Chapter 8: Microbial Genetics

Positive

Positive

________ (direct) selection involves the detection of mutant cells by rejection of the unmutated parent cells.

Transcription

________ is the synthesis of a complementary strand of RNA from a DNA template.

genetic makeup

The genotype of an organism is its ________- all its DNA- the information that codes for all the particular characteristics of the organism.

Phenotype

________ refers to actual, expressed properties, such as the organisms ability to perform a particular chemical reaction.

eukaryotic genes

Thus, ________ are composed of exons, the regions of DNA expressed, and introns, the intervening regions of DNA that do not encode protein.

donor

In all of the mechanisms, the transfer involves a(n) ________ cell that gives a portion of its total DNA to a recipient cell.

Chromosomes

________ are structures containing DNA that physi- cally carry hereditary information; the ________ contain the genes.

E coli

Noncoding regions called short tandem repeats (STRs) occur in most genomes, including that of ________.

STRs

________ are repeating sequences of two- to five- base sequences.

survival of new genotypes

The ________ is called natural selection.

mutation

A(n) ________ is a permanent change in the base sequence of DNA.

Any mutant microorganism

________ having a nutritional requirement that is absent in the parent is known as an auxotroph.

flow of genetic information

The ________ can be shown as flowing from DNA to RNA to proteins, as follows:

genetic code

The ________, the set of rules that determines how a nucleotide sequence is converted into the amino acid sequence of a protein.

excess tryptophan

When ________ is present, the tryptophan acts as a corepressor binding to the repressor protein.

repressible operons

In ________, the structural genes are transcribed until they are turned off.

science of heredity

Genetics is the ________.

Nucleotide excision repair

________ is not restricted to UV- induced damage; it can repair mutations from other causes as well.

Genetic recombination

________ refers to the exchange of genes between two DNA molecules to form new combinations of genes on a chromosome.

tRNA molecule

Each ________ has an anticodon, a sequence of three bases that is complementary to a codon.

Messenger RNA

________ (mRNA) carries the coded information for making specific proteins from DNA to ribosomes, where proteins are synthesized.

genetic information

The ________ in a cell is called the genome.

Transcription

________ begins when RNA polymerase binds to the DNA at a site called the promoter.