Chapter 9

Question 1

Transduction

Answer 1

The process where a bacteriophage serves as the DNA carrier from a donor cell to a recipient cell

Question 2

Generalized transduction

Answer 2

Random fragments of disintegrating host DNA are taken up by the phage during assembly

Question 3

Transposons

Answer 3

Transposable elements that shift from one part of the genome to another and are termed “jumping genes”

Question 4

Transformation

Answer 4

Nonspecific acceptance by a bacterial cell of small fragments of soluble DNA from the surrounding environment; facilitated by special DNA-binding proteins on the cell wall that capture DNA from the surrounding medium

Question 5

Competent

Answer 5

Ella that are capable of accepting genetic material through transformation

Question 6

Redundancy or degeneracy

Answer 6

A particular amino acid can be coded for by more than one codon

Question 7

Wobble property

Answer 7

Thought to permit some variation or mutation without changing the message

Question 8

Start codon

Answer 8

AUG

Question 9

Nonsense or stop codons

Answer 9

Carry a necessary message instructing the enzyme to stop at a specific place

Question 10

Polyribosomal complex

Answer 10

An assembly line for mass production of proteins

Question 11

Introns

Answer 11

Do not code for proteins; several intervening sequences of triplets

Question 12

Exons

Answer 12

Translated into proteins; introns that are interspersed between coding regions

Question 13

Operons

Answer 13

A section of DNA that contains one or more structural genes along with a corresponding operator gene that controls transcription

Question 14

Inducible operons

Answer 14

The operon is turned on (induced) by the substrate of the enzyme for which the structural gene codes

Question 15

Repressible operons

Answer 15

Often contain genes codon for anabolic enzymes such as those used to synthesize amino acids

Question 16

Lactose (lac) operon

Answer 16

A system used to explain control through genetic induction; accounts for the regulation of lactose metabolism

Question 17

Regulator

Answer 17

Composed of the gene that coded for a protein capable of repressing the operon (a repressor)

Question 18

Operator

Answer 18

A sequence that acts as an on/off switch for transcription

Question 19

Allosteric

Answer 19

It’s shape can change depending on which active site and substrate are in play

Question 20

Inducer

Answer 20

Responsible for stimulating the chain of events leading to protein synthesis

Ex: lactose

Question 21

Corepressor

Answer 21

Slows the transcription of the operon

Question 22

Mutation

Answer 22

A phenotypic change due to an alteration in the genotype

Question 23

Wild type or wild strain

Answer 23

A microorganism that exhibits a natural, non mutated characteristic

Question 24

Mutant strain

Answer 24

A microorganism that bears a mutation; vary in morphology, nutritional characteristics, genetic control mechanisms, resistance to chemicals, temperature preference, and nearly any type of enzymatic function

Question 25

Spontaneous mutation

Answer 25

A random change in the DNA arising from errors in replication that occur without a known cause

Question 26

Induced mutations

Answer 26

Result from exposure to mutagens

Question 27

Mutagens

Answer 27

Physical or chemical agents that damage DNA and interfere with its functioning

Question 28

Point mutations

Answer 28

Latter mutations that involve addition, deletion, or substitution of single based

Question 29

Missense mutation

Answer 29

Any change in the code that leads to placement of a different amino acid; can do one of these:

1. Create a faulty, nonfunctional protein
2. Produce a protein that functions in a different manner
3. Cause no significant alteration

Question 30

Nonsense mutation

Answer 30

Changes a normal codon into a stop codon that doesn’t code for an amino acid and stops the production of the protein wherever it occurs

Question 31

Silent mutation

Answer 31

Alters a base but does not change the amino acid and has no effect

Question 32

Back-mutation

Answer 32

Occurs when a gene that has undergone mutation reverses (mutates back) to its original base composition

Question 33

Frameshift

Answer 33

The reading frame of the mRNA has been changed; nearly always result in the addition of deletion of amino acids

Question 34

The Ames test

Answer 34

A screening system to detect chemicals with carcinogenic potential

Question 35

Recombination

Answer 35

One bacterium donates DNA to another bacterium is a type of genetic transfer; resulting in a new strain different from the donor and original strains

Question 36

Recombinant

Answer 36

Any organism that has acquired genes that originated in another organism

Question 37

Plasmids

Answer 37

Small chromosomal fragments; circular pieces of DNA that contain their own origin of replication and therefore can replicate independently of the bacterial chromosome

Question 38

Conjugation

Answer 38

Requires the attachment of two cells and the formation of a bridge that can transport DNA

Question 39

Transformation

Answer 39

The transfer of naked DNA and requires no special vehicle

Question 40

Transduction

Answer 40

DNA transfer mediated through the action of a bacterial virus

Question 41

Fertility or F factor

Answer 41

Only gram negative cells that that operate with a specific plasmid

Question 42

Pilus or sex pilus

Answer 42

Functions in most conjugation transfers

Question 43

Resistance (R) plasmids, or factors

Answer 43

Bear genes for resisting antibiotics and other drugs