Exam 2 - Chapter 8

Question 1

Mutation

Answer 1

Changes the existing nucleotide sequence of a cell’s DNA

Question 2

Vertical Gene Transfer

Answer 2

The passing down of mutations to the progeny (daughter cells)

Question 3

Progeny

Answer 3

Daughter cells

Question 4

Horizontal Gene Transfer

Answer 4

The movement of DNA from one organism to another

Question 5

Auxotroph

Answer 5

A mutant that requires a growth factor (auxo means increase)

Question 6

Prototroph

Answer 6

A mutant that does not require a growth factor (proto means earliest form of)

Question 7

Wild Type

Answer 7

The typical phenotype of strains isolated from nature

Question 8

Reversion

Answer 8

When a mutation changes back to its original, non-mutated form

Question 9

Base Substitution

Answer 9

When an incorrect nucleotide sequence is incorporated. Three kinds: Silent, Missense, and Nonsense

Question 10

Point Mutation

Answer 10

When only one base pair is changed

Question 11

Silent Mutation

Answer 11

A base change occurs, but the new codon still codes for the same amino acid as the wild type

Question 12

Missense Mutation

Answer 12

The new codon codes for a different amino acid. Most cases the protein only functions partially

Question 13

Nonsense Mutation

Answer 13

The new codon is a stop codon, making a shorter and usually non functioning protein

Question 14

Knockout Mutation

Answer 14

Totally inactivates the gene

Question 15

Frameshift Mutation

Answer 15

When one or two nucleotides are ADDED. Usually results in a knockout mutation

Question 16

Transposons (Jumping Genes)

Answer 16

Mutagens that are pieces of DNA that can move from one location to another in a cell’s genome, by transposition, inactivating the genes

Question 17

Induced Mutation

Answer 17

Genetic changes that occur due to an influence outside the cell, such as radiation

Question 18

Direct Selection

Answer 18

The mutant will grow but the parent won’t

Question 19

Indirect Selection

Answer 19

Is used to isolate an auxotrophic mutant from a prototrophic parent. Both the parent and mutant can grow in certain mediums

Question 20

Replica Plating

Answer 20

This is for isolating auxotrophic mutants in indirect selection. You get one medium for both the mutant and parent to grow in. Then you get a nutrient plate and a bs plate and transfer the medium to both of these “replica plates” the parent will grow in both but the mutant will only grow in the nutrient plate

Question 21

Recombinants

Answer 21

A recipient of horizontal gene transfer. These genes have new characteristics and copies of the original strains

Question 22

DNA-mediated Transformation

Answer 22

“Naked” DNA is taken up from the environment by a bacterial cell

Question 23

Transduction

Answer 23

DNA is transferred from one bacterial cell to another by a bacteriophage (a virus that infects bacteria)

Question 24

Conjugation

Answer 24

DNA is transferred during cell to cell contact. Plasmid transfer is one kind, chromosome transfer is another but only Hfr cells can be donors

Question 25

Conjugative Plasmids

Answer 25

Direct their own transfer from donor to recipient cells

Question 26

Core Genome

Answer 26

The genes that are in the entire gene pool of a species

Question 27

Mobilome (Mobile Gene Pool)

Answer 27

The genes that can be transferred

Question 28

Plasmids

Answer 28

Circular double-stranded DNA replicon; generally code only for non-essential genetic information

Question 29

R Plasmids (Resistance Plasmids)

Answer 29

Develop resistance to medications. Consist of Resistant gene and Resistance Transfer Factor (RTF), used for transferring the R genes via conjugation

Question 30

Base Analogs

Answer 30

Structurally resemble nucleobases but have different hydrogen-bonding properties

Question 31

Intercalating Agents

Answer 31

Insert between adjacent base pairs during replication, either adding or deleting a base pair, resulting in a frameshift mutation

Question 32

Mismatch Repair

Answer 32

Used to repair errors by breaking off the section with the error, which is then redone by DNA ligase and polymerase

Question 33

Photoreactivation (Light Repair)

Answer 33

Enzyme uses energy from visible light to break apart the thymine dimers caused by UV radiation

Question 34

Excision Repair (Dark Repair)

Answer 34

Similar to mismatch repair, the bacteria recognizes where the thymine dimer is, and breaks this segment off. DNA ligase and polymerase then seal it

Question 35

SOS Repair

Answer 35

Last resort to fix thymine dimer