6.3 Mastery Check

A sequence of amino acids called a​ (a)   is produced during the process of​ (b)   . During this process, the ​ (c)   of a tRNA molecule binds to a codon of mRNA.

• polypeptide
• translation
• anticodon
• DNA polymerase
• transcription
• intron

Consider this sequence of nucleotides in an mRNA molecule:

AGGGUCCAA

Which could describe the translation of this sequence?

• 3 codons that are translated into 3 amino acids

• 3 codons that are translated into 9 amino acids

• 3 codons that are translated into 3 polypeptides

• 9 nucleotides that are translated into 9 amino acids

Velma is developing a computer model of translation. Her instructor points out that the model does not include ribosomes or ribosomal RNA.

If the model is accurate in other ways, how does the absence of ribosomes and ribosomal RNA affect it?

• Certain amino acids would be missing from the polypeptides.

• The polypeptides would be much longer than normal.

• Amino acids would be joined together in an incorrect order.

• Amino acids would not join together, and no polypeptides would form.

Percy is studying the diagram shown here. The diagram is one fourth of a larger diagram that explains the genetic code.

By studying the diagram, Percy would be MOST LIKELY be able to construct an answer to which of these questions?

• How many codons make up a typical mRNA molecule?

• Are specific codons associated with introns and exons?

• Which amino acid is most common in a typical protein?

• Are all codons translated into amino acids?

What is the significance of this genetic code?

• It describes how DNA is transcribed to RNA.

• It describes how RNA is translated to amino acids.

• It describes how RNA is translated to genes.

• It describes how proteins are translated to RNA.

• It describes how RNA is translated to DNA.

Two scientists are both studying RNA. One scientist is studying RNA in mice and the other is studying RNA in E. coli bacteria. Which of the following best describes how each scientist would use a genetic code?

• Both scientists would use the same genetic code because all organisms have RNA.

• Both scientists would use the same genetic code because in all organisms the code is read three bases at a time and in the same direction.

• The scientists would use different genetic codes because different genes are expressed in mice and E. coli.

• 
  The scientist studying mice would use the genetic code for mice and the scientist studying E. coli would use the genetic code for E. coli because mice are more complex multicellular organisms.

• The scientist studying mice would use the genetic code for eukaryotes and the scientist studying E. coli would use the genetic code for prokaryotes because they each have different types of chromosomes.

DNA carries the information needed to make proteins. How is this information used to make proteins?

• Ribosomes "read" the DNA and translate each group of three nucleotides into amino acids to build proteins, with the help of mRNA and tRNA.

• DNA is transcribed into mRNA. Ribosomes "read" the mRNA and translate each group of three nucleotides into amino acids to build proteins, with the help of tRNA.

• mRNA is transcribed into tRNA. Ribosomes "read" the tRNA and translate each group of three nucleotides into amino acids to build proteins.

• DNA is transcribed into tRNA. Ribosomes "read" the tRNA and translate each group of three nucleotides into amino acids to build proteins, with the help of mRNA.

• DNA is transcribed into ribosomes. tRNA "reads" the ribosomes and translates each group of three nucleotides into amino acids to build proteins.

Which of the following is the BEST description of this diagram and what it represents?

• The bacterial genetic code, which uses U instead of T, representing how a sequence of three nucleotides in DNA codes for an amino acid.

• The eukaryotic genetic code, which uses U instead of T, representing how a sequence of three to six nucleotides in DNA codes for an amino acid.

• 
  The universal genetic code, representing how a sequence of three to six nucleotides in DNA codes for an amino acid.

• The universal genetic code, representing how a sequence of three nucleotides in RNA codes for an amino acid.

• The genetic code, represented by a transfer RNA molecule with nucleotides on the inside and amino acids on the outside.