Exam 3 Version 1 Flashcards
What is a promoter?
A DNA sequence that is needed for the initiation of transcription
Which type of RNA is NOT involved in the process of translation?
All of the above are involved in translation
(includes mRNA, rRNA, and tRNA)
There are 61 ___ codons in the genetic code
Sense
What complex is responsible for the formation of peptide bonds between amino acids?
Ribosome
The role of tRNA is to deliver _______ during protein synthesis
An amino acid
Choose the best answer
Both A + B:
A: Multiple copies of an mRNA can be produced from the same gene
B: Multiple copies of a protein can be produced from the same mRNA
Which of the following processes does NOT depend on complementary base pairing?
Protein folding
A gene that is _______ is ‘on’ at all times
Constitutively expressed
Which of the following statements about operons is INCORRECT?
Structural genes within an operon are transcribed independently of one another
In an inducible operon, an inducer binds to the ________, pulling it off the operator and enabling transcription of the structural genes
Repressor
If the lac operator was deleted from the lac operon
lacZYA would be expressed regardless of lactose concentration
The structural genes in the lac operon are involved in the ____ of lactose. The structural genes in the trp operon are involved in the _____ of tryptophan
Breakdown, synthesis
In a repressible operon, a(n) ________ binds to the repressor, which prevents transcription of the structural genes
Co-repressor
Which of the following statements about mutations is FALSE
Mutations always have a negative effect on the fitness of an organism
Which of the following types of mutations is least likely to have an impact on the function of the encoded protein?
Synonymous
A gene that moves to various different sites within a bacterial chromosome is likely positioned within a
Transposon
Which of the following statements regarding plasmids is FALSE
Plasmids encode essential genes
Horizontal gene transfer is a mechanism for bacterial populations to
Generate genetic diversity
Horizontal gene transfer refers to DNA that is
Acquired from an external source
If a bacterial cell is competent, it means that
The bacterium can import free DNA fragments and incorporate them into its genome
Which of the following is encoded within a conjugative plasmid
Sex pilus
Which of the following describes an F factor that has integrated into a bacterial chromosome?
Hfr
Which of the following is necessary for the integration of foreign DNA into a host chromosome?
Recombination
Which of the following is NOT an example of biotechnology?
Determining the ultrastructure of flagellar motors
Methylation protects bacterial DNA from degradation due to _________
Restriction enzymes
The enzyme BamHI recognizes the sequence 5’-GGATCC-3’ and cuts between the ‘GG’ within the sequence to produce a sticky end. What single-stranded overhang is produced as a result? (hint: DNA is double stranded)
5’-GATC-3’
Which of the following steps is NOT a part of a PCR cycle?
Methylation
How is progression through the steps and cycles of PCR controlled?
Change in temperature
Several characteristics make E. coli and S.cerevisiae excellent model systems for recombinant DNA technology. Which of the following is NOT a reason?
Both are pathogenic
What taxonomic ranks are included in binomial nomenclature?
Genus and species
In biology, the current taxonomic system is based on _______
Evolutionary relatedness
The species concept loses meaning when discussing bacteria because
Bacteria reproduce asexually rather than sexually
Which of the following organelles is thought to have evolved from prokaryotic cells?
Mitochondrion
All organisms require carbon but some organisms can only utilize carbon in certain chemical forms. The indicates the importance of
Biogeochemical cycling
Algal blooms are caused by
Influx of nutrients
Which food preservation method works by reducing the number of microbes present?
Pasteurization
Why is boiling food contaminated by Clostridium botulinum ineffective for preventing botulism?
The botulism toxin is heat stable
Which of the following is NOT a benefit of food fermentation?
Elimination of all microbes
What primary reaction occurs during the fermentation of milk?
Carbohydrates –> lactic acid
All of the following are essential components of chocolate production EXCEPT
Alkaline fermentation by mold (eg. Rhizopus)
[review 3 mechanisms of HGT: transformation ,conjugation, transduction]
