MCQ Microbiology
MCQ Biochemistry of Genome
1. Frederick Griffith infected mice with a combination of dead R and live S bacterial strains. What was the outcome, and why did it occur?
a) The mice will live. Transformation was not required.
b) The mice will die. Transformation of genetic material from R to S was required.
c) The mice will live. Transformation of genetic material from S to R was required.
d) The mice will die. Transformation was not required.
2. Why was the alga Acetabularia a good model organism for Joachim Hämmerling to use to identify the location of genetic material?
a) It lacks a nuclear membrane.
b) It self-fertilizes.
c) It is a large, asymmetrical, single cell easy to see with the naked eye.
d) It makes a protein capsid.
3. Which of the following best describes the results from Hershey and Chase’s experiment using bacterial viruses with 35S-labeled proteins or 32P-labeled DNA that are consistent with protein being the molecule responsible for hereditary?
a) After infection with the 35Slabeled viruses and centrifugation, only the pellet would be radioactive.
b) After infection with the 35S-labeled viruses and centrifugation, both the pellet and the supernatant would be radioactive.
c) After infection with the 32P-labeled viruses and centrifugation, only the pellet would be radioactive.
d) After infection with the 32P-labeled viruses and centrifugation, both the pellet and the supernatant would be radioactive.
4. Which method did Morgan and colleagues use to show that hereditary information was carried on chromosomes?
a) statistical predictions of the outcomes of crosses using truebreeding parents
b) correlations between microscopic observations of chromosomal movement and the characteristics of offspring
c) transformation of nonpathogenic bacteria to pathogenic bacteria
d) mutations resulting in distinct defects in metabolic enzymatic pathways
5. According to Beadle and Tatum’s “one gene–one enzyme” hypothesis, which of the following enzymes will eliminate the transformation of hereditary material from pathogenic bacteria to nonpathogenic bacteria?
a) carbohydrate-degrading enzymes
b) proteinases
c) ribonucleases
d) deoxyribonucleases
6. Which of the following is not found within DNA?
a) thymine
b) phosphodiester bonds
c) complementary base pairing
d) amino acids
7. If 30% of the bases within a DNA molecule are adenine, what is the percentage of thymine?
a) 20%
b) 25%
c) 30%
d) 35%
8. Which of the following statements about base pairing in DNA is incorrect?
a) Purines always base pairs with pyrimidines.
b) Adenine binds to guanine.
c) Base pairs are stabilized by hydrogen bonds.
d) Base pairing occurs at the interior of the double helix.
9. If a DNA strand contains the sequence 5ʹ- ATTCCGGATCGA-3ʹ, which of the following is the sequence of the complementary strand of DNA?
a) 5ʹ-TAAGGCCTAGCT-3ʹ
b) 5ʹ-ATTCCGGATCGA-3ʹ
c) 3ʹ-TAACCGGTACGT-5ʹ
d) 5ʹ-TCGATCCGGAAT-3ʹ
10. During denaturation of DNA, which of the following happens?
a) Hydrogen bonds between complementary bases break.
b) Phosphodiester bonds break within the sugar-phosphate backbone.
c) Hydrogen bonds within the sugarphosphate backbone break.
d) Phosphodiester bonds between complementary bases break.
11. Which of the following types of RNA codes for a protein?
a) dsRNA
b) mRNA
c) rRNA
d) tRNA
12. A nucleic acid is purified from a mixture. The molecules are relatively small, contain uracil, and most are covalently bound to an amino acid. Which of the following was purified?
a) DNA
b) mRNA
c) rRNA
d) tRNA
13. Which of the following types of RNA is known for its catalytic abilities?
a) dsRNA
b) mRNA
c) rRNA
d) tRNA
14. Ribosomes are composed of rRNA and what other component?
a) protein
b) carbohydrates
c) DNA
d) mRNA
15. Which of the following may use RNA as its genome?
a) a bacterium
b) an archaeon
c) a virus
d) a eukaryote
16. Which of the following correctly describes the structure of the typical eukaryotic genome?
a) diploid
b) linear
c) singular
d) double stranded
17. Which of the following is typically found as part of the prokaryotic genome?
a) chloroplast DNA
b) linear chromosomes
c) plasmids
d) mitochondrial DNA
18. Serratia marcescens cells produce a red pigment at room temperature. The red color of the colonies is an example of which of the following?
a) genotype
b) phenotype
c) change in DNA base composition
d) adaptation to the environment
19. Which of the following genes would not likely be encoded on a plasmid?
a) genes encoding toxins that damage host tissue
b) genes encoding antibacterial resistance
c) gene encoding enzymes for glycolysis
d) genes encoding enzymes for the degradation of an unusual substrate
20. Histones are DNA binding proteins that are important for DNA packaging in which of the following?
a) double-stranded and singlestranded DNA viruses
b) archaea and bacteria
c) bacteria and eukaryotes
d) eukaryotes and archaea
