Genetic Code and Translation Quiz

<p>EF-TU, peptidyl transferase, and EF-G (B)</p> Signup and view all the answers

<p>Signaling the end of translation and the release of the polypeptide chain. (D)</p> Signup and view all the answers

<p>Lactose is absent during glucose metabolism. (B)</p> Signup and view all the answers

<p>It alters chromatin structure to make DNA more accessible for transcription. (A)</p> Signup and view all the answers

<p>Regulated expression can respond to environmental signals, while constitutive expression is always active. (D)</p> Signup and view all the answers

<p>The location of the mutation relative to the gene it influences. (C)</p> Signup and view all the answers

<p>They facilitate the recruitment of transcription factors and enhance the rate of transcription. (C)</p> Signup and view all the answers

<p>Methylation; negative effect (C)</p> Signup and view all the answers

<p>It creates different mRNA transcripts from the same gene. (A)</p> Signup and view all the answers

<p>A silencing mechanism that can downregulate gene expression. (D)</p> Signup and view all the answers

<p>Missense changes one amino acid, nonsense creates a premature stop codon. (B)</p> Signup and view all the answers

<p>Substitution mutations (C)</p> Signup and view all the answers

<p>To ensure accurate nucleotide pairing during DNA synthesis. (B)</p> Signup and view all the answers

<p>It forms thymine dimers; nucleotide excision repair can fix it. (C)</p> Signup and view all the answers

<p>Forward mutation (B)</p> Signup and view all the answers

<p>Enzymes that cut DNA at specific sequences. (B)</p> Signup and view all the answers

<p>The lack of post-translational modifications in prokaryotes. (A)</p> Signup and view all the answers

Methylation of DNA is a common DNA modification, affecting gene expression by influencing whether transcription occurs.

Alternative splicing creates different mRNA versions from one gene, leading to different protein products, regulating gene expression.

RNAi is a gene silencing process that reduces expression of specific mRNAs.

Point mutations include transitions (purine to purine or pyrimidine to pyrimidine) and transversions (purine to pyrimidine or vice versa).

A silent mutation changes a codon but does not alter the amino acid sequence of the protein.

Spontaneous mutations occur naturally without external causes. Common causes include tautomerization and errors during DNA replication.

DNA polymerase has an ability to check for errors after making a base-pair, fixing errors before next base-pair is created.

UV light causes thymine dimers, which distort DNA.

Molecular cloning involves isolating DNA, inserting it into a vector, and then using a host cell to copy the DNA.

Mammalian genes cannot be directly expressed in prokaryotes due to differences in genetic regulatory mechanisms.

A sequence of three nucleotides that codes for a specific amino acid in protein synthesis.

Transfer RNA carries amino acids to the ribosome during protein synthesis. It has a specific structure with an anticodon that pairs with mRNA.

Enzymes that attach the correct amino acid to its corresponding tRNA.

tRNA's anticodon pairs with mRNA's codon according to established base pairing rules.

Involves the Shine-Dalgarno sequence on mRNA binding to the ribosome.

Involves the ribosome binding to the 5' cap of mRNA, unlike prokaryotes.

Process of adding amino acids to the growing polypeptide chain.

Stop codons signal the end of protein synthesis.

Genes expressed continuously and at a stable rate.

Bind to DNA to enhance transcription of specific genes.