Molecular Mechanisms Flashcards
(34 cards)
Novel property mutations definition
Mutation that confers a novel property on the protein without necessarily altering its normal functions
Sickle cell disease affects the ____ of hemoglobin
Structure
Sickle cell disease illustrates molecular mechanism of a ____ ____ mutation
novel property
Why is sickle cell disease considered a novel property mutation?
Change in the amino acid sequence causes pathology by conferring a novel property on the protein without necessarily altering its normal function
Population genetics is the study of the distribution of ______ in populations
and of how the frequencies of alleles and genotypes are maintained or changed
- alleles
Genetic drift is defined as fluctuations in the _______ of alleles resulting from chance occurrences operating in small populations
-frequency
Founder effects is defined as the [random/nonrandom] distribution of alleles among the individuals who founded particular subpopulations
-nonrandom
In what kind of conditions will you use Hardy-Weinberg approximation?
Autosomal recessive, rare diseases
In the approximation method, how do you determine q?
Take the square root of prevalence
In the approximation method, p is about equal to __
1
The _______ frequency is about twice the minor allele frequency, which is twice the square root of the prevalence
carrier; 2q
In Hardy-Weinberg equilibrium, what are the assumptions that are made?
- Large population
- Random mating
- No selective pressures
- No immigration of different alleles
- No mutations
Stratification
Population that contains a number of subgroups that have remained genetically separate during modern times
Ex: African Americans mating with other African Americans and not Caucasians
Assortative mating
Choice of a mate because the mate possesses some particular trait
Ex: deaf person mating with another deaf person
Consanguinity
Mating with someone who is related by descent
What are some exceptions to a constant allele frequency?
- Selection for or against alleles
- Mutations
- Migration
Which genotype of sickle cell disease confers resistance to malaria and results in a higher fitness than the other alleles?
Sickle cell trait (SC); reproduction is at a higher rate
Thalassemias illustrate the molecular mechanisms of ___ _ ____ and gene dosage effects
- loss of function
What is the genetic inheritance pattern of thalassemias?
Autosomal recessive
Most common forms of alpha thalassemia are the result of ______
deletions
Over 200 mutations are described to cause B thalassemias, this is an example of [allelic/locus] heterogeneity
- Allelic
In B thalassemias, the mutations that occur are mostly missense, nonsense, and ______ mutations
-frameshift
Hereditary persistence of fetal hemoglobin occurs due to _____ mutations in the promoter region of the γ globin genes
- point
Hereditary persistence of fetal hemoglobin illustrates _______ or ectopic gene expression
- heterochronic (Inappropriate expression of a gene at an abnormal time or place)
