Chapter 14

Question 1

forward genetic analysis

Answer 1

mutant phenotype, mutant allele, dna sequence, protein sequence.

Question 2

reverse genetics

Answer 2

protein sequence, dna sequence, mutant allele, mutant phenotype.

Question 3

wild type flies could not

Answer 3

remember to associate odor with shock.

Question 4

creb

Answer 4

activates or represses genes in response to cAMP signaling.

Question 5

choosing an organism for biological study

Answer 5

Generation time, offspring size, genome size

Question 6

ems chemical (common mutagens)

Answer 6

G–>A and C–>T substitutions, transitions, high. loss of function. creates cryptic splice site

Question 7

radiation (common mutagens)
x rays
gamma rays

Answer 7

rearrangements (deletions, inversions), moderate. loss or gain of function.

Question 8

insertional (common mutagens)

transposons

Answer 8

insertions, low. loss of function.

Question 9

dominant mutations

Answer 9

rare, gain of function

1. mutagenize sperm cells
2. mate w wild type female
3. dominant mutations in 1:1 ratio

Question 10

recessive mutations

Answer 10

don’t appear in f1, so more breeding. (F3). loss of function.

1. mutagenize sperm cells
2. mate w wild type female
3. isolate F1 and mate individually to wild type to produce F2.
4. do same thing with F2 to produce F3.
5. identify recessive mutations in F3.

Question 11

balancer chromosomes

Answer 11

used to identify mutations on specific chromosomes. have inversions to prevent recombination. used to study lethal mutations.

Question 12

permissive condition

Answer 12

environment where lethal mutant can survive/grow and produce wild type phenotypes.

Question 13

enhancer screen

Answer 13

modifier screen where second site mutations enhance the phenotype of the initial mutant.

Question 14

suppressor screen

Answer 14

modifier screen where second site mutations suppress the phenotype of the initial mutant.

Question 15

synthetic lethality

Answer 15

two single mutants are viable but the double mutant is inviable.
ex. pn and K-pn double mutant-lethal.
pn and K-pn mutants alone are viable.

Question 16

genetic redundancy

Answer 16

ex of when two genes act in parallel.

loss of function of one gene is compensated by the activity of the other nonmutant gene.

Question 17

transgene

Answer 17

gene modified in vitro by recombinant dna tech and introduced into genome by transformation

Question 18

transgenic organism

Answer 18

an organism with a transgene

Question 19

genomic library

Answer 19

set of clones w dna representing genome of an organism

Question 20

cloning vector

Answer 20

dna from plasmid or virus used to carry foreign genetic material into another cell, where it’s replicated or expressed

Question 21

complementary libraries (cDNA libraries)

Answer 21

dna clones. reverse transcription of mRNA into DNA and cloned into vector.

Question 22

how can genes be identified?

Answer 22

1. by introducing a wild type copy of gene to complement recessive mutant.
2. dna sequencing technology

Question 23

germ line mutation (more common than somatic)

Answer 23

after sexual reprod, 1/2 mutations are passed on to next gen.

Question 24

if you have gain of function in eyeless

Answer 24

extra eyes (ectopic eyes)

Question 25

loss of function eyeless

Answer 25

lack eyes

Question 26

nonsense mutation

Answer 26

null allele

Question 27

hypomorphic allele

Answer 27

loss of function, but depending on protein can also be gain

Question 28

polymorphism can

Answer 28

kill genome mapping

Question 29

which mutation is the best in identifying the muatation in a non saturating screen?

Answer 29

transposons.

Question 30

CRISPR

Answer 30

clustered regularly interspaced palindromic repeats. acts as defense mechanism against invading nucleic acids.

Question 31

cas genes

Answer 31

dna endonuclease, either single protein or protein complex

Question 32

crispr repeats act as

Answer 32

guides to direct cas to a specific sequence of an invading phage

Question 33

crRNA

Answer 33

from CRISPR w repeat/unique sequence. binds to tracrRNA and cas. target specificity.

Question 34

tracrRNA

Answer 34

binds to cas to form RNA-protein

Question 35

single guide RNA

Answer 35

tracrRNA + crRNA

Question 36

any 20 bp sequence has probability of occurring at random approximately once every

Answer 36

10^12 base pairs

Question 37

knockout libraries

Answer 37

collection of mutants where all genes have been mutated by knocking out expression. inserting exogenous pieces of dna.

Question 38

if dna has no origin of replication

Answer 38

undergo enzymatic degradation or integration into host genome.

Question 39

illegitimate recombination

Answer 39

exchange of genetic info bw non homologous dna molecules.

Question 40

homologous recombination

Answer 40

exchange of genetic info bw homologous dna molecules.

Question 41

in a single crossover circular dna

Answer 41

integrated into yeast genome, without replacement of target gene

Question 42

in a double crossover circular dna

Answer 42

replaced with the introduced dna. replacement of target gene.

Question 43

gene knockout

Answer 43

creates recessive loss of function allele

Question 44

study loss of function gene through

Answer 44

injecting RNAi

Question 45

how to detect crispr-cas (hard part)

Answer 45

find the mutation in the animals. in the germ line so they pass it on.this is by injecting crispr-cas9. through heteroduplexes (one wild type, one mutant). •high resolution melt (denaturing temps) •sequencing pcr

Question 46

glowing green animal (reporter gene)

Answer 46

it has a trans gene. •transcriptional fusion GFP •translational fusion GFP + GoI gene of interest

Question 47

enhancer trapping

Answer 47

uses variation of insertional library to identify genes based on expressional patterns

Question 48

lacZ type of reporter gene

Answer 48

in vitro. outside organism

Question 49

GUS type of reporter gene

Answer 49

not in vitro. cant monitor while its living. disadvantage. for plants.