Chapter 11 – Test Yourself
Questions
1. In the semiconservative model of DNA replication, each daughter molecule comprises
one ____________ strand and one newly-synthesised strand.
2. During DNA replication, the point where the two strands become separated is called
the ____________ ____________.
3. DNA polymerase III forms a second strand by adding complementary nucleotides
in the

direction.
4. During DNA replication, the ____________ ____________ must be synthesised
discontinuously, as a series of ____________ fragments.
5. Mistakes in DNA replication are largely corrected by the cell’s ____________ enzymes. Any
errors that persist may lead to ____________.
6. The function of genes was expressed in the one ____________, one ____________
hypothesis.
7. The flow of information: DNA  mRNA  protein is often referred to as the ____________
____________ of biology.
8. In the genetic code, many amino acids are encoded by more than one triplet sequence; the
code is therefore said to be ____________. Three of the ____________ triplet combinations
do not code for an amino acid, but instead serve as ____________ codons.
9. The enzyme RNA polymerase uses a single-stranded ____________ template to synthesise a
complementary strand of ____________ ____________.
10. Transcription begins at a ____________ sequence, situated ___________ of the gene.
11. In bacteria, proteins with related functions may be encoded together; the result of
transcription is a ____________ mRNA.
12. In eukaryotes, genes are usually discontinuous; coding regions called ____________ are
interspersed with non-coding ____________.
13. Molecules of tRNA act as adapter molecules during translation; at one end they have a three
base ____________ complementary to a triplet codon, and at the other end carry the
corresponding ____________ ____________.
14. Lactose acts as an ____________ for the three genes that make up the lac operon. It
neutralises the effects of a ____________ protein encoded by the I gene.
15. The trp operon contains five genes involved in the synthesis of ____________. The
presence of this substance activates a ____________, which prevents transcription of the
operon by binding to the ____________ sequence.
16. A ____________ mutation alters the ____________ ____________ of a gene and will
change the sense of the encoded message. Such a mutation arises through a ____________
or ____________ of DNA.
17. A ____________ mutation changes a normal codon into a ____________ codon, and results
in the premature termination of translation.
18. ____________ ____________ such as 5-bromouracil mimic the structure of normal
nucleotide bases and become ____________ into the DNA structure.
19. The ____________ test is used to assess the mutagenicity of a substance.
Essential Microbiology, Second Edition. Stuart Hogg.
© 2013 John Wiley & Sons, Ltd. Published 2013 by John Wiley & Sons, Ltd.
20. In Griffith’s famous experiment, ____________-____________ cells of the virulent S-strain
appeared to pass on the ability to synthesise a capsule to the no-virulent R-strain.
21. Transformation only occurs between related cells as it depends on the donor DNA finding a
____________ sequence on the host chromosome with which to ____________.
22. ____________ ____________ experiments can be used to map the order in which genes on
a bacterial chromosome are transferred by conjugation.
23. In ____________ transduction, chromosomal genes close to the point of integration of the
____________ may be excised along with it and be transferred to another host cell.
24. In ____________ transduction, fragments of ____________ DNA are mistakenly packaged
into phage coats and can be transferred to another bacterial cell.
25. ____________ ____________ are sequences of DNA that can move from one location on a
chromosome to another.
Chapter 11 – Test Yourself
Answers
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parental
replication fork
5’3’
lagging strand, Okazaki
Proofreading, mutations
gene, enzyme
central dogma
degenerate, 64, stop
DNA, messenger RNA
promoter, upstream
polycistronic
exons, introns
anticodon, amino acid
inducer, repressor
tryptophan, repressor, operator
frameshift, reading frame, insertion, deletion
nonsense, stop
base analogues, incorporated
Ames
heat-killed
homologous, recombine
interrupted mating
specialised, prophage
generalised, chromosomal
transposable elements
Essential Microbiology, Second Edition. Stuart Hogg.
© 2013 John Wiley & Sons, Ltd. Published 2013 by John Wiley & Sons, Ltd.