Genetics Midterm
Endorphins
"morphine within"--natural, opiatelike neurotransmitters linked to pain control and to pleasure.
Cliff has colorblindness and ichthyosis, which causes scaly skin. Both traits are X-linked recessive. The probability that he transmits both traits to his sons is
0
Traditional methods of assessing multifactorial studies, such as adoption and twin studies, show a heritability of Blank______ for intelligence.
0.5-0.8
The heritability of schizophrenia is estimated to be Blank______.
0.9
A male individual is heterozygous for a gene for big ears, Bb. After meiosis in a cell from this individual, how many gametes will there be and what will their genotypes be with regard to the B gene?
4 gametes, two with genotype B and two with genotype b
You are working with a novel organism with double stranded DNA and you discover that this organism has 20% adenine in its DNA. What percentage of cytosine do you expect that this organism has in its DNA?
30%
A species has a diploid number of 36. Without meiosis, the gametes would each contain __________ chromosomes, and the fertilized ovum would have __________ chromosomes.
36; 72
Spermatogenesis
4 Gametes are produced that can potentially contribute to zygote a mitochondria-containing midpiece must be present in mature cells An acrosomal region must be present in mature cells
Children with Down syndrome have all or part of a third copy of chromosome 21. Which cause of intellectual disability best describes the cause of Down syndrome?
Abnormal gene and chromosome
Use the terms provided to label the diagram representing the flow of information from DNA to protein.
DNA to protein
Erwin Chargaff
Discovered that DNA composition varies, but the amount of adenine is always the same as thymine and the amount of cytosine is always the same as guanine.
Progerias
Diseases characterized by dramatic and premature aging
Progenroid
Disorders that accelerate aging and shorten life, or that make a person appear older than they are but do not affect lifespan
Select receptors that have been implicated in drug addiction.
Dopamine D(2) receptor Nicotinic receptor
The A1 allele of which receptor gene is associated with alcoholism and other addictions?
Dopamine D(2) receptor gene
Which of the following syndromes displays unusual ridge patterns in the affected individuals?
Down syndrome
Which of the following are the best studied genetic causes of intellectual disability?
Down syndrome Fragile X syndrome
Laron syndrome
Dwarfism caused by defected GH-receptors ↓linar growth ↑GH ↓IGF-1 Short stature, small head, saddle nose, small genitalia No cancer, diabetes
Imagine that the genes for eyelash length and hair texture are on the same chromosome. A man with long eyelashes and straight hair has one chromosome with the E gene and the S gene, and a second chromosome with the recessive genes, e and s. Assuming crossing over does not occur in meiosis, what combinations of genes should you see in his gametes?
ES,es
case-control study
Each individual in one group is matched to an individual in another group who shares as many characteristics as possible.
Embryonic induction
Embryonic cells produce signals that alter the behavior of neighboring cells.
Select the sources of human stem cells
Embryonic stem cells Induced pluripotent stem cells Adult stem cells
A child starts school, and it is discovered that he has intellectual disabilities. His mother notes that he was post-natally exposed to mercury. What is the likely cause of his intellectual disability?
Environmental exposure to toxins
In schizophrenia, patients experience _________symptoms.
Episodic
Which Austrian-American biochemist showed that DNA in several species contains equal amounts of the bases adenine (A) and thymine (T) and equal amounts of the bases guanine (G) and cytosine (C)?
Erwin Chargaff
What did microbiologists Alfred Hershey and Martha Chase use to show that protein does not transmit genetic information?
Escherichia coli bacteria infected with a virus
The human body cannot synthesize these amino acids Essential 2. The human body can synthesize these amino acids Non-essential 3. The human body can synthesize these amino acids, except for in certain circumstances Conditionally essential
Essential protein , Non-essential, Conditionally essential
Eukaryotic Cells
Eukarya, have a nucleus, have membrane bounded organelles
What is the term that describes the DNA sequences for protein-encoding genes?
Exome
Genetic variants of which gene have been associated with developing PTSD (posttraumatic stress disorder)?
FKBP5
An allele combination that produces a phenotype in everyone who inherits it is not penetrant.
False
proteins involved in drug addictions?
Forming receptors on the postsynaptic neuron that are activated or inactivated when specific neurotransmitters bind Producing neurotransmitters, such as enzymes Removing excess neurotransmitters from the synapse Conveying chemical signals in the postsynaptic neuron
Lithium is a drug used to treat bipolar disorder. If taken during pregnancy, it can cause heart defects. Based on what you've learned about teratogens, when do you predict an embryo or fetus will be sensitive to lithium?
From 0-1.5 months
The term "inborn error of metabolism" is associated with the English physician
Garrod
Which biochemical unit encodes a single protein?
Gene
neural plasticity
Genes affect the number and the pattern of neuronal connections. Constant change in the nervous system structure and function
What do unhealthy habits among some centenarians possibly indicate?
Genes are protecting them.
linked genes
Genes located on the same chromosome that tend to be inherited together in genetic crosses.
Cutis Laxa (Elastolysis)
Golgi
Cutis laxa is a connective tissue disorder. One of the causes is abnormal glycosylation of serum proteins. Glycosylation is the addition of a carbohydrate such as a sugar to another molecule. Which organelle do you predict is affected in cutis laxa?
Golgi apparatus
Which of the following symptoms are seen in people with Rothmund-Thomson syndrome?
Gray hair and osteoporosis
A woman with genotype AG at the site of the period 2 gene that controls waking time marries a man with genotype GG. What time will their children awaken?
Half of them should awaken about a half an hour earlier than the other half.
Symptoms of schizophrenia include delusions and ______________.
Hallucinations
A young girl is born that does not express the XIST gene. What will this mean for the expression of her genes relative to that of her brother?
Her cells will contain 2X the level of proteins encoded by the X chromosome compared to her brother's cells.
Major Depressive Disorder (MDD)
Tiredness, trouble making decisions, concentrating, and recalling details Lack of enjoyment of favorite activities
Griffiths (1928)
Transformed 'R' bacteria into 'S'
the leptin receptor
Treatment with leptin results in weight loss for some people but not for others. Leptin resistance, or unresponsiveness to leptin when it is given as a drug, is due to mutations in the gene that encodes the ________________________. a. leptin receptor b. neuropeptide-Y c. ghrelin d. leptin
A phenotype is variably expressive if symptoms vary in intensity among different people.
True
Werner syndrome is associated with which of the following symptoms?
Type 2 diabetes and atherosclerosis
A variation of the gene MFSD12 is associated with pale skin tones. Dark skin is due to ______ of the gene variant and lighter skin tones are due to _____.
Underexpression; Overexpression
Many gene __________contribute to schizophrenia.
Variants
genetic heterogeneity
When different genes produce the same phenotype, this is called
Development of PTSD (posttraumatic stress disorder) has been associated with Blank______ of the FKBP5 gene.
a change in the methylation pattern specific genetic variants
genomic imprinting.
a phenomenon in which expression of an allele in offspring depends on whether the allele is inherited from the male or female parent
Genetic heterogeneity
a phenotype that can be caused by variants of any of several genes
psychosis
a psychological disorder in which a person loses contact with reality, experiencing irrational ideas and distorted perceptions\ Schizophrenia is a form of psychosis, a disease of thought and sense of self.
Although both male and female sheep carry the genes for horn development, only male sheep grow horns. This is an example of __________.
a sex-limited trait
RNA primers
a short strand of RNA, made by DNA primase, that is used to elongate a strand of DNA during DNA replication
Genetic Modification (GM)
a technology that changes the genetic material of a living organism
sex-influenced.
a trait that is caused by a gene whose expression differs in males and females In cattle, mahogany spots are dominant in males and recessive in females.
Watson and Crick described the relationship between nucleic acids and proteins as a directional flow of information called the Blank______. Multiple choice question.
central dogma
Spindle assembly checkpoint
checks for all chromosomes being attached to the spindle before the cell progresses with mitosis
DNA damage checkpoint
checks for damaged DNA before it enters S phase
If there is a(n) _______ between two characteristics, then if one measurement increases, the other characteristic changes in a predictable direction.
correlation
Diseases that are caused by protein misfolding include
cystic fibrosis and Huntington disease.
Necleotide
deoxyribose sugar, Phosphate group, one nitrogenous base
Watson & Crick (1953)
determined double helix structure of DNA
Rosalind Franklin and research student Raymond Gosling provided a pivotal clue to deducing the three-dimensional structure of DNA by Blank______
developing the image of the structure of B DNA
genetic heterogeneity
different genes can produce identical phenotypes
Oswald Avery, Colin McLeod, and Maclyn McCarty are credited with the Blank______.
discovery that Griffith's "transforming principle" was DNA
What type of structure do purines have?
double ring structure
Unlike schizophrenia, mood disorders are ________-, and dementias are __________.
emotional , cognitive
Phenocopies
environmentally produced phenotypes that mimic conditions caused by genetic mutations
Imprinting disorders illustrate
epigenetics
Changes in allele frequencies in populations is the basis of
evolution
Which of the following is an example of nearly a pure polygenic trait?
eye color
Along with the gene for hypocretin, at least three other genes are associated with insomnia. The most severe condition is Blank______, which is a condition of infectious protein misfolding.
fatal familial insomnia
Progerin
gene encoding for Lamin A which is mutated in hutchinson-gilford progeria
Select the examples of genetics
gene that control eye color linked to a certain disease passed through a family
Prader-Willi and Angelman syndromes both arise from the same area of chromosome 15, illustrating
genomic imprinting.
For a polygenic trait with little or no environmental influence, the concordance value for monozygotic twins will be _______ the concordance value for dizygotic twins.
greater than
A daughter can inherit an X-linked recessive disorder if
her mother is a carrier and her father has the disorder.
Human females are the __________ sex.
homogametic (XX)
ghrelin
hormone secreted by empty stomach; sends "I'm hungry" signals to the brain
A Punnett square is used to track
how alleles combine in offspring.
When a baby with lactase deficiency is given lactose-free infant formula
how knowing the cellular basis of a disease can suggest a treatment for the disease.
The first narcolepsy gene to be discovered was one that encodes a receptor for a neuropeptide called Blank______
hypocretin
It was confirmed that DNA was the material that transformed the bacteria used in Griffith's experiment when Avery, MacLeod, and McCarty observed that transformation was disrupted when cells were Blank______.
treated with deoxyribonuclease
Apoptosis checkpoint
turns on as mitosis begins ,If survivin accumulates, mitosis will occur
Autosomal Recessive
two copies of an abnormal gene must be present in order for the disease or trait to develop
Chromatids are
two identical chromosomes that split and contain the same genetic material
tRNA (transfer RNA)
type of RNA molecule that transfers amino acids to ribosomes during protein synthesis Structural RNA that links an amino acid to an anticodon
Incompletely penetrant
some individuals do not express the phenotype or have no symptoms
To assess the genetic component of a complex trait, it would be most appropriate to
study monozygotic twins separated at birth
The head-to-toe configuration of DNA derives from the structure of the Blank
sugar-phosphate backbone
When analyzing the composition of nucleic acids, biochemist Phoebus Levene discovered that the Blank______ were always the same but the Blank______ were of four types
sugars and phosphates; nitrogen-containing bases
circadian pacemaker
the "master control" for a person's various circadian cycles, consisting of a group of neurons forming the suprachiasmatic nuclei of the hypothalamus
X inactivation is controlled by
the XIST gene
In Frederick Griffith's experiment to identify the genetic material, the mice injected with Type S bacteria developed pneumonia because
the bacteria's capsule protected them from the immune system of the mice
Epistasis
the blocked gene is expressed normally, but the product of the modifier gene inactivates it
Genome
the complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes The entire sequence of an organism's genetic material is its
Expressivity
the degree to which a genotype is expressed in an individual
The Hershey-Chase experiment was designed in such a way that if Blank______, then it could be deduced that DNA is the genetic material.
the infected bacteria had radioactive phosphorus
The calculation for determining sex ratio is
the number of males divided by the number of females multiplied by 1,000 for people of a particular age.
The directionality of a DNA strand is determined by
the numbering system of the sugar
Oogenesis
the production, growth, and maturation of an egg, or ovum transformation of the simple three layers of the embryo into distinct organs
In Griffith's experiment, when a combination of type R and heat-killed type S bacteria were injected into mice, the mice developed pneumonia and died. This was because
the type S bacteria transferred their killing trait to type R bacteria
multiple alleles
three or more forms of a gene that code for a single trait
When a dominant allele of one gene and a recessive allele of a second gene are on the same chromosome, the genes are in the
trans configuration.
Neural plasticity
Ability of the brain to change their experience, both structurally and chemically
Imagine that the genes for long nose hair and buck teeth are on the same chromosome. A man with long nose hair and buck teeth has one chromosome with genes N and b and one chromosome with genes n and B. For each of the four possible combinations below, indicate if the gametes contain a parental or recombinant meiotic product.
1. NB Recombinant product 2. nb Recombinant product 3. nB Parental product 4. Nb Parental product
A population of laboratory mice who share the same environment, for whom variability is completely the result of gene action, exhibit Blank______ heritability for the trait.
1.0
True or False
1.Apoptosis is a form of cell death in which cells are broken down into membrane-enclosed pieces and then digested by phagocytes. True 2. During development, both mitosis and apoptosis help to maintain cell number. True 3. During apoptosis, enzymes called caspases replicate the cell's DNA. False 4. Cells that are undergoing apoptosis are usually flattened in appearance and adhere strongly to neighboring cells. False 5. Cancer may occur when apoptosis happens too frequently. False
The probability that the daughter of a woman with a dominant disease-causing allele on one X chromosome and a normal male will be affected with the disorder is
1/2
Sixteen-year-old Rhapsody has just learned that her younger brother Clyde is colorblind. Although she knows she has color vision because her cat, Juice, is clearly orange, and she reads that nearly all people with colorblindness are boys, she is concerned about her own sons one day. If she is a carrier for colorblindness, then the risk that a son of hers is colorblind is
1/2.
A diploid cell in G1 contains 5 pairs of chromosomes. During mitosis, how many chromosomes will be lined up on the metaphase plate in this cell?
10
Diseases caused by single genes that approach 100 percent penetrance approach 100 percent Correctconcordance in monozygotic twins.
100%
A somatic cell in an organism has 22 chromosomes. How many chromosomes will a germ cell from the same organism have?
11
The oocyte can only be fertilized in the Blank______ after ovulation.
12-24 hours
True or False
2. In biology, a population is a group of individuals that can have healthy offspring together. True 3. Evolution is the change of allele frequencies in a population. True 4. Changes in DNA sequences are the basis of diversity in different species. True 1. The combination of alleles in an individual is the individual's gene pool. False 5. Humans do not share DNA sequences with other mammals. False
Bipolar disorder affects approximately ______ percent of the population.
2.6
Among dizygotic twins, concordance is usually around 25 Correctfor a recessive trait.
25%
An investigator determines that gene c and gene f are linked on chromosome 5 of the honeybee genome. Bees that are homozygous for the dominant wild type alleles have long stingers (c+c+) and bi-lobed wings (f+f+). Bees that are homozygous for the recessive mutant alleles have short stingers (cc) and tri-lobed wings (ff). The parent generation was composed of homozygous dominant male bees (c+c+f+f+), and homozygous recessive females (ccff), which produced a heterozygous F1 generation. Male bees from the F1 generation (c+cf+f) were mated in a testcross with homozygous recessive females (ccff). The testcross produced the F2 generation. The resulting phenotypic ratios in the F2 generation were as follows: Long stingers and bi-lobed wings (362); short stingers and tri-lobed wings (348); long stingers and tri-lobed wings (151); and short stingers and bi-lobed wings (139). Based on the recombination frequency of this cross,
29 map units
Initiation, elongation, and termination
3 stages of transcription
What is the complementary DNA strand to the following strand: 5' - AGGCGGATCGACCGTAC - 3'?
3' - TCCGCCTAGCTGGCATG - 5'
You are working with a novel organism with double stranded DNA and you discover that this organism has 20% adenine in its DNA. What percentage of cytosine do you expect that this organism has in its DNA? ____%
30
1. If a trait is determined entirely by genes, not by the environment, then the heritability of the trait is 0. False 3. The heritability of a single-gene trait is always 1.0 False 5. If the heritability of a trait is very high, then all siblings will have the same phenotype. False 6. Genetic variance for a polygenic trait is due mainly to the additive effects of dominant alleles of different genes. False
4. The heritability of a trait changes when the environment changes. True 2. Heritability is defined as the proportion of the phenotypic variance for a trait that is due to genetic differences in a population at a certain time. True
Some inherited disorders (such as Down syndrome) are associated with unusual fingerprint ridge patterns. ( genes ) 2. Fingerprint patterns are altered when a fetus touches fingers and toes to the walls of the amniotic sac. ( environment ) 3. Height is affected by diet. ( environment) 4. Certain patterns of SNPs are common in individuals who experience a period of rapid height increase. (genes) 6. Exercise decreases the risk of heart disease. (environment ) 7. Exposure to the sun increases melanin synthesis. (environment )
5. A certain allele of the E4 gene, which encodes apolipoprotein E, increases the risk of a heart attack in people who smoke but not in people who do not smoke. both
Among dizygotic twins, concordance is usually around 50 Correctfor a dominant trait.
50%
how many amino acids would it encode: ATGCCACGGAAACCCGGC?
6
If a species has a haploid number of 16 chromosomes, how many chromosomes would be in a diploid cell from this organism?
8
replication fork
A Y-shaped region on a replicating DNA molecule where new strands are growing.
congenital adrenal hyperplasia due to 21-hydroxylase deficiency.
A boy developed signs of sexual maturity at age 3.
codominance
A condition in which neither of two alleles of a gene is dominant or recessive.
Which of the potential treatments below might help a person lose weight?
A drug that causes the leptin transporter to be overactive A drug that blocks the action of neuropeptide Y
manifesting heterozygote
A female that expresses the phenotype corresponding to an X-linked gene A carrier of an X-linked recessive trait who expresses the phenotype is called a(n)
leptin
A hormone produced by adipose (fat) cells that acts as a satiety factor in regulating appetite. stimulates the hypothalamus to decrease appetite.
Hershey and Chase (1953)
A linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3' end of a new DNA fragment to the 5' end of a growing chain.
DNA profiling
A procedure that analyzes DNA fragments to determine whether they come from a specific individual.
In the parental generation, a male fruit fly with a gray body (BB) and straight wings (CC) was crossed with a female fruit fly with a black body (bb) and curved wings (cc). The F1 flies all had gray bodies and straight wings. A female F1 fly was crossed with a male fly that was homozygous recessive for both traits. The female fly had the B and C alleles on one chromosome and the b and c alleles on the other chromosome. Because the genes are linked, the expected ratio in the F2 generation would be 50% with gray bodies and straight wings and 50% with black bodies and curved wings. But four different phenotype combinations appear in the offspring, with two expected, but there were also offspring with gray bodies and curved wings and offspring with black bodies and straight wings. Which of the following best explains what happened?
A recombination occurred during the formation of the F1 female's egg cells.
Example of gene modification
A rice plant containing a gene from another organism that makes it resistant to pesticides A tomato plant containing a gene from another species to make the tomato more tasty
quantitative trait loci
A set of genes that determines a complex character that exhibits quantitative variation.
pleiotropy
A single gene having multiple effects on an individuals phenotype
A woman comes into her obstetrician's office for an exam. She is visibly pregnant but does not know how far along she is. Upon ultrasound examination, the baby's skin appears wrinkled and pink. The baby is in a head to knee position. At what stage do you estimate the baby to be?
A six month old fetus
In the future it may be possible to screen for newborns who have the mutations in the genes for neurexins and neuroligins that are associated with autism. If a baby is identified as having these mutations, what treatment might help prevent autism in this baby?
A treatment that helps mutated proteins fold correctly
epistasis
A type of gene interaction in which one gene alters the phenotypic effects of another gene that is independently inherited. When alleles at one gene locus can mask the expression of alleles at another gene locus
Based on experiments by Francis Crick and coworkers on the genetic code, predict which changes to a DNA sequence will change the reading frame. Check all that apply.
Addition of 4 nucleotides Addition of 2 nucleotides Removal of 2 nucleotides Addition of 1 nucleotide
Purines
Adenine and Guanine
Exome sequencing, when is it typically used?
After more conventional tests do not explain a person's symptoms
Which is an adult-onset condition characterized by the presence of amyloid beta deposits and neurofibrillary tangles in the brain?
Alzheimer disease
Neurofibrillary tangles of tau protein Deposits of amyloid beta protein
Alzheimer's Disease
Concordance
Among pairs of twins in whom at least one has a trait, the percentage of pairs in which both twins express the trait is the _________of the trait.
Phenocopy
An environmentally caused trait that occurs in a familial pattern, mimicking inheritance
Ligase
An enzyme that connects two fragments of DNA to make a single fragment
Primase
An enzyme that joins RNA nucleotides to make the primer using the parental DNA strand as a template.
DNA helicase.
An enzyme that unwinds the DNA double helix during DNA replication
Eye color in humans is controlled by at least two genes.
An individual with 2 recessive OCA2 An individual with 2 dominant OCA2 g
Which stage of meiosis explains Mendel's law of segregation?
Anaphase I
A diploid cell from a certain species has 16 chromosomes. In a cell undergoing cell division, homologous chromosomes are separating, with 8 chromosomes (each with two chromatids) going to each daughter cell. What is the cell cycle stage of this cell?
Anaphase I of meiosis
Who was the first to link inherited disease and protein?
Archibald Garrod
Identify an accurate statement about bipolar disorder.
As much as 10% of the genome contributes to it.
If there is a(n) association between two events, then one occurs when the other occurs
Association
How many genes are thought to affect height in humans?
At least 50
The Human Microbiome Project studied what type of organisms on and in the human body?
Bacteria
components of the human microbiome
Bacteria cells, fungal cells, protozoan cells, viruses. (NOT human skin cells, etc)
You are working in the lab, studying what you suspect to be a mitochondrial disease. You isolate mitochondria from a child with this disease, and sequence the mitochondrial genome. You also sequence the mitochondrial genomes of the parents. You are surprised to find that the child has a mutation in a very important mitochondrial gene, but that neither of her parents have this mutation. Further, both parents are healthy. What most likely explains this finding?
Because mitochondrial DNA mutates much more quickly than nuclear DNA, the girl likely incurred a new mutation in her mitochondrial DNA.
Autosomal Dominant
Both M and F are affected; M may transmit to M; each generation has at least one affected parent one mutant allele may produce the disease.
If an unborn baby becomes accustomed to large amounts of vitamin ____in the supplements that a mother takes, the baby may develop symptoms of deficiency, such as bruising and becoming infected easily.
C
Based on Mendel's laws of independent assortment and segregation, what are the possible gametes for a cell with the genotype CCBb?
CB and Cb
Genome editing (CRISPR)
CRISPR used to correct a defective copy
Chromatin
Clusters of DNA, RNA, and proteins in the nucleus of a cell
Fertility in humans is a trait that is controlled by multiple genes, and which has environmental influences, such as the health and nutrition of the potential parents. What terms describe fertility as a trait?
Complex Multifactorial
mRNA genetic code
Contains information to produce a protein
Select adult diseases that have been shown to be associated with fetal malnourishment.
Coronary artery disease Schizophrenia Stroke Hypertension
Recombination may occur between linked genes if ________ occurs during meiosis.
Cross Over
Pyrimidine
Cytosine and Thymine
Metagenomics
DNA from a group of species is collected from an environmental sample and sequenced
Phoebus Levene
DNA is made of nucleotides
Avery, MacLeod and McCarthy (1944)
DNA is the transforming principle Used DNase and protease to try and identify the genetic material
You are performing PCR for the first time in the lab. You have all your reagents ready, but you forgot to add adenine. What will be the result of your reaction?
DNA synthesis will occur until the polymerase reaches a thymine in the template strand, and then it will halt.
Lisa has one copy of a gene for an X-linked dominant disease. She is fortunate to have a very mild form of the disease, which suggests that in the relevant organs, the X chromosome containing the dominant disease allele is silenced by X-inactivation. If Lisa marries a man who does not have this allele, what will be true about her future children? Check all that apply.
Her children will all have a 50% chance of inheriting the dominant disease allele. Her sons that inherit the disease allele are likely to have a more serious form of the disease than Lisa.
Meiosis I
Homologous chromosomes form pairs two daughter cells are formed crossing over occurs the number of replicated chromosomes is halved
What is a highly regulated program of genetic switches that are turned on in specific body parts at specific times?
Human prenatal
Select practical uses of genetics and genomics that are currently in use.
Identifying victims of natural disasters Selecting crops Establishing familial relationships
intrauterine growth retardation
In the context of adult-onset inherited disorders, a fetus that does not receive adequate nutrition has _____, and though born on time, is very small.
What is the molecular mechanism underlying most accelerated aging conditions?
Inadequate DNA repair
In eukaryotic cells, parts of a molecule of mRNA called ______ are removed after transcription.
Introns
Hershey and Chase differentially tagged the DNA and proteins of bacteriophages and allowed them to infect bacteria. Which of the following statements best describes the top portion of a centrifuge tube at the end of the experiment?
It contained the viral coats and radioactive sulfur.
Identify an accurate statement about the damages caused by nicotine.
It does damage through a five-part molecular assembly that binds acetylcholine and nicotine.
Which of the following statements about LSD (lysergic acid diethylamide) is true?
It produces hallucinations, but is not addictive.
Which components of cardiovascular health are under genetic control?
Leukocyte adhesion to blood vessel walls Blood pressure Transport of lipids Blood clotting
Which of the following are symptoms of autism?
Loss of language Loss of social skills Seizure
Consider the following pedigree which follows the transmission of an autosomal recessive disease. For this disease M is the dominant allele and m is the recessive allele. What are the possible genotypes of individual 2 in the 4th generation (assume we don't yet know if she is a carrier)?
MM or Mm
Gametes from which parent determine the sex of the baby?
Male
Millie McWilliams has Bainbridge-Ropers syndrome, in which she is missing two DNA bases in the ASXL3 gene. Select the true statements about Millie and her syndrome.
Millie's disorder is caused by a gene mutation. The missing DNA bases would normally be found within Millie's exome. The traits caused by Millie's syndrome are Mendelian traits.
What is the best explanation for the inheritance pattern shown in the pedigree below?
Mitochondrial inheritance
Phenylketonuria (PKU) is a disease in humans where the function of the enzyme phenylalanine hydroxylase is impaired by mutation of the human PAH gene. Untreated, individuals with PKU can have intellectual disability, behavioral problems, and seizures. However, people who eat a diet low in phenylalanine can lead a normal life. What terms describe PKU as a trait?
Monogenic Mendelian Complex Multifactorial
Which exome sequencing approach for isolating autism genes relies on a reference genome?
Multiple unrelated affected subjects
Genes affect the number and the pattern of neuronal connections. Constant change in the nervous system structure and function is referred to as
Neural plasticity
1. Neurons use chemical signals called neurotransmitters to communicate with one another. 2. Associations between neurons called synapses are the site of neurotransmission. 3. During neurotransmission, the cell that synthesizes and releases the signaling molecule is called the presynaptic neuron. 4. Genes control the synthesis of myelin , a fatty substance that coats and insulates neurons.
Neurotransmitters, Synapses, Presynaptic neuron, Myelin
- Attaching short DNA pieces in a flow cell for sequencing- Adding DNA to tiny beads and using a laser to read the synthesized sequence- Using grapheme to measure how each base disrupts anelectrical field
Next generation sequencing techniques
mitochondrial DNA
No crossing over High exposure to oxygen free radicals Inherited from the mother only Carries 37 genes Fewer types of DNA repair than nuclear DNA Complex packaging with histones
For which of the following genes do different variants occur in European and African American populations that will lead to prescribing different cholesterol lowering medications for these two groups?
PCSK9
Werner syndrome
Patients from this disease are short because they skip the growth spurt of adolescence
homozygosity mapping
Performed on families that are consanguineous Children in this case are more likely to inherit two copies of the mutation
Patients with certain types of leukemia are screened for which alleles of the TPMT gene they have prior to receiving thiopurine drugs. Patients with certain alleles need far less of these drugs than other patients, and in fact can become sick if given the standard dose.
Pharmacogenetics
Which Russian-American biochemist identified the 5-carbon sugar ribose as part of some nucleic acids and deoxyribose as a part of other nucleic acids?
Phoebus Levene
Oogenesis
Polar bodies are formed one game is produced meiosis is completed only if fertilization occurs
Which of the following disorders become more common with age?
Polycystic kidney disease Alzheimer's disease
Genetically overloaded cells, like those that would arise from fertilization between cells that had not undergone meiosis, are called __________ cells.
Polyploid
Empiric risk
Population statistic derived from observing incidence of a trait within a population
What societal factors can affect IQ?
Poverty Not graduating from high school Incarceration (males) Having a child out of wedlock (females)
Select risk factors for autism.
Prenatal exposure to rubella Folic acid exposure late in gestation Having certain mitochondrial diseases
Recombinant DNA
Progeny that exhibit a mixing of maternal and paternal alleles on a single chromosome
Identify the effects of amphetamines on dopamine levels in the brain.
Promote an accumulation of dopamine in neural synapses Promote the release of dopamine from vesicles in presynaptic neurons
Some types of male infertility are caused by seminal fluid that is too thick for the sperm to move around properly. Predict which structures might not be working correctly in this type of male infertility
Prostate gland Seminal vesicles Bulbourethral glands
You are interested in studying diseases that might be caused by mutations that affect the endoplasmic reticulum (ER) signal sequence in proteins. You are looking at labeled proteins in cells under a microscope, and comparing cells from people with and without disease conditions. Where do you expect to find proteins with mutated signal sequences?
Proteins that are normally secreted or membrane bound will be found in the cytosol.
Which of the following statements best describes single-gene traits?
Qualitative, often providing an "all-or-none" phenotype
Rosalind Franklin and research student Raymond Gosling provided a pivotal clue to deducing the three-dimensional structure of DNA by
Question developing the image of the structure of B DNA
According to the work of Phoebus Levene, what is the major chemical distinction between RNA and DNA?
RNA has ribose and DNA has deoxyribose.
Telomeres
Repeated DNA sequences at the ends of eukaryotic chromosomes.
Which of the following systems mature last during the final trimester of a human pregnancy?
Respiratory Digestive
Hutchinson-Gilford progeria syndrome
Results from a mutation in the gene that encodes the protein Lamin A
Forms part of the enzyme that drives translation
Ribosomal RNA & Ribosomal protein
Which of the following statements are true of single-gene diseases?
Risk can be predicted for family members. Correction of the underlying genetic abnormality may be possible.
People with this disease may have a normal life span, but develop cancer or osteoporosis at a young age
Rothmund-Thomson syndrome
4. Deficiency of the neurotransmitter this in synapses is considered a likely cause of depression.
Serotonin
Meiosis II
Sister chromatids separate Four daughter cells are formed
incomplete dominance
Situation in which one allele is not completely dominant over another allele
Okazaki fragments
Small fragments of DNA produced on the lagging strand during DNA replication, joined later by DNA ligase to form a complete strand.
exome
Small portion of the genome that codes for proteins
tRNA
Structural RNA that links an amino acid to an anticodon
To determine if protein is the hereditary material, Alfred Hershey and Martha Chase used radioactive _____ to label proteins.
Sulfur
1. Genes control the synthesis of and response to neurotransmitters. True 2. Different mental and behavioral conditions can have the same symptoms. True 3. Behavioral disorders are usually single-gene disorders. False 4. Environmental influences can affect behavioral traits. True 5. Each gene that has been implicated in behavioral traits is important in just a single behavioral disorder. False
T/F
1. Some of the symptoms of schizophrenia also occur in other illnesses. True 2. Schizophrenia is a genetic disorder that is not affected by environmental influences. False 3. If a person has an identical twin who has schizophrenia, then he or she will also develop schizophrenia. False 4. The heritability for schizophrenia is high. True 5. Prenatal exposure to influenza may increase the risk of developing schizophrenia. True
T/F
A type of muscular dystrophy called Emery-Dreifuss muscular dystrophy can occur when the nesprin-2 protein contains the amino acid methionine at a certain location instead of the amino acid threonine. Why does this change in amino acid placement likely occur?
There was a mutation in the gene for nesprin-2.
Identify an accurate statement about behaviors
They control how one communicates and copes with negative feelings.
Polygenic traits have all-or-none phenotypes. False 2. The individual genes that contribute to a polygenic trait are dominant or recessive to each other. False 3. All genes that influence a polygenic trait contribute equally to the phenotype. False 4. The graph of the frequency of phenotypes in a polygenic trait has the shape of a bell curve. True 5. When a trait is polygenic, individuals cannot be categorized into classes with respect to their phenotypes. False 6. Polygenic traits may be influenced by the environment. True 7. DNA sequences that contribute to polygenic traits are called quantitative trait loci. True
T/F
A sequencing reaction generates the following DNA fragments: GTTAC, TTAC, CAGTTAC, AACAGTTAC, C, AC, ACAGTTAC, AGTTAC, and TAC. What was the template sequence of interest for this reaction?
TTGTCAATG
What components are needed to perform PCR?
Target DNA DNA primers DNA nucleotides Taq1 polymerase
Chymotrypsin is a digestive enzyme composed of a single polypeptide chain that breaks down proteins into smaller peptides. If you could observe chymotrypsin at work within the small intestine, what is the most complex level of protein structure you would be observing?
Tertiary
Homozygosity mapping
The "Blue Fugates", an inbred family who lived in the hills of Kentucky in the 1800s, had children with blue skin. It was discovered that they suffered from the recessive genetic disease methemoglobinemia. If genome wide association studies had been available at that time, what would have been the best type of study to use to identify the cause of their blue skin?
What affects eye color in humans?
The OCA2 gene The HERC2 gene Peaks and valleys on the back of the iris
Which account for the occurrence of migraine headaches?
The action of three genes Environmental influences such as food choices and stress
In order to determine if a patient with a syndrome inherited a recessive disease or had a de novo mutation, who all MUST undergo genome or exome sequencing?
The child Mom Dad
You are studying the levels of proteins in different tissue types in samples from mice. The levels of some proteins are rather uniform among tissue types. In contrast, you are surprised to find that a protein called class III β-tubulin is present only in brain tissue from the mouse and is undetectable in other tissues. What is the most likely explanation for this finding?
The difference is most likely due to the action of) transcription factors
You are evaluating a child who has tested positive for one of the C4A alleles associated with schizophrenia. You are aware of a new drug that can reduce synaptic pruning in patients who are susceptible to developing schizophrenia. Why must you proceed with caution before giving this patient the drug?
The disease has a significant environmental component, so not everyone who has these gene variants will develop the disease.
Archibald Garrod
The first to suggest that genes dictate phenotypes through enzymes that catalyze specific chemical reactions in the cell., Reported Alkaptonuria as the first human example of what is now known as Mendelian inheritance.
You are a doctor. A patient comes into your office who is 5'10'' and 220 pounds. Based on his BMI what advice should you give him?
The man is obese and likely needs to make major changes to his diet and exercise routines.
Prevalence
The number or proportion of cases of a particular disease or condition present in a population at a given time. a genetic disorder is the proportion of individuals in a population who have the disorder at a specific time.
incidence
The number or rate of new cases of a particular condition during a specific time.
incidence
The number or rate of new cases of a particular condition during a specific time. The number of new cases of a genetic disorder diagnosed per year in a population of a given size is the incidence of the disorder.
Centromeres
The point on a chromosome by which it is attached to a spindle fiber during cell division.
When the cystic fibrosis gene was discovered in 1989, only one mutation was described, and a diagnostic test was developed to detect it. Over the years, as more mutations were discovered, they were added to the test panel. Today, most pregnant women are offered a CF test that detects 100 or so alleles, although more than 1600 mutations have been discovered. Which of these is reflected by the given facts?
The presence of multiple alleles
Coefficient of relatedness
The proportion of genes that two people with a certain relationship share
heritability
The proportion of phenotypic variance for a trait that is due to genetic differences in a population is the trait
What happens when a human eats protein from an animal?
The protein is broken down into amino acids, which are then incorporated into human proteins.
Pharmacogenomics
The study of the influence of genetic factors on drug response that result in the absence, overabundance, or insufficiency of drug-metabolizing enzymes
Dermatoglyphics
The study of the pattern of epidermal ridges (fingerprints)
evidence that suggests addiction has a genetic component
There is a two- to threefold increase in risk of addiction for adopted individuals with one affected biological parent. People homozygous for a certain allele of the dopamine D(2) receptor gene variant are over-represented among those with alcoholism. Certain variants within the nicotinic receptor lead to a desire to continue smoking after the first cigarette.
A pair of college sweethearts do a DNA test to find out their respective ancestries. They are shocked to find that they share nearly 1% of their genome. What is their likely relationship?
Third cousins
Microcephaly
abnormally small head
In the nuclei of white blood cells, Friedrich Miescher discovered an unusual substance that was______
acidic and contained nitrogen and phosphorus
Microbiome
all of the microorganisms that live in a particular environment, such as a human body
lethal
allele may result in a phenotypic class that does not survive long enough to reproduce.
A human male inherits
an X chromosome from his mother and a Y chromosome from his father.
Neurotransmitters bind to receptors on postsynaptic neurons in contrast to Blank______ that binds to receptors on presynaptic neurons.
anandamide
The opposing orientation of the two nucleotide chains in a DNA molecule is called
antiparallelism
Prokaryotic Cells
bacteria and archaea -no nucleus or other membrane-bound organelles
Binding proteins
bind a specific substrate, either to sequester it in the body or hold its concentration at steady state
melanocytes
cells that produce melanin, In the skin, melanin is found in packets called melanosomes inside cells
You are studying a drug that blocks translation in bacteria. You want to know more about its mechanism of action. You treat bacteria with the drug and isolate mRNAs with their associated proteins from the treated bacteria. In bacteria treated with the drug, you find the small ribosomal subunit bound to the mRNAs, but not the large subunit. In which stage does this drug arrest translation?
initiation
30-nm fiber
interactions between nucleosomes cause the thin fiber to coil or fold into this thicker fiber
The purpose of the sugar-phosphate backbone in a DNA molecule is to
join nucleotides into long chains
When comparing the medical and biochemical profiles for astronaut Scott Kelly after returning from the International Space Station with those of his twin brother and fellow astronaut Mark Kelly who remained on earth, researchers found changes in Blank______.
lengths of chromosomal telomeres expression of genes controlling proteins in urine and in inflammation the organisms found in the intestinal microbiome
The male-specific region of the Y chromosome
lies between the two pseudoautosomal regions.
Excessive use of opiates Blank______ the level of the body's production of Blank______.
lowers; endorphins
information to produce a protein
mRNA, Gene
X-linked genes have different patterns of expression in females and males because
males have only one copy of these genes.
The number of ridges in a fingerprint is influenced by _____.
many genes early development in the wombThe number of ridges in a fingerprint is influenced by Blank______.
Chargaff (1950)
measured A,C,T,G in different species, found A=T, C=G
empiric risk
measures the likelihood that a trait will recur based on incidence The chance that a polygenic complex trait will occur in an individual
A woman has a female calico cat with a Manx tail. She wants to mate her with a male calico, but can't find one. Male calicos are rare; the only ones have the sex chromosome constitution XXY. Male calicos are therefore rare because
most male cats have only one X chromosome, so it cannot be shut off.
X-linked dominant traits are typically expressed
much more severely in males because they have only one X chromosome.
Essential protein
must be obtained in the diet
Enkephalins
opioids that are widespread throughout the brain and dorsal horn of the spinal cord and are believed to reduce pain sensation by inhibiting the release of substance P
In humans, if the SRY gene is not expressed, the unspecialized gonads develop into
ovaries.
Familial advanced sleep phase syndrome (FASPS) is caused by mutations in the gene
period 2
The sugar-phosphate backbone is formed due to strong attachments between the deoxyribose sugars and the phosphates, called
phosphodiester bonds
Alfred Hershey and Martha Chase proved that DNA is the hereditary material when they discovered that the part of the virus that entered bacteria and directed them to mass produce more virus contained _____.
phosphorus
etal alcohol syndrome (FAS).
physical and cognitive abnormalities in children caused by a pregnant woman's heavy drinking. In severe cases, symptoms include intellectually impaired. Children with FAS have small heads and flat faces.
Fredrick Griffith discovered bacterial transformation when he was studying
pneumonia using mice
An individual with familial advanced sleep phase syndrome (FASPS) is likely to
promptly fall asleep at the same exact time each night
US microbiologists Alfred Hershey and Martha Chase showed that _____. Multiple choice question.
protein is not the hereditary material
Histone
protein molecule around which DNA is tightly coiled in chromatin
A child develops a genetic disease which affects neither of his parents
recessive
Homosexuality
reflects the input of a number of genes and environmental factors.
Nucleosome
repeating subunit of chromatin fibers, consisting of DNA coiled around histones
Cohort Study
researchers follow a large group of individuals over time.
Sex ratio at birth is called the __________ sex ratio.
secondary
genome-wide association study
seeks correlations between SNP patterns and phenotypes in large groups of individuals.
The seminiferous tubules are the site where sperm cells
undergo development
Wilkins & Franklin (1953)
x-ray diffraction of dna showed it was helix determined that dna has a repeating structure and a uniform diameter