6. Which of the following statements regarding genetic code is correct?
(A) Multiple codons can encode one amino acid.
(B) Genetic code is shared by organisms from the simplest bacteria to higher animals.
(C) Scientists can reprogram the amber codon to encode unnatural amino acids.
(D) All of the above.
(E) None of the above.

2. Which of the following is not part of a tRNA cloverleaf structure? (A) codon arm (B) acceptor arm (C) anticodon arm (D) D arm (E) extra arm

3. A phage can transfer its genome or a DNA molecule to a bacterial cell. This process is called (A) transformation (B) conjugation (C) transduction (D) recombination (E) accommodation

4. Which of the following enzymatic activities is not found in natural DNA polymerases? (A) 5' to 3' polymerase (B) 3' to 5' polymerase (C) 5' to 3' exonuclease (D) 3' to 5' exonuclease (E) strand-displacement activity

5. Which of the following statements regarding transposons is not correct? (A) Transposons can move from one position to another on the genome. (B) Transposons can propagate themselves within the genome. (C) Insertion sequences are a type of transposons. (D) Transposons can be transcribed into RNAs. (E) Transposons are non-coding DNAs.

7. Which of the following statements regarding DNA packaging is not correct? (A) Histone phosphorylation affects chromatin structure. (B) Heterochromatin is a tightly packed form of DNA. (C) Insulator provides a barrier that protects against the inactivating effect from heterochromatin. (D) Centromeric DNA is normally in a heterochromatin state. (E) During mitosis, securin holds sister chromatids together.

8. Which of the following statements regarding telomere is not correct? (A) Telomere lies at the end of a chromosome. (B) Each telomere consists of a long series of short, tandemly repeated sequences. (C) Telomerase is a large ribonucleoprotein with a templating RNA and a protein with catalytic activity. (D) Ectopic expression of human telomerase reverse transcriptase (hTERT) can be used to immortalize primary cells. (E) hTERT is often down-regulated in rapidly dividing stem cells.

9. Which of the following statements regarding introns is not correct? (A) Introns are removed when primary transcript is processed to give mature RNA. (B) Intron junctions are defined by the GU-AG rule: starts with the dinucleotide GU and ends with the dinucleotide AG. (C) As genome size increases, the tendency is for exons to become large and introns remain small. (D) Aptamers can be used to control intron splicing. (E) Many animal micro RNA (miRNA) genes are located in introns of protein-coding genes.

10. Which of the following statements regarding p53 is not correct? (A) It is a tumor suppressor. (B) It is a DNA-binding protein. (C) It is a stable protein with half-life of several hours. (D) Its activation can lead to cell cycle arrest. (E) It can activate apoptosis.

1. Which of the followings is NOT a component of DNA? (A) Ribose (B) Base A, T, C, or G (C) 5'-phosphate group (D) 3' hydroxyl group (E) Deoxyribose

複選題2. Which of the following enzymes are required in DNA replication of prokaryotes? (A) DNA gyrase (B) Helicase (C) Methyltransferase (D) Primase (E)DNA ligase