Reviewing Protein Synthesis (Virtual Test)

When the protein is being made, the code is read __________.

• by DNA Polymerase

• by RNA Polymerase

• by the Ribosome

The following RNA strand was produced:

CGA GUG AAU CGU UAA

Which of the following DNA strands could have been the template for this RNA?

• CGA GUG AAU CGU UAA

• GCU CAC UUA GCA AUU

• GCT CAC TTA GCA ATT

• TTA ACG ATT CAC TCG

An environmental factor resulted in a change in just one nucleotide.

In this genetic mutation, Cytosine nucleotide is added instead of an Adenine nucleotide. The gene is transcribed normally.

During translation, the ribosome reaches the section of mRNA with the changed nucleotide- this causes the wrong amino acid to be added. The rest of the amino acids are the same as those that would be found in a normal version of the protein.

Which statement best describes this type of genetic mutation?

• It was a silent mutation

• It was a frameshift mutation

• It was a nonsense mutation

• It was a missense mutation

Which of these is a major difference between DNA Replication and Transcription?

• mRNA molecules produced by Transcription are much shorter in length than the DNA molecules produced by DNA Replication.

• DNA Replication takes place in the nucleus, while Transcription takes place in the cytoplasm.

• DNA replication involves adding RNA nucleotides with the nitrogenous base uracil, while Transcription involves adding DNA nucleotides the nitrogenous base thymine.

What is made during transcription?

• DNA

• mRNA

• Proteins

• RNA Polymerase

Which stage of protein synthesis involves mRNA, a ribosome, tRNA, and amino acids and results in the creation of a polypeptide/protein?

• DNA Replication

• Translation

• Transcription

The process pictured here will create a ____________________.

• new copy of the DNA molecule

• copy of the gene that can leave the nucleus

• protein

Which of the following is a true statement about codons?

• In translation, an mRNA codon determines which tRNA will bring its specific amino acid

• A codon is a sequence of three amino acids.

• A codon is a sequence of four nitrogenous bases.

When an extra nitrogen base is inserted into DNA sequence of a gene, the protein product of the gene is usually nonfunctional. Which of the following statements BEST explains why?

• The inserted base increases the rate of translation in the corresponding mRNA sequence. The protein will be produced too many times. An excess of the protein in the cell will cause it to not work properly.

• The inserted base causes all codons in the mRNA sequence after the location of the mutation to code for incorrect amino acids. The resulting protein has a different structure and therefore will not work.

• The inserted base causes the DNA sequence to be transcribed into the RNA in the opposite direction. The ribosome will read the mRNA code backwards, causing all of the amino acids to be incorrect. The resulting protein has a different structure and therefore will not be able to do its job.

There are 64 codons and 20 amino acids. They are listed in a codon chart (like this one). Which of the following is true?

• Each amino acid is specified by only one codon

• Different codons can specify the same amino acid

• Each codon specifies a different amino acid