7. Genetic Transfer and Mapping in Bacteria

Question 1

the transfer of genetic material from one bacterial cell to another.

Answer 1

Genetic Transfer

Question 2

a form of genetic transfer between bacteria that involves direct physical interaction between two bacterial cells. One bacterium acts as donor and transfers genetic material to a recipient cell.

Answer 2

Conjugation

Question 3

1) when a bacterial cell takes up a plasmid vector or segment of chromosomal DNA from the environment; (2) when a normal cell is converted into a malignant cell.

Answer 3

Transformation

Question 4

a form of genetic transfer between bacterial cells in which a virus (bacteriophage) transfers bacterial DNA from one bacterium to another.

Answer 4

Transduction

Question 5

a type of growth medium for microorganisms that contains a mixture of nutrients that are required for growth; nothing additional has been added.

Answer 5

Minimal Medium

Question 6

a strain that cannot synthesize a particular nutrient and needs that nutrient to be added to its growth medium.

Answer 6

Auxotroph

Question 7

a strain that does not need a particular nutrient included in its growth medium.

Answer 7

Prototroph

Question 8

a fertility factor that is found in certain strains of bacteria and carries genes that allow the bacteria to conjugate. Strains of bacteria that contain an F factor are designated F+; strains without any F factor are designated F−.

Answer 8

F Factor

Question 9

a structure on the surface of bacterial cells that acts as an attachment site to promote the binding of bacteria to each other.

Answer 9

Sex Pilus (Pili)

Question 10

a connection between two bacterial cells that provides a passageway for DNA during conjugation.

Answer 10

Conjugation Bridge

Question 11

a protein complex that recognizes the origin of transfer in F factors and other conjugative plasmids, cuts one DNA strand, and aids in the transfer of the T DNA.

Answer 11

Relaxosome

Question 12

the location on an F factor or within the chromosome of an Hfr strain that is the initiation site for the transfer of DNA from one bacterium to another during conjugation.

Answer 12

Origin of Transfer

Question 13

(1) during conjugation, the strand of F-factor DNA that is transferred to a recipient cell; (2) a segment of DNA found within a Ti plasmid that is transferred from a bacterium to an infected plant cell.

Answer 13

T DNA

Question 14

a complex of DNA (or RNA) and a protein.

Answer 14

Nucleoprotein

Question 15

a general term for a DNA molecule (most often circular) that exists independently of the chromosomal DNA. Some are used as vectors in cloning experiments.

Answer 15

Plasmids

Question 16

a genetic element that can replicate independently of the chromosomal DNA but can also occasionally integrate into the chromosomal DNA.

Answer 16

Episome

Question 17

a bacterial strain in which an F factor has become integrated into the bacterial chromosome. During conjugation, an Hfr strain can transfer segments of the bacterial chromosome

Answer 17

Hfr (High frequency of recombination) Strain

Question 18

an F factor that also carries genes derived from the bacterial chromosome.

Answer 18

F’ (prime) Factors

Question 19

a method used in conjugation experiments in which the length of time that the bacteria spend conjugating is stopped by a blender treatment or other type of harsh agitation.

Answer 19

Interrupted Mating

Question 20

a unit of measure used in bacterial conjugation experiments; refers to the relative time it takes for genes to first enter a recipient strain during conjugation.

Answer 20

Minute

Question 21

a virus that infects bacteria.

Answer 21

Bacteriophage (Phage)

Question 22

a type of growth cycle for a bacteriophage in which the phage directs the synthesis of many copies of its genetic material and coat proteins. These components then assemble to make new phages. When synthesis and assembly are completed, the bacterial host cell is lysed, and the newly made phages are released into the environment.

Answer 22

Lytic Cycle

Question 23

a natural process of transformation that occurs in certain species of bacteria.

Answer 23

Natural Transformation

Question 24

cells that can take up DNA from the environment or an extracellular medium.

Answer 24

Competent Cells

Question 25

proteins that are needed for bacterial cells to become naturally transformed by extracellular DNA.

Answer 25

Competence Factors

Question 26

the exchange of identical or similar DNA segments between homologous chromosomes.

Answer 26

Homologous Recombination

Question 27

a region of double-stranded DNA that contains one or more base mismatches.

Answer 27

Heteroduplex

Question 28

the exchange of DNA between nonhomologous segments of chromosomes or plasmids.

Answer 28

Nonhomologous Recombination

Question 29

transformation of bacteria that occurs via experimental treatments.

Answer 29

Artificial Transformation

Question 30

a peptide secreted by certain species of bacteria that allows them to become competent for transformation.

Answer 30

Competence-Stimulating Peptide (CSP)

Question 31

DNA sequences found in certain species of bacteria that are needed for a DNA fragment to be taken up during transformation.

Answer 31

DNA Uptake Signal Sequences

Question 32

the transfer of genes from one individual to another individual that is not its offspring.

Answer 32

Horizontal Gene Transfer

Question 33

the acquisition of antibiotic resistance by a bacterial strain, which may result from genetic alterations in the bacterial genome, but often occurs because a bacterium has taken up a gene or plasmid from another bacterial strain.

Answer 33

Acquired Antibiotic Resistance