Nucleic acids and protein synthesis：練習問題

Which of the following correctly identifies the three components that make up a single DNA nucleotide?

Following transcription in a eukaryotic cell, the primary transcript undergoes modification to form mature mRNA. Which statement correctly identifies the purpose and result of this modification?

Which statement best explains why a deletion mutation of a single base pair in the middle of a gene is generally more harmful to the resulting polypeptide than a substitution mutation?

Which set of components is found in a molecule of RNA but not in a molecule of DNA?

A sample of DNA was analyzed and found to contain 22% cytosine. What is the expected percentage of adenine in this same DNA sample?

Identify the type of covalent bond that links nucleotides together in a DNA strand and state which part of the pentose sugar is involved in this bond.

Explain why DNA polymerase can only synthesize new strands in a \( 5' \) to \( 3' \) direction and how this leads to the formation of Okazaki fragments on the lagging strand.

A specific segment of DNA contains the base sequence 5'-GAT-3' on the template strand. Deduce the corresponding anticodon sequence on the tRNA molecule and describe the hydrogen bonding that would occur between the codon and anticodon.

DNA is a polynucleotide with a specific double-helical structure.
(a) State the three components of a single DNA nucleotide.
(b) Explain the importance of hydrogen bonding in maintaining the structure of a DNA molecule.

A specific segment of DNA has the following base sequence on its transcribed strand:
3'-T A C G G G A T T T C C-5'

(a) Determine the sequence of the mRNA molecule produced during transcription and the sequence of the non-transcribed DNA strand.
(b) Describe the role of RNA polymerase in ensuring the accuracy of this sequence during the formation of the primary transcript.