Q3 Review Part 3

Which among the following statement is TRUE about the structural difference between DNA and RNA?

• DNA is double stranded, while RNA is single stranded.

• DNA has ribose sugar, while RNA has deoxyribose sugar.

• The nitrogenous bases of DNA are A, U, G, C; while RNA has A, T, C, G.

• Both DNA and RNA are considered nucleic acid with nucleoside as a building block.

Which statement is supported by the following illustration?

• 1 is translation.

• 2 is transcription.

• 2 is DNA replication.

• 3 is DNA replication.

Given the DNA molecule base sequence C-C-G-T-C-T-A-C-C, what will be its mRNA and tRNA sequence respectively?

• mRNA: G-G-C-A-G-A-U-G-G; tRNA: C-C-G-U-C-T-A-C-C

• mRNA: G-G-C-C-A-G-A-U-G-G; tRNA: C-C-G-G-U-C-U-A-C-C

• mRNA: G-G-C-A-G-A-T-G-G; tRNA: C-C-G-T-C-A-A-C-C

• mRNA: G-C-C-A-G-A-T-G-G; tRNA: C-C-G-T-C-A-A-C-C

According to the rule on complementary pairing of nucleotide bases, adenine (A) will only make a bond with (a)   in DNA.

• cytosine

• guanine

• thymine

• uracil

In the accompanying table, which amino acid sequence would most likely be determined by a section of a DNA molecule with the base sequence: C-C-G-T-C-T-A-C-C?

• alanine-arginine-tryptophan

• arginine – leucine – tryptophan

• alanine – arginine – leucine

• tryptophan – leucine – arginine

What is the primary role of tRNA during protein synthesis?

• It transcribes the DNA sequence into mRNA.

• It carries the genetic code to the ribosome.

• It catalyzes the formation of peptide bonds between amino acids.

• It delivers specific amino acids to the ribosome based on the codon sequence.

A scientist observes that a protein is not being synthesized in a cell, even though the mRNA for that protein is present. Which of the following is the most plausible explanation?

• The cell lacks sufficient tRNA molecules.

• The cell has stopped transcription of the gene.

• The DNA sequence encoding the protein has a mutation.

• The ribosome is unable to recognize the mRNA due to a problem in the cap or tail of the mRNA.

Which of the following best describes the process of translation?

• It involves converting mRNA into a complementary DNA strand.

• It occurs in the nucleus and synthesizes RNA from DNA.

• It takes place in the ribosome, where mRNA is decoded to form a protein.

• It involves splicing out introns and connecting exons in the nucleus.

If the DNA varies from the normal DNA and becomes TAC-CCC-GTC-CAC-CGC-CTA-TAT-C, what will happen to the overall phenotypic expression of the given DNA sequence?

• There will be no change to the amino acid sequence.

• The phenotypic expression will differ from the normal due to a frameshift mutation that leads to missense mutation.

• The phenotypic expression will differ from the normal due to a frameshift mutation that leads to nonsense mutation.

• The phenotypic expression will differ from the normal due to a frameshift mutation that leads to silent mutation.

What type of mutation is exhibited if the DNA varies from the normal DNA and becomes TAC-CCC-GTC-CAC-CGC-CTA-TAT-C?

• Deletion

• Insertion

• Inversion

• Translocation