How Cellular Information is Altered

Question 1

What is a selectable mutation?

Answer 1

A selectable mutation confers an advantage for growth, survival, or detection under specific environmental conditions that the wild type does not have.

Question 2

What is expression in the context of genetics?

Answer 2

Expression usually refers to transcription, translation, and post-translation processing.

Question 3

What are mutagens?

Answer 3

Mutagens are agents that increase mutation rates, including chemicals and radiation.

Question 4

What is the significance of Taq polymerase?

Answer 4

Taq polymerase allows PCR to occur at high temperatures, making it essential for the technique.

Question 5

How does PCR benefit scientists?

Answer 5

PCR allows scientists to extract and analyze bits of microbial DNA from samples without needing to grow whole cells.

Question 6

It is the process of subjecting the cells to stress causing changes in the genetic
make-up.

Answer 6

Mutation

Question 7

It is the purposeful transfer of DNA from one type of organism to another.

Answer 7

Genetic Engineering

Question 8

These are mistakes in the genetic code which can arise from replication and/or damage)

Answer 8

Mutations

Question 9

Organism with a genetic mutation

Answer 9

Mutant

Question 10

The organism without the genetic

Answer 10

Wild Type

Question 11

The genetic construction of an organism

Answer 11

Genotype

Question 12

These are characteristics expressed by an organism

Answer 12

Phenotype

Question 13

Examples under Mutation and Selection

Answer 13

➢ Strain A has the tol operon for toluene degradation, and
is in a reactor growing on glucose.

➢ Strain B has the tol operon for toluene degradation, and
is in a reactor growing on toluene.

➢ These strains have the same genotype, but different
phenotypes.

Question 14

Point Mutation: Single Base Change

Answer 14

Consequences: Base change may or may not result in an amino acid change.

Question 15

Consequences for Point Mutation

Answer 15

➢ If the amino acid is different, but not in the region of the
active site, there may be no consequences.

➢ If the mutation is in the active site, there may be some
enzyme activity consequence.

➢ If the mutation changes the amino acid to a stop codon,
the resulting protein will be truncated and probably not
active.

Question 16

Examples of Selectable Mutation

Answer 16

➢ Antibiotic resistance.
➢ Ability to grow on toluene.
➢ Inability to produce lysine.
➢ Ability to produce bioluminescence.
➢ Ability to produce more of an enzyme.
➢ Inability to grow at higher temperatures.

Question 17

Natural Mutation Rates

Answer 17

10^−3 − 10^−9 mutations per cell conversion

10^−6 =
1 mutation/1,000,000 divisions

Question 18

Mutagens results to lots of growth (i.e. lots of division)

Answer 18

➢ Chemicals
➢ Radiation

Question 19

Why do we want to increase mutations?

Answer 19

We want a cell to develop specific characteristics that are
advantages for us.

Question 20

Cite an example of increasing mutations.

Answer 20

Removing feedback inhibition of lysine to increase lysine production

Question 21

UTILIZATION OF MUTATION AND SELECTION

Answer 21

Using mutation and selection, engineers and microbiologists
were able to increase penicillin from 0.001 g/L to 50 g/L.

Question 22

Stages of Natural Gene Transfer/Rearrangement

Answer 22

➢ Transformation
➢ Transduction
➢ Conjugation

Question 23

It is the uptake of free DNA by a cell. The cell membrane has to be permeable to DNA.

Answer 23

Transformation

Question 24

DNA is carried into the cell in a phage.

Answer 24

Transduction

Question 25

In this stage, there is cell to cell transfer of DNA. It is also called mating.

Answer 25

Conjugation

Question 26

Natural Gene Transfer/ Rearrangement

Answer 26

Once the DNA is inside the cell it can remain separate from the chromosome in self-replicating plasmid, or integrate into the chromosome. To integrate, the DNA must be complementary to the chromosomal DNA on the ends.

Question 27

Using natural mechanisms to purposefully manipulate DNA. The DNA is manipulated outside of the cell, and then sent into the cell.

Answer 27

Genetic Engineering

Question 28

Genetic Engineering Tools:

Answer 28

1. Restriction Enzymes 2. Gel Electrophoresis (Southern Blot) 3. Polymerase Chain Reaction (PCR) 4. Plasmid

Question 29

These are enzymes that cut DNA at specific sequences. Different enzymes will cut at different sequences.

Answer 29

Restriction Enzymes

Question 30

A method to detect what sizes of DNA a sample contains.

Answer 30

Gel Electrophoresis

Question 31

A process used to make many copies of a piece of DNA.

Answer 31

Polymerase Chain Reaction (PCR)

Question 32

Self-replicating, circular piece of DNA that can survive in a cell.

Answer 32

Plasmid

Question 33

It allows scientists to extract and analyze bits of microbial DNA from samples, meaning they don't need to find and grow whole cells.

Answer 33

POLYMERASE CHAIN REACTION (PCR)

Question 34

It is an essential element in DNA fingerprinting and in the sequencing of genes and entire genomes.

Answer 34

PCR

Question 35

A technique to photocopy pieces of DNA. A single DNA sequence can be amplified into millions of copies.

Answer 35

PCR

Question 36

It lets scientists work with samples containing even very small starting amounts of DNA. It makes use of the DNA repair enzyme polymerase.

Answer 36

PCR

Question 37

This enzyme, present in all living things, fixes breaks or mismatched nucleotides in the double-stranded DNA helix. These breaks or mismatches could cause genes to malfunction if left unfixed.

Answer 37

polymerase

Question 38

It uses the intact half of the DNA molecule as a template and attaches the right nucleotides, which circulate constantly in the cell, to the complementary nucleotide at the site of the break.

Answer 38

Polymerase

Question 39

It consists of two strands of nucleotide bases, which are represented as A, G, C, and T.

Answer 39

DNA

Question 40

When was the PCR developed?

Answer 40

1985

Question 41

Not all polymerases are created equal. Many __________________

Answer 41

fall apart in high heat

Question 42

The PCR was developed following the discovery of an unusual heat-loving bacterium called

Answer 42

Thermus aquaticus (in a hot spring in Yellowstone National Park)

Question 43

A polymerase of the bacterium Thermus aquaticus that match and attach nucleotides even in the high heat generated by the successive "photocopying" cycles required during PCR.

Answer 43

Taq

Question 44

This made PCR possible.

Answer 44

Taq

Question 45

How is the Insulin Gene transferred

Answer 45

➢ Plasmids separate from the bacterial chromosome. ➢ Restriction enzymes cut across the two strands leaving loose ends to which cDNA can be attached. ➢ Special linker sequences are added to the human cDNA for it to fit precisely into the loose ends of the opened plasmid DNA ring. ➢The plasmid containing the human gene is now ready to be inserted into a living organism.

Question 46

Cloning the HUman Insulin Gene

Answer 46

The plasmid enters the bacterial cell and reproduces itself. When the bacterial cell divides, the plasmids are shared out between the 2 daughter cells and continue to reproduce. This way, clone of identical cells is formed.