Genetics Final
In a heterozygous individual, different alleles are present for a particular gene. What is the genotype of a heterozygous individual for a gene if one allele is dominant and the other is recessive?
Dd
Which type of RNA carries the genetic information from the nucleus to the ribosomes for protein synthesis?
mRNA
Which of the following accurately describes the mRNA molecule after transcription is complete?
Single stranded uracil replacing thymine
During translation, tRNA molecules bring amino acids to the ribosome.
True
For the nonsense variants, which following is correct:
The nucleotide changes turn a coding codon into a stop codon.
A promoter is a sequence where DNA replication is initiated
False
Promoter is a sequence where transcription starts NOT replication initiation
Which one of the following is involved in the process of genomic imprinting?
DNA methylation
What is the term used to describe the specific location of a gene on a chromosome?
Locus
Translation involves which type(s) of RNA(s)
mRNA, rRNA, and tRNA
Ribosomal RNA is directly involved in the formation of peptide bonds during translation.
FALSE
What is the primary role of mRNA in protein synthesis?
Carry genetic information from the DNA to the ribosomes
The start codon that initiates protein synthesis in most cases is:
AUG
Each codon in the genetic code corresponds to a specific
amino acid
Which of the following blood type combinations can never produce a child with blood type O?
AB x A (homozygous)
In X-linked dominate inheritance, affected individual boy or girl inherit the mutant allele from?
Both mom and dad or just mom
Duchenne muscular dystrophy is X-link recessive, what is the risk in the grandsons if their paternal grandfather suffers from Duchenne muscular dystrophy?
0%
What is the likelihood of a son inheriting an X-linked recessive disorder among their children if the mother is a carrier (heterozygous)?
25%
Most traits that exhibit an autosomal recessive pattern of inheritance are the result of what type of mutation?
Loss of function
In autosomal recessive inheritance, an individual must inherit ____ copy/copies of the mutant allele to express the trait or disorder.
TWO
In X-linked recessive inheritance, an affected individual boy inherits a mutant allele from:
The mother only
The presence of an X-linked dominant disease in a male is typically due to:
Inheritance from the mother
A male can inherit an X-linked dominant disorder from his father.
FALSE
Turner syndrome is characterized by which chromosomal abnormality?
A missing X chromosome
In a family with a history of Huntington's disease, what is typically observed regarding the age of onset in subsequent generations?
The age of onset becomes earlier in each generation.
What is the probability that a child will have blood type AB if one parent has blood type A (homozygous) and the other has blood type B (homozygous)?
100%
What type of genetic alteration is most commonly associated with Angelman Syndrome?
Deletion of chromosome 15
Which statement about the O allele in the ABO blood group system is correct?
It is recessive to both A and B.
Which of the following are true about mitochondrial inheritance?
Siblings (including dizygotic twins) have 75% of their alleles in common with their other siblings, but this is only on average.
FALSE, siblings share about 50% of the alleles with their other siblings.
Father carries A/T genotype, Mother carries G/C genotype, what is possible genotypes their children may carry?
A/G, A/C, T/G, T/C
In HWE equation, what does 2pq represent?
The frequency of heterozygous individuals
In a parent-offspring pairs: a child has 50% of alleles in common with each parent at each locus in the human genome?
TRUE
Monozygotic twin shares their 100% alleles, dizygotic twins shares their 50% alleles at any locus.
TRUE
Characteristics of inheritance of complex diseases is a following except:
Tend to be Mendelian inheritance
What is the probability that full siblings DO NOT share any alleles at a given locus?
25%
In a human population of 100 people, the genotype frequencies at one locus are 0.5AA, 0.4Aa, and 0.1aa. What is the frequency of the A allele?
0.70
A autosome recessive inheritance occurred in a village about 1 per 900 in this population. If disease-causing alleles together, we treat them as a single allele with frequency q, then what is the allele frequency of affected individuals and what is the carrier frequency?
0.3, 0.058
Which of the following is NOT typically associated with complex diseases?
Single-gene mutations
Father has A/T genotype, Mother has G/C, what is the possible sharing allele(s) of 1, 2, or 0 between two siblings?
25% for sharing 2 alleles, 50% for sharing 1 allele, 25% for sharing 0 allele
If 16% of a population shows a recessive trait, what is the frequency of the recessive allele q?
0.4
High blood pressure can be considered as which type of trait in a genetic study?
Which term refers to a mutation that alters the DNA sequence but does not change the amino acid specified by a codon?
Silent mutation
A patient with an ultra-rapid metabolizer phenotype for CYP2D6 might require which of the following when taking certain medications?
A higher dose
A fast metabolizer of a medication might require:
A higher dose to achieve the therapeutic effects
Genetic variations that impact drug response are mainly involved in
Drug metabolism and transport
Patients who have a poor metabolism phenotype will have
Slowed metabolism of a drug, leading to accumulation of drug
Which process is also known as programmed cell death?
Apoptosis
Fundamental mechanisms operating in development include cell movement, programmed cell death, gene regulation transcription factors, induction of cell shape and polarity, as well as cell-cell signaling by direct contact and by morphogens
TRUE
Pharmacogenomics is to study of differences between individuals in how people respond to drugs due to their allelic variation genes which affect metabolism, efficacy, and toxicity.
TRUE
A mutation in a codon leads to the substitution of one amino acid with another. What is the name for this type of mutation?
Missense mutation
Cell-cell communication systems are composed of several proteins and molecules. What is the difference between a ligand and a receptor?
Ligand is molecule that binds to receptor
When prescribed medications, individuals who are ultrafast metabolizers based on their cytochrome p450 genotype are at risk of the following?
Underdosing of medications AND most likely no therapeutic effect of medication
Which of the following is TRUE about poor metabolizers?
They may accumulate drugs to toxic levels at standard doses.
A silent mutation is type of mutation that
does NOT change the amino acid sequence
Which of the following describes a haplotype?
A group of alleles that tend to be inherited together
Which factors can contribute to complex inheritance?
Epistasis
Environmental influences
Multiple genes contributing to single trait
Which genotype represents a person with type O blood?
OO
A missense mutation in a gene causes what type of change in the protein?
Substitution of one amino acid for another
Which describes GAIN of function mutation?
It creates a new protein function that wasn't originally present
What does karyotype mean?
A picture of all chromosomes in a cell arranged by size and shape
What type of mutation causes sickle cell?
Missense
Which of the following techniques is commonly used to detect large chromosomal abnormalities?
FISH (fluorescence in situ hybridization)
Which is an example of an environmental factor that could be a teratogen?
Prescription drugs taken during pregnancy
Through what primary mechanism do transcription factors influence development?
Regulating gene expression
Novel environmental agents that cause birth defects are classified as:
Teratogens
Loss of irreplaceable fetal tissue characterized which type of defect?
Disruption
Which category of birth defect results from intrinsic genetic abnormalities?
Malformations
In linkage analysis, a LOD score is used to:
Assess the likelihood that two loci are inherited together by chance
Down syndrome is caused by extra copy of which chromosome
21
Genetic code is read in groups of three called
codons
Which of the following represents the correct order to genetic info flow?
DNA --> mRNA --> protein
What % of their son will be affected among their male offspring if an unaffected father and carrier mother with hemophilia? (X-linked recessive)
50%
If a dominant allele has a frequency of 0.6 in a population, what are the frequencies of recessive and carrier?
0.4 and 0.48
In a pop. of 200 individuals 60 AA, 80 Aa, and 60 aa. What is the frequency of the "A" allele?
0.5
SNPs are most common type of genetic variation and involve:
changes in single DNA base pair
A person with blood type AB can receive blood from which type?
A, B, AB, and O
What is the function of tRNA?
Carries amino acids to the ribosome
Autosomal recessive traits are usually observed in
both males and females equally
What is expected ratio of genotypes of couple who is Aa x Aa?
1:2:1
What is the basic unit of inheritance?
Gene
Punnett square is used to
predict outcomes of genetic cross
Which of the following statements is true for X-linked dominant inheritance?
Affected fathers pass trait to all their daughters
If two carriers of an autosomal recessive genetic disorder have a child together, what is the probability that their child will have disorder?
25%
Sum of all allele frequencies at particular gene locus in a pop. should be equal to?
1
If child inherits B from one parent and O from other, what is their blood type?
B
Autosomal dominant inheritance, parents are heterozygous, what is chance child inherits disorder?
75%
Analysis of pairwise measurements of D' for neighboring variants via genome reveals a complex genetic architecture for LD, thus D' close to 1 is strong LD and close to 0 is weak LD.
TRUE