lab exam 2

Question 1

is transferred from one bacterium to another in solution.

Answer 1

“naked” DNA

Question 2

are released as double-stranded DNA into the medium.

Answer 2

DNA fragments

Question 3

cut the double-stranded DNA in solution and the resulting fragments separate—only single-stranded molecules are transferred.

Answer 3

Endonucleases

Question 4

is spliced into the recipient cell’s DNA.

Answer 4

The transferred DNA

Question 5

Transformation

Answer 5

occurs naturally among some bacteria. It is used in the laboratory to create recombinant DNA and is also used to study the effects of introducing DNA into a cell, and in mapping gene locations.

Question 6

naked DNA
DNA Fragments
endonucleases
and transferred DNA are found in what process

Answer 6

transformation

Question 7

is transferred from one bacterium to another via a “bacteriophage” and then incorporated into the recipient’s DNA

Answer 7

DNA during transduction

Question 8

The bacterial virus may be

Answer 8

virulent or temperate.

Question 9

Bacteriophages contain either

Answer 9

RNA or DNA

Question 10

Some have taillike structure through w/ they inject their nucleic acid into the bacterial host cell.

Answer 10

bacteriophage

Question 11

bacteriophage is used in what process to transfer DNA

Answer 11

transduction

Question 12

If infecting virus (x) within the host cell & destroys it, the virus is said to be

Answer 12

“lytic or virulent”.

Question 13

. If virus does not replicate but rather “integrates” into the bacterial chromosome, virus is said to be

Answer 13

“temperate/lysogenic

Question 14

During conjugation the DNA is transferred

Answer 14

horizontally to cells without those cells undergoing replication

Question 15

DNA is transferred from one live bacterium to another through what during conjugation

Answer 15

direct contact: large quantities of DNA can be transferred in this way.

Question 16

F factors—

Answer 16

plasmids transferred from a donor cell (an F+) to a recipient cell (an F- cell) during conjugation

Question 17

An Hfr (high frequency of recombination) is a cell with

Answer 17

with an F plasmid incorporated into the chromosome .

Question 18

Before a cell can undergo “mitosis”, it must first duplicate its

Answer 18

genetic material

Question 19

In the process, called DNA replication, the

Answer 19

original (parent) DNA strand acts as a template for the synthesis of a complementary (daughter) strand.

Question 20

The first step in DNA synthesis is

Answer 20

unwinding or denaturation of the double-helix structure so replication may be carried out on each strand simultaneously, and bidirectionally. A variety of enzymes are required fro the “Replication” process.

Question 21

Transposons

Answer 21

small DNA segments that can move from one part of the chromosome to another area on either the same chromosome, a different chromosome, or a plasmid.

Question 22

Simple Transposons or insertion

Answer 22

is a short segment of DNA contain only those genes coding for the enzymes responsible for its transposition.

Question 23

Complex transposons

Answer 23

can carry any type of gene.

Question 24

DNA Helicase enzyme—are responsible

Answer 24

“unwinding the DNA helix” Unwinding the DNA helix increases coiling ahead of the replication fork, called supercoiling.

Question 25

Topoisomerases-are

Answer 25

enzymes that “cut” one or both of the DNA strands to relieve the increased tension of unwinding the DNA helix & subsequently reseal the “cut ends”.

Question 26

DNA polymerases

Answer 26

are enzymes that replicate complementary strands of DNA.DNA cannot replicate without RNA. DNA creates a model of the amino acids it needs by making a strand of mRNA.

Question 27

RNA Polymerase

Answer 27

is used in the synthesis of transfer RNA. Transfer RNA (tRNA) collects amino acids from the cell’s cytoplasm and carries them back to mRNA for inclusion.

Question 28

DNA ligase-is used in both

Answer 28

DNA repair and DNA replication. DNA ligases are essential for the joining of “Okazaki Fragments” during replication, & for completing short-patch DNA synthesis occurring in DNA repair process

Question 29

Gene Recombination

Answer 29

involves the exchange of genetic material either between multiple chromosomes or between different regions of the same chromosome.

Question 30

Recombination is used in DNA repair (particularly in

Answer 30

the repair of double-stranded breaks, As well as during DNA replication to assist in filling gaps & preventing stalling of the replication fork.

Question 31

The Operon Model

Answer 31

is a group of genes coding for related proteins and arranged in units. An Operon consist of an; operator, promoter, regulator, and structural genes.

Question 32

The regulator gene codes for a

Answer 32

repressor protein that binds to the operator, obstructing the promoter (thus transcription) of the structural genes.

Question 33

Enzymes Induction

Answer 33

is the process in which it initiates or enhances the expression of an enzyme

Question 34

ames test

Answer 34

method that uses bacteria to test whether a given chemical can cause mutations in the DNA of the test organism. More formally, it is a biological assay to assess the mutagenic potential of chemical compounds

Question 35

bacteriocins

Answer 35

are proteinaceous or peptidic toxins produced by bacteria to inhibit the growth of similar or closely related bacterial strain(s). They are similar to yeast and paramecium killing factors

Question 36

thermus aquaticus

Answer 36

Thermus aquaticus is a species of bacteria that can tolerate high temperatures, one of several thermophilic bacteria that belong to the Deinococcus–Thermus group.

Question 37

southern blot

Answer 37

combines transfer of electrophoresis-separated DNA fragments to a filter membrane and subsequent fragment detection by probe hybridization.

Question 38

metagenomics

Answer 38

is the study of genetic material recovered directly from environmental samples.