Unit 1 Flashcards
Genome
All the genetic information in an organism
Chromosome
Discrete structures that package an organisms genome
Genetics
The study of genes
Gene
Basic unit of heredity that controls a trait
Traits
Characteristics that can be observed or measured
Complex trait
Trait that is controlled by more thatn one gene
Pleiotropic Gene
One gene that controls multiple traits
The following are features of prokaryotic cells except A. Single-stranded DNA genome B. No nucleus C. Cell wall D. One circular chromosome
A. Single-stranded DNA genome
Which of the following traits is the result of a pleiotropic allele?
A. Height
B. Intelligence
C. Eye color
D. Sickle cell anemia
D. Sickle cell anemia
Which of the following would NOT describe the genotype of someone with Huntington’s disease?
A. Heterozygous
B. Hh
C. Wildtype
D. Autosomal dominant
C. Wildtype
If an organism has 40 autosomes and 1 sex chromosome and it is diploid, how many total chromosomes does it have?
82
Organisms such as humans are _______ because they contain two copies of the genome.
Diploid
Select all that are correct. Homologous chromosomes, 1 from male parent: 1 from female parent, have the same:
o Alleles
o Gene organization
o Centromere position
o Overall size
- Gene organization
- Centromere position
- Overall size
Which of the following describes an allele that contains mutations to inactivate the gene product?
A. Wildtype
B. Dominant
C. Gain-of-function
D. Loss-of-function
D. Loss-of-function
Which of the following is NOT one of the reasons why Mendel’s choice of pea plants was a great model system for understanding genetics?
A. Traits were controlled by more than one gene
B. Mating (genetic crosses) can be controlled in pea plants
C. Genes responsible for the different traits were not complicated by linkage
D. Many homozygous, true-breeding varieties were available
A. Traits were controlled by more than one gene
Mendel discovered the Law of Segregation through his pea plant experiments. This allowed us to understand that:
A. The elementon is blended during transmission
B. Alleles of one gene separate into different gametes during meiosis
C. Alleles of two different genes independently assort during meiosis
D. Each trait is controlled by multiple alleles
B. Alleles of one gene separate into different gametes during meiosis
Mendel’s work was largely unappreciated until the early 1900s when meiosis had been observed. Meiosis provided a physical explanation for Mendel’s laws. During which phase of Meiosis is the Law of Independent Assortment apparent?
A. Metaphase II
B. Mitosis I
C. Metaphase I
D. Meiosis II
C. Metaphase I
If two genes are linked, this means that:
A. All of these are true of linked genes
B. They are found “close” together on a chromosome
C. They do not obey Mendel’s Law of Independent Assortment
D. They are less likely to recombine during meiosis
A. All of these are true of linked genes
Genetics experiments are sometimes carried out by making mutants and then mapping the position of allele that is responsible for the phenotype. This is called _______ genetics.
Forward
When a geneticist begins by looking at the sequenced genome to identify genes and characterize the phenotypes that result from making mutations, this is called _________ genetics.
Reverse
What are the purines?
Adenine and Guanine
Contain a two-ringed structure
(shorter word, bigger structure)
What are the pyrimidines?
Cytosine Thymine
single-ringed structure
*longer word, smaller structure
Transition mutation
Replaces a purine with a purine
OR
Pyrimidine with a pyrimidine
Transversion mutation
Purine with pyrimidine
OR
Pyrimidine with purine
Insertion mutation
Addition of one or more bases
Complementation Test
Test to determine if various mutations are found on the same or different genes.
The difference between ribose and deoxyribose is:
A. The 2’ C-OH is found in ribose only
B. Deoxyribose is a hexose sugar
C. 3’ C-OH iis found in deoxyribose only
D. 1’ C is the attachment site for nitrogenous bases in DNA only
A. The 2’ C-OH is found in ribose only
Which of the following is NOT a nucleoside? A. Adenosine B. Guanosine C. Cytosine D. Uridine
C. Cytosine
Which of the following are true about alleles? Mark all that are true.
- Dominant alleles are always gain-of-function
- A gene can have hundreds of different alleles, but diploid organisms can only have 2 alleles
- Recessive alleles are always loss-of-function
- Wildtype alleles are always dominant because they produce a functional product
- Males are hemizygous for x-linked alleles
- A gene can have hundreds of different alleles, but diploid organisms can only have 2 alleles
- Recessive alleles are always loss-of-function
- Males are hemizygous for x-linked alleles
The enzyme responsible for relieving supercoiling ahead of the replicaiton fork is:
Topoisomerase
Why would the enzyme reverse transcriptase be called an RNA-dependent DNA polymerase?
A. It uses a DNA template to replicate
B. It uses an RNA template to synthesize DNA
C. It uses a DNA intermediate for transcription.
D. It uses a DNA template to synthesize an RNA molecule
B. It uses an RNA template to synthesize DNA
In B DNA, what would be the length of 2 turns of the double helix? A. 34 Angstroms = 3.4 nm B. 68 Angstroms = 6.8 nm C. How could we possibly know that?! D. 1 Angstrom = 0.1 nm
B. 68 Angstroms = 6.8 nm
True or False: Nucleotides are ALWAYS synthesized from a free 3’ OH, referring to the 3’ Carbon on the pentose sugar.
True
Which of the following is the correct name for a nucleotide (nucleoside triphosphate)? A. Cyotosine triphosphate B. Thymidine triphosphate C. Uracil triphosphate D. Deoxyadenine triphosphate
B. Thymidine triphosphate
What must we account for in the revised Central Dogma?
A. DNA undergoes replication
B. RNA is translated into protein
C. RNA can be reverse transcribed into DNA in some viruses
D. DNA is transcribed into an intermediate
C. RNA can be reverse transcribed into DNA in some viruses
Why is it inaccurate to define a gene as “one gene encodes one polypeptide”?
A. One gene encodes multiple primary transcripts
B. Genes can code for RNA that is not translated
C. Proteins are often made up of more than one polypeptide
D. Multiple genes code for one polypeptide
B. Genes can code for RNA that is not translated
In the complementation test, crossing two homozygous recessive individuals with similar phenotypes to yield all mutant offspring means that:
A. The two parents’ mutations are in the same gene
B. The two parents carry mutations in different genes
C. The two parents carry mutations in different nucleotides in the same gene
D. The two parents carry the same mutation in the same nucleotide.
A. The two parents’ mutations are in the same gene
Because of DNA sequencing, it is possible to scan dsDNA sequences for regions that potentially encode polypeptides, or ORFs. Which of the following is NOT true of these analyses?
A. There can only be one true ORF in a sequence of DNA
B. There are 3 reading frames per strand of DNA
C. ORFs contain a start and a stop codon
D. ORFs often contain 100s to 1000s of continuous amino acids
E. Reading frames must be read from 5’ to 3’
A. There can only be one true ORF in a sequence of DNA
Which of the following is an example of a transversion mutation? A. TA --> CG B. TA --> UA C. AT --> GC D. AT --> CG
D. AT –> CG
Mark all of the following that are TRUE of the ABO blood groups.
- The O allele is considered wildtype becuase it is the most common in the population
- The ABO gene encodes a transferase protein
- The O allele is loss-of-function because it does not produce transferase
- The A and B groups are considered wildtype because they produce a functional protein.
- The ABO gene encodes a transferase protein
- The O allele is loss-of-function because it does not produce transferase
Once a mutation has occurred in a particular gene, which of the following can NOT reverse the effects of the mutation? A. True reversion B. Second-site reversion C. Back mutation D. Hypomorphic mutation E. Suppressor mutation
D. Hypomorphic mutation
Which of the following is true of pyrimidines and/ purines? A. C and G are purines B. Purines have one ring structure C. C, T, and U are pyrimidines D. Pyrimidines have a two ring structure
C. C, T, and U are pyrimidines
The message strand contains: (check all that apply)
- A, G, U, and C nucleotides
- the template for making RNA transcript
- the sequence that RNA polymerase transcribes
- The identical sequence to the primary transcript except it has Ts
-The identical sequence to the primary transcript except it has Ts
Which of the following is NOT true?
A. Flies, humans, and worms have intron sizes that are very similar
B. Most exons correspond to the length of a protein domain (30-60 amino acids)
C. GC content tends to be higher in exons than introns
D. Exons are not joined from two separate alleles
E. Exons are maintained in the same order as they are found in the gene
A. Flies, humans, and worms have intron sizes that are very similar
The introns early hypothesis (check all that apply):
- Is supported by the fact that genes appear to be fused in bacteria to make one polypeptide
- Explains that genes have always been interrupted but smaller genomes have evolved ways of eliminating introns
- Poses that genes originated as uninterrupted
- Is supported by evidence that mobile elements can act like introns.
- Is supported by the fact that genes appear to be fused in bacteria to make one polypeptide
- Explains that genes have always been interrupted but smaller genomes have evolved ways of eliminating introns
Exome
All the exons of a genome
Transcriptome
all the RNA molecules expressed in a tissue and/or at a given time
Proteome
Complete set of proteins within a cell
Interactome
All the protein-protein complexes and interactions within a cell
Epigenome
All of the packaging tags on chromatin
Which type of polymorphism is used for identification of suspects in CoDIS?
A. Repetitive DNA Sequences
B. Short Tandem Repeats
C. Restriction Fragment Length Polymorphism
D. Single Nucleotide Polymorphism
B. Short Tandem Repeats
Which type of polymorphism is found every 1 kb in the human genome and makes finding disease-causing alleles faster?
A. Short Tandem Repeats
B. Moderately Repetitive DNA
C. Restriction Fragment Length Polymorphism
D. Single Nucleotide Polymorphism
D. Single Nucleotide Polymorphism
Larger genomes within a phylum contain more: A. Exons B. Introns C. repetitive DNA from transposons D. genes
C. repetitive DNA from transposons
Which of the following is NOT true of mtDNA and mitochondria?
A. mtDNA is circular and found in multiple copies per organelle
B. Mitochondria evolved by endosymbiosis
C. mtDNA tends to have more kb in plants than animals
D. Not all of the proteins needed are synthesized in the mitochondria; some are encoded by the nuclear genome
E. mtDNA codes for Rubisco and other enzymes needed by the organelle
E. mtDNA codes for Rubisco and other enzymes needed by the organelle
True or False: A major difference between ctDNA and mtDNA is that ctDNA is larger than mtDNA, and animals do not have ctDNA.
True
Which of the following is NOT true of polymorphisms and disease?
A. For a polymorphism to be identified, it must exist in at least 1% if the population
B. Polymorphisms must be located in a disease-causing allele to be linked to a disease
C. SNPs are used for genotyping such as by 23andMe
D. An individual can be heterozygous or homozygous for a polymorphism even if it is outside of the transcription unit.
B. Polymorphisms must be located in a disease-causing allele to be linked to a disease
What is a major difference between whole genome sequencing and genotyping?
A. Genotyping is more expensive than whole genome sequencing
B. Genotyping provides deterministic information about traits and diseases
C. Genotyping involves sequencing a portion of the genome called the exome
D. Genotyping is limited to less thatn 0.5% of the genome
D. Genotyping is limited to less thatn 0.5% of the genome
Which of the following genes has mutant alleles that are deterministic for acquiring Alzheimer’s disease? (Check all that apply)
- CFTR
- APP
- PS-2
- APOE
- PS-1
- APP
- PS-2
- PS-1
(APOE is not deterministic)
Which of the following is an "actionable" gene? A. Htt B. Notch C. APP D. BRCA1 E. CFTR
D. BRCA1
For which allele does the drug Kalydeco improve the disease symptoms if it is used early in the person's diagnosis? A. CFTR^G351D B. APOe4 C. BRCA1 D. CFTR^F508 E. APOe2
A. CFTR^G351D
