.2 .2 Explain the process of DNA replication in prokaryotes, including the role of enzymes (helicase, DNA polymerase, RNA primase and DNA ligase), Okazaki fragments and deoxynucleoside triphosphates. The explanation of Okazaki fragments in relation to the direction of DNA polymerase III action is required.
What is the function of DNA polymerase I? Proofreads DNA. (about 20 at a time before it dissociates). It is a 5' to 3' DNA polymerase but also has 5' to 3' and 3' to 5' exonuclease activity to proof read and correct mismatches. It works with DNA:DNA as well as RNA:DNA. It is responsible to replacing Okazaki RNA fragments with DNA fragments.