DNA Replication and Transcription Quiz

Which of the following events occurs in transcription as well as in replication of DNA?

• Free nucleotides bond to the DNA strand.

• Two new DNA molecules are produced.

• Uracil nucleotides bond to adenine on the DNA strand.

• Only part of the DNA molecule containing a gene unwinds.

The following diagram shows the structure of a tRNA molecule. Which letter A, B, C or D, indicates the position on the molecule where the amino acid would be attached?

Which of the following represents the sequence of amino acids in the polypeptide chain from the DNA strand?

• Serine -Lysine -Histidine -Phenylalanine -Glycine -Tyrosine

• Serine -Phenylalanine -Alanine - Lysine -Histidine -Tyrosine

• Tyrosine -Glycine -Phenylalanine -Histidine -Lysine -Serine

• Tyrosine -Histidine -Lysine -Alanine -Phenylalanine -Serine

Which of the following BEST explain why DNA replication is important in maintaining genetic stability?

• I. DNA has to replicate accurately to allow offspring to inherit genes from parents.

• II. When new cells are made, each must receive two exact copies of the instructions to function properly.

• III. DNA must be replicated for cell division to produce cells that function efficiently.

• I, II and III

Which of the following is NOT a feature of the genetic code?

• Similar amino acids may have similar codons.

• A triplet of bases codes for one amino acid in a polypeptide chain.

• One amino acid may be coded for by more than one codon.

• Each species has its own set of unique triplet codes

give a concise description of the events occuring at the steps labelled 1,2 and 3 in the diagram (6 marks)

One role of transfer RNA in protein synthesis is to

• Deliver amino acids to ribosomes

• Terminate the elongation of the polypeptide chain

• Acts as a supporting framework for polypeptide chains

• Carry protein-building instructions from DNA in the cytoplasm

What is the primary function of ribosomal RNA in protein synthesis?

• To transport amino acids to the ribosome

• To catalyze the formation of peptide bonds

• To carry genetic information from DNA

• To provide a site for protein synthesis

Which of the following statements about codons is TRUE?

• Codons are found in the mRNA sequence.

• Each codon consists of four nucleotides.

• Codons are identical in all organisms.

• Each codon codes for multiple amino acids.

During which phase of the cell cycle does DNA replication occur?

• M phase

• G2 phase

• S phase

• G1 phase