Molecular Genetics

Question 1

What is a mutation called when it makes no change in the genetics?

Answer 1

a “silent” mutation

Question 2

three types of mutations (chromosome wise)

Answer 2

(1) genome mutation
(2) chromosomal mutation
(3) single gene mutation

Question 3

mutation type (1) explanation

Answer 3

genome mutation (often lethal) –> change in chromosome #

Question 4

mutation type (2) explanation (four types)

Answer 4

chromosomal mutation
(A) deletion (segment is removed)
(B) insertion (segment is inserted)
(C) inversion (segment order is flipped, e.g. ABC –> CBA)
(D) translocation (segment from one chromosome is added to another, or two segments are swapped)

Question 5

mutation type (3) explanation + some classifications

Answer 5

single gene mutation
(A) deletion
(B) insertion
(C) point mutation (replacing one or more bases)
CLASSIFICATIONS of these single gene mutations
(1) missense (point mutation changes amino acid coding)
(2) nonsense (point mutation creates a new stop signal)
(3) frameshift (insertion or deletion changes reading frame)

Question 6

operon definition

Answer 6

gene segment plus the regulatory pieces (promoter and operator)

Question 7

operator definition

Answer 7

receives the repressor or inactivated repressor that controls the production of certain proteins

Question 8

two types of genes (has to do with operons and stuff)

Answer 8

inducible and repressible

Question 9

What type of pathogen is a virus? (plus definition)

Answer 9

obligate pathogen (must infect other cells to reproduce)

Question 10

virus genetic material + missing organelle

Answer 10

RNA or DNA, not enough to reproduce PLUS there is not ribosome

Question 11

two virus reproduction cycles

Answer 11

(1) lytic cycle: makes virus babies directly (EXPLOSION of little viruses)
(2) lysogenic cycle: injects genes into host for low and slow transcription, translation, and reproduction (incorporating genes, then producing viruses through regular process)

Question 12

five bio technology strategies

Answer 12

(1) Polymerase Chain Reaction
(2) Restriction enzymes
(3) Gel electrophoresis
(4) Gene splicing
(5) Reverse transcription

Question 13

PCR (What? How?)

Answer 13

Polymerase Chain Reaction
What? makes many copies of a target DNA sequence using 3 simple steps
How?
1. Denaturation, unzipping into two complementary strands
2. Annealing, attaching two primers to target sections of the two unzipped strands
3. Extension, taq polymerase makes complementary strands at primers in 5’ direction

Question 14

Restriction enzymes (What? How?)

Answer 14

What?
enzymes that cut DNA so that new DNA can be inserted
How?
cut DNA at palindromic sequences (e.g. AT, GAATTC)
either blunt or sticky
Sticky ends allow DNA to stick together.

Question 15

Gel electrophoresis (What? How?)

Answer 15

What?
process that can separate and allow analysis of DNA sequences
How?
runs DNA fragments through agarose gel using negative charge; larger fragments move slower

Question 16

Reverse transcription (What? How?)

Answer 16

What?
transcribes mRNA, then makes cDNA (complementary DNA) w/o introns
How?
self-explanatory (DUH!)
More efficient!

Question 17

Gene splicing (What? How?)

Answer 17

What?
uses restriction enzymes to insert new DNA segments into plasmids
This can transfer genes from one organism to another.
How?
Restriction enzymes cut target sequence out. Cut plasmid. Insert!

Question 18

Gene splicing results in… (2 things)

Answer 18

transgenic organisms! (genetically modified organisms)

These organisms have recombinant DNA.

Question 19

Three Ways to Get DNA Into Prokaryotes

Answer 19

(1) Conjugation (insert plasmid, a type of vector, with DNA)
(2) Transformation (suck up some DNA from outside environment)
(3) Transduction (have a phage inject it!)