Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
29 Cards in this Set
- Front
- Back
|
what did the Luria-Delbruck Fluctuation test reveal
|
mutations are not directed at specific genes by selective forces, but rather arise due to random mutation
|
|
|
how do spontaneous mutations arise
|
naturally or randomly due to normal biological or chemical processes in organism
|
|
|
how do induced mutations arise
|
influence from outside source such as radiation, UV light, or natural/synthetic chemicals
|
|
|
what did the Luria-Delbruck fluctuation test
|
how resistance arose in response to T1 bacteriophage
|
|
|
what is the main difference between somatic and germ-cell mutations
|
somatic are NOT inheritable
germ-cell mutations are inheritable |
|
|
what are the 6 types of mutations
|
loss of function
gain of function visible nutritional regulatory behavioral |
|
|
where are the vast majority of mutations most likely to occur
|
on large portions of the genome that do not contain genes
|
|
|
what are polygenic mutations
|
variations at several genes
|
|
|
is polygenic or monogenic mutations more detrimental
|
monogenic mutations are worse b/c they are so specific to the large human genome
|
|
|
for B-Thalassemia disease:
1. what type of disorder is it 2. is it polygenic or monogenic |
1. autosomal recessive blood disorder
2. polygenic |
|
|
For sickle cell anemia:
1. what type of mutation is it 2. what is the specific mutation in the genome 3. what are the symptoms |
1. autosomal recessive genetic disease
2. converts glutamic acid to valine (monogenic) 3. crises (painful episodes that affect the back bones and the long bones of the chest) |
|
|
what are trinucleotime repeat diseases
-main type we learned |
mutant genes that contain trinucleotide repeats
-Huntington's Disease |
|
|
In Huntington's Disease:
1. what type of mutation is it 2. what is the specific mutation in the genome 3. what are symptoms |
1. autosomal dominant genetic disease
2. more than 36 glutamic residues at HTT gene; the repeat is the mutation (normal is 5 to 35 repeats) 3. progressive degenerative disease, symptoms show up later in life |
|
|
what occurs in a tautomeric shift
-does shift occur |
single nucleotide changes within purines or pyrimidines (A to G; C to T)
-no shift |
|
|
In spontaneous mutations, what are the 2 forms of DNA base damage
|
depurination
deamination |
|
|
describe depurination
|
loss of one nitrogenous base in double helical structure
-DNA poly will add random nucleotide during replication |
|
|
describe deamination
|
C changes to U
-causes shift from CG to UT OR A changes to H (H binds with G) -causes shift from AT to CG |
|
|
what are 4 ways that induced mutations can arise
|
mutagens
base analogs intercalating agents adduct-forming agents |
|
|
what are the 6 types of mutagens
|
fungal toxins
cosmic rays ultraviolet light industrial pollutant medical x ray chemicals in tobacco |
|
|
describe what base analogs do
-name a type of base analog |
substitute for purines or pyrimidines during replication (causes increase in tautomeric shift)
-mutagenic chemical |
|
|
what do intercalating agents do
-what types of mutations do they cause |
wedge between DNA base pairs, causing base pair distortions and DNA unwinding
-causes frameshift mutations |
|
|
what do adduct-forming agents do
|
bind to DNA and alter its conformation, interfering with replication and repair
|
|
|
what does UV radiation cause
|
pyrimidine dimers to form (2 identical pyrimidines fused together)
|
|
|
what is the main function of DNA repair systems
|
to maintain the integrity of genetic material that is susceptible to spontaneous or induced mutations
|
|
|
when does mismatch repair become active
|
when proofreading fails
|
|
|
what is the purpose of the Ames test
|
to determine if a chemical is mutagenic
|
|
|
what can sometimes happen to chemicals as they pass through the liver
|
they become mutagenic
|
|
|
during Ames test, how do you know if chemical being tested is mutagenic
|
if his- is reverted back to wildtype his+ prototroph
|
|
|
what are meant by the words transition and transversion
|
refers to mutational nucleotide substitutions
|
