Practice Exam-Genomic Basics

Genomic Basics
Pdf Summary
The provided document contains questions related to basic genomics concepts. The first question (ID 25231) compares DNA and RNA and asks which statement is true about their structures. The options involve details about nucleotide attachments and base composition. The key point from the commentary is that both DNA and RNA have nucleosides attached to the 1' carbon and phosphate groups attached to the 5' carbon of their sugars. Ribose (RNA sugar) and deoxyribose (DNA sugar) differ at the 2' carbon by a hydroxyl group presence in ribose. RNA and DNA differ in pyrimidines with RNA having uracil while DNA has thymine. The correct answer from the options provided is likely to be: a base is attached to the 1' carbon in both DNA and RNA.<br /><br />The second question (ID 25230) deals with the universal genetic code in humans and asks for the exception among the given statements. The commentary explains that the genetic code consists of codons, sequences of three bases that signal tRNA for amino acid addition, specifying 20 amino acids with three stop codons. Although the genetic code is largely consistent between nuclear and mitochondrial DNA, it is noted there is variation in the third codon position for amino acids except for Methionine and Tryptophan. The incorrect statement among the options is that the genetic code is different for nuclear and mitochondrial DNA, as the commentary suggests overall similarity between the two. Thus, option B, that the genetic code is different for nuclear and mitochondrial DNA, is likely the correct choice for the exception.
Keywords
genomics
DNA
RNA
nucleosides
phosphate groups
ribose
deoxyribose
genetic code
codons
mitochondrial DNA