Biology ch7 connect

Relaxase

During conjugation, what protein remains bound to the single-stranded DNA that is transferred from the donor cell to the recipient cell?

-endonuclease/ enzyme -recombination

During transformation, a DNA fragment that has bound to a cell surface receptor is cut into smaller fragments by an extracellular_________. After the DNA has been taken up by the cell, it is incorporated into the bacterial chromosome by homologous __________.

between members of the same species or members of different species

Horizontal gene transfer is possible

By excision of an F factor from a bacterial chromosome.

How are F' factors produced?

Only F+ strains contain an F Factor.

How do F+ and F- strains of E. coli differ from one another?

temperature/ heat nutrients/ nutrient

the competence of a bacterial cell can be affect by environmental factors such as ionic conditions, _______, and the availability of ________.

conjugation

the genes that are carried on the F factors are required for

bridge

the passageway for DNA transfer between a donor cell and a recipient cell is called a conjugation _____

minute

the unit of measure that is used for the distance between two genes on a bacterial chromosome is the

False

True or false: transformation, the uptake of foreign DNA by bacterial cells, does not occur in nature, but it is possible in genetically engineered bacterial strains.

-It recognizes the origin of transfer in the F factor. -It separates the two strands of the F factor.

What are the functions of the relaxosome in conjugation?

Integration of an f factor into a bacterial chromosome

What event leas to the formation of an Hfr strain?

A DNA molecule that can exist independently of the bacterial chromosome.

What is a plasmid?

A plasmid that can integrate into a chromosome.

What is an episome?

Transfer of DNa to a recipient that is not the offspring of the donor organism

What is horizontal gene transfer?

They make contact with recipient cells.

What is the function of the sex pili during conjugation?

It allows the plasmid to be copied separately from the bacterial chromosome.

What is the significance of a plasmid's origin of replication?

Wollman and Jacob

What pair of scientists carried out the first genetic mapping experiments in bacteria in the 1950's?

depends on both the location and orientation of the origin of transfer

When Hfr strains are compared to one another, the order in which genes are transferred to recipient strains

artificial

When a scientist uses transformation to introduce foreign DNA into cells in the laboratory, it is called _______ transformation in order to distinguish this process from transformation that occurs naturally.

plasmid

A DNA molecule that can exist independently of the bacterial chromosome is called a(n)

nucleoprotein

A complex of DNA and protein is called a(n)

episome

A plasmid that can integrate into a chromosome is called a(n)

competent

A scientist might expose bacterial cells to an electrical field or treat them with calcium chloride followed by a heat shock in order to make the cells ________, which means able to take up DNA.

order

Based on the time it takes for different genes to be transferred from an Hfr strain to an F- strain, one can deduce the ________ of genes along the bacterial chromosome.

Hfr

DNA from the bacterial chromosome may be transferred from one cell to another if a(n) ________ cell conjugates with an F- cell.

relaxase

During conjugation, the DNA that is transferred is part of a nucleoprotein complex that contains single-stranded DNA and a protein called _____

relaxosome

During conjugation, the protein that recognizes the origin of transfer in the F factor, cuts one of the strands, and then separates two DNA strands is called the

origin of transfer

During conjugation, the starting point and direction of DNA transfer are determined by a DNA sequence within the F factor called the

unable to grow in the presence of either streptomycin or azide

If conjugation occurs between these two cells, transfer of the strs and azis genes from the her to the F- cell would be confirmed if the cells were

Only a short segment of the chromosome is transferred.

If the two cells undergo conjugation, but only for a short period of time, what is the likely outcome?

lacking both leucine and threonine

In a conjugation experiment between the two cells shown here, transfer of both the leu+ and thr+ genes could be monitored by growing the recipient cells on media_______

genes that are close to the origin of transfer

In an interrupted mating experiment, what genes will be transferred to the recipient cell first?

origin of replication

In order to be replicated independently of bacterial chromosome, a plasmid must have its own ________ of ________

stimulates nearby cells to express competence proteins

The competence-stimulating peptide of Streptococcus pneumonia

-incorporating DNa into the bacterial chromosome -allowing DNa fragments to bind to the surface of a bacterial cell -aiding the uptake of DNA into the cytoplasm of a bacterial cell

The functions of competence factors include

acquired

The phenomenon in which a bacterial strain that is susceptible to a specific antibiotic becomes resistant to that antibiotic is called _________ antibiotic resistance

False

True or False: Plasmids occur only in bacteria.

False

True or false: Most plasmids are linear.

When an Hfr strain conjugates with an F- strain

When does conjugation result in the transfer of part of the bacterial chromosome to the recipient cells?

Only one strand of the F factor DNA is transferred

Which of the following statements about conjugation is correct?

Transformation is a natural process that has evolved in some species of bacteria

Which of the following statements about transformation is correct?

DNa uptake signal sequence

Which type of sequence is found in the genomes of bacterial species such as neisseria meningitidis, neisseria gonorrhoeae, and haemophilus influenzae that enables recognition and uptake of dna from other cells of the same species?

interrupted

Wollman and Jacob used a blender to separate bacterial cells in the act of conjugation without killing the cells. Their technique is called______ mating

F+ ; F-

a strain of E. Coli that contains an F factor and can act as a conjugation donor is desigated__________, and a strain that lacks the F factor may be a recipient and is designated__________

competence-stimulating

a streptococcus pneumoniae cell may begin to express competence proteins if a nearby cell secretes the

recombination

after conjugation, a recipient cell may have a new combination of alleles if homologous ______ occurred between the transferred Hfr chromosome and the original chromosome of the bacterial cell.

transferring genes from its chromosome to F- strains.

an Hfr bacterial strain is very efficient at _______.

1, one, or single

during conjugation, the number of strands of the F factor DNA that is transferred from the donor cell to the recipient cell is____

lac+

if conjugation occurs between the two cells shown in this figure, which gene will be transferred first?

homologous recombination must occur

in order for a segment of transformed dna that carries a lys+ gene to be incorporated into a lys- cell _______.

the origin of transfer

what DNA sequence in the f factor is recognized and cut to begin the process of conjugation

a virus that infects bacteria

what is a bacteriophage?

a bacterial cell that can take up foreign DNA

what is a competent cell?

it promotes the transfer of dna among members of the same species

what is the function of the dna uptake signal sequence that is found in certain bacterial species, such as neisseria miningitidis, eisseria gonorrhoeae, and haemophilus influenzae?

genetic material surrounded by a protein coat

what is the structure of a bacteriophage?