Deck 21: Population Genetics and Evolution at the Population, Species, and Molecular Levels

Question 1

If the frequencies of two alleles in a population are 0.1 and 0.2, what is the chance that an individual randomly chosen from this population is heterozygous for these two alleles?

A) 0.1 + 0.2 = 30%
B) 0.1 * 0.1 = 1%
C) 0.1 * 0.2 = 2%
D) 2 * 0.1 + 0.2 = 60%
E) 2 * 0.1 * 0.2 = 4%

Answer 1

E

Question 2

The Paternity Index (PI) is calculated by dividing by .

A) the probability that the putative father is the real father; the probability that putative father is not the real father
B) the probability that the nonmaternal allele comes from the putative father; the probability that the allele comes from another male in the population
C) the probability that the nonmaternal allele comes from a random male; the probability that the allele comes from another male in the father's population
D) the probability that the childs allele comes from the mother; the probability that the childs allele comes from the father
E) the probability putative father has the child's allele; the probability that the allele comes from another male in the population

Answer 2

B

Question 3

First- degree relatives share 50% of their alleles, second- degree relatives share 25% of their alleles, and third- degree relatives share 12.5% of their alleles. Which of the following are third degree relatives?

A) grandparents of an individual
B) parents and their children
C) siblings
D) the aunts or uncles of an individual
E) none of these relationships is third- degree

Answer 3

D

Question 4

CODIS markers are chosen that do not occur in coding regions of genes so that they do not disrupt what?

A) promoters
B) intergenic regions
C) gene expression
D) introns
E) codons

Question 5

For paternity testing to work, which of the following must be true?

A) A child can inherit all of their alleles from their father.
B) The true mother must be known.
C) The father and the mother cannot be identical twins.
D) A child must inherit half of their alleles from their father, the other half come from the mother.
E) The father must be homozygous for any allele that is tested.

Question 6

Applying the exclusion principle to forensic genetics allows investigators to .

A) exclude any suspects with at least one allele that matches a crime scene
B) include all suspects until guilt is established
C) include all suspects with at least one allele that matches a crime scene
D) exclude any samples not found at the crime scene
E) exclude any suspects whose DNA does not contain an allele that was detected at the crime scene

Question 7

Genetic markers used for forensic analysis are usually .

A) codominant, where only the recessive allele can be detected
B) dominant, so the presence of one of the two alleles is obvious
C) codominant, where only the dominant allele can be detected
D) recessive, where an individual is positive if they are homozygous
E) codominant, where each allele can be detected separately

Question 8

Genealogical analysis considers all of the following except?

A) place of birth
B) the extent of shared SNPs between individuals
C) the frequency of alleles in reference populations
D) date of birth
E) the genotype of the tested individual

Question 9

CODIS markers occur at no greater than 20% for any one allele so each marker has at least 5 alleles in a population, these features help ensure high levels of what?

A) similarity between individuals
B) heritability
C) homozygosity
D) heterozygosity
E) inbreeding

Question 10

A putative father in paternity case is heterozygous for alleles 20 and 23 of the D21S11 gene. The frequency of allele 20 is 0.1 and the frequency of allele 23 is 0.2. A child is born with a nonmaternal 23 allele at its D21S11 gene. What is the Paternity Index (PI) for this putative father in this case?

A) 0.2 / 0.2 = 1
B) 0.5 / 0.2 = 2.5
C) 1 / 0.2 = 5
D) 0.2 / 0.1 = 2
E) 0.2 * 0.1 = 0.02

Question 11

Calculate the Combined Paternity Index (CPI) for a father with each of the following PIs: FGA10 = 1.25; D3S135816 = 3.0; TPOX33 = 4.4

A) 1.25 / 3.0 / 4.4 = 0.095 (rounded)
B) 1.25 + 3.0 + 4.4 = 8.65
C) 1.25 * 3.0 * 4.4 = 16.5
D) 1.25 + 3.0 + 4.4/100 = 0.0865
E) (1) 1.25 + (0.5) 3.0 + (1) 4.4 = 7.15

Question 12

CODIS markers are analyzed _ .

A) using low- resolution electrophoresis
B) by agarose gel electrophoresis
C) by capillary electrophoresis
D) only by the Federal Bureau Investigation (FBI) in certified crime labs
E) by DNA sequencing

Question 13

What is the statistical principle underlying genetic health risk assessment is called?

A) association
B) the placebo effect
C) case/control
D) determinism
E) causality

Question 14

A putative father in paternity case is homozygous for allele 23 of the D21S11 gene. The frequency of allele 23 is 0.1. A child is born with a nonmaternal 23 allele at its D21S11 gene. What is the Paternity Index (PI) for this putative father in this case?

A) 1 * 0.1 = 0.1
B) 0.5 / 0.1 = 5
C) 1 / 0.1 = 10
D) 0.1 / 0.1 = 1
E) 0.1 * 0.1 = 0.01

Question 15

Genetic health risk assessment data can be used to report all of the following except?

A) a parents risk of passing on a disease- associated allele to their children
B) the contribution of the tested alleles to an individuals risk of developing a particular disorder
C) the presence of a disease- associated allele in an individual
D) the frequency of the disease causing allele in the population
E) an individuals exposure to tobacco

Question 16

Siblings are expected to share % of their alleles with their nieces or nephews.

A) 50%
B) 12.5%
C) 25%
D) 0%
E) 5%

Question 17

Which of the following could not be used for paternity testing?

A) The child's DNA
B) CODIS markers
C) DNA from the Y- chromosome
D) mitochondrial DNA
E) DNA from hair

Question 18

To help the Abuelas de Plaza de Mayo (Grandmothers of May Square) Mary- Claire King analyzed
to identify illegally adopted children?

A) mitochondrial DNA
B) DNA from hair
C) DNA from the Y- chromosome
D) CODIS markers
E) paternity testing

Question 19

Applying the exclusion principle to paternity testing allows investigators to .

A) include all father with at least one allele that matches the child's non- maternal allele
B) exclude any father with at least one allele that does not match the child's non- maternal allele
C) include any father with at least one gene that matches both of the child's alleles
D) exclude all father with at least one allele that matches the child's non- maternal allele
E) include any father with at least one allele that matches both of the child's alleles

Question 20

If the frequencies of two alleles in a population are 0.1 and 0.2, what is the chance that an individual in this population is homozygous for the allele with the frequency of 0.1?

A) 0.1 * 0.1 = 1%
B) 2 * 0.1 * 0.1 = 2%
C) 0.1 / 0.1 = 1
D) 0.1 + 0.1 = 20%
E) 0.1 + 0.2 = 30%

Question 21

The discovery of non- coding sequences that are conserved in a wide range of related species suggests that these sequences are important for what?

A) cancer
B) the differences between those related species
C) migration
D) gene regulation
E) cell division

Question 22

The selection for different alleles affecting the expression of the LCT gene in milk- drinking human populations is an example of?

A) genetic drift
B) hitchhiking
C) common ancestry
D) convergent evolution
E) a selective sweep

Question 23

Darker skin pigmentation in the ancestors to all humans may have been an adaptation to increase UV- resistance that followed the loss of fir in early hominids. The subsequent loss of pigmentation in at least two human populations may have conferred what advantage in those populations, both of which inhabited areas with less sun exposure?

A) less pigmentation occurred not by selection, but by genetic drift
B) less pigmentation increased energy needs
C) less pigmentation decreased vitamin D synthesis
D) less pigmentation increased vitamin D synthesis
E) less pigmentation increased melanin synthesis

Question 24

Selection for two different alleles of the hypoxia inducible factor pathway gene (EPAS1), one in Tibetan and the other in Ethiopian populations suggests that these two population share what?

A) selective pressure related to altitude
B) recent common ancestry
C) selective pressure for high gene expression
D) This result suggests that these two populations have nothing in common.
E) no common ancestry

Question 25

Phylogenetics, the study of evolutionary relationships between organisms predicts that closely related species will share which of the following when compared to species that diverged longer ago?

A) more traits
B) fewer CNVs
C) more DNA sequence
D) all of these statements are assumptions made by phylogenetics
E) none of these statements are assumptions made by phylogenetics

Question 26

Selection for an allele is expected to have what effect on neutral alleles located on the same chromosome as the selected allele?

A) the neutral sites will not change in frequency in the population, because they are neutral
B) the neutral alleles will become selectively advantageous
C) the neutral sites will increase in frequency in the population
D) there will not be an effect of the selected allele on the neutral allele because alleles of different gene assort independently
E) the neutral sites will decrease in frequency in the population

Question 27

In which regions of the human genome would you expect to find the most genetic diversity and why?

A) There is no meaningful difference between coding and non- coding regions in terms of genetic diversity.
B) In non- coding regions, because there is selective pressure to alter non- coding sequence.
C) In coding regions, because there is selective pressure to alter amino acid sequence in proteins.
D) In non- coding regions, because there is less selective pressure to maintain non- coding nucleotide sequence.
E) In coding regions, because there is selective pressure to preserve amino acid sequence in proteins.

Question 28

The presence of similar DNA sequences in sharks, whales and humans, but not in chimpanzees suggests?

A) the DNA codes for a protein
B) that humans are derived from chimpanzees
C) the DNA was gained in elephants, mice and humans, but not chimpanzees .
D) the DNA was lost in chimpanzees
E) none of these hypotheses is supported by this observation

Question 29

Domestication had what genetic effects on Maize compared to Teosinte?

A) domestication had no genetic effect on Maize
B) domestication increased the number of genes in Maize
C) domestication decreased the number of genes in Maize
D) domestication increased the diversity of Maize
E) domestication decreased the diversity of Maize

Question 30

Mitochondrial DNA is useful to studies of human history because .

A) it is inherited by both parents, allowing researchers to trace DNA from maternal and paternal origins
B) it is inherited maternally and its sequence changes very little over time
C) it is inherited maternally and its sequence is typically more diverse than nuclear DNA
D) it is inherited paternally
E) it can be used to identify the mother of any human

Question 31

An allele that is shared by both chimpanzees and humans is said to be .

A) conserved
B) derived
C) ancestral
D) a human- specific gene
E) both conserved and ancestral

Question 32

The ability to travel rapidly over the Earth is expected to have what effect on human populations?

A) the differentiation between populations with increase
B) the differentiation between populations with decrease
C) human populations will diverge from each other
D) the differentiation between populations with remain steady
E) none of these is expected to result from rapid global travel

Question 33

On which continent would you expect to find the most human genetic diversity and why?

A) Africa, because it has the oldest human populations, containing alleles that originated long ago and have evolved since.
B) Australia, because it has the oldest human populations.
C) Australia, because it has had a relatively small population size for a relatively short amount of time.
D) Europe, because it had waves of human migration from other parts of the world over the course of many thousands of years.
E) South America because it was one of the last continents to be inhabited by humans.

Question 34

The loss of genetic diversity at linked neutral loci near a selected site is evidence of what?

A) migration
B) inbreeding
C) genetic drift
D) hitchhiking
E) a haplotype

Question 35

Human- specific traits are found by comparing humans to what?

A) other humans
B) whales
C) apes
D) Denisovans
E) plants

Question 36

Mutations affecting can alter the expression of a gene without affecting its coding sequence.

A) coding sequence
B) non- coding sequence
C) exons
D) amino acid sequence
E) mutations in any of these regions could affect a gene's coding sequence

Question 37

In which of the following continents would you expect the human population to have the fewest alleles derived from Denisovans?

A) Europe
B) Asia
C) South America
D) North America
E) African

Question 38

On what continent did hominids evolve?

A) South America
B) Africa
C) Asia
D) Europe
E) North America

Question 39

Portions of the nuclear DNA of many modern humans have similarity to either Denisovan or Neanderthal nuclear DNA, however human mitochondrial DNA (mtDNA) is more similar to Denisovan mtDNA than to Neanderthal mtDNA. Why might this be the case?

A) Modern humans are derived from matings between Denisovan females and human males
B) Modern humans are the common ancestors of both Denisovans and Neanderthals
C) Modern humans are derived from matings between Denisovan males and human females
D) Modern humans are derived from matings between Neanderthal females and human males
E) Modern humans are derived from matings between Denisovan females and Neanderthal males

Question 40

All of the following are expected to increase genetic diversity in a population except?

A) random mating
B) immigration
C) small population size
D) low selective pressure
E) large population size

Question 41

Cancer cells can divide indefinitely, which is also known as .

A) mitotic arrest
B) cellular immortality
C) checkpoint function
D) resistance to cell death
E) cellular differentiation

Question 42

The most common cause of cancer formation is _ .

A) inheriting a tumor
B) germline mutations
C) mutation in a single gene
D) accumulation of mutations in a large number of genes
E) recessive alleles

Question 43

A proto- oncogene has what characteristics?

A) a gene that inhibits cell division and when functioning normally, leads to cancer progression
B) a gene that inhibits apoptosis and when mutated prevents tumor metastasis
C) a gene that regulates the cell cycle in response to hormones
D) a gene that promotes cell division and when functioning normally, leads to cancer progression
E) a gene that promotes cell division and, when mutated, leads to cancer progression

Question 44

Benign cell masses are known as .

A) malignant tumors
B) apoptosis
C) dysplasia
D) neoplasia
E) metastatic cells

Question 45

The modern view of cancer describes the cells of a malignant tumor as _ _.

A) normal cells which have been converted to cancer cells by hormones
B) a complex mixture of cells, some malignant and some not
C) genetically identical to the surrounding somatic cells from the same patient
D) abnormal cells confined to a tissue within the patient
E) clonal, each being genetically identical to the other cells in the tumor

Question 46

Familial cancer often includes the inheritance of _.

A) predisposition to cancer
B) homozygous mutations
C) developmental abnormalities
D) somatic mutations
E) missing chromosomes

Question 47

Burkitt's lymphoma results from a/an , which causes the misexpression of the protein cMyc.

A) chemotherapy drug
B) point mutation
C) deletion
D) heat shock
E) chromosomal translocation

Question 48

Cells whose normal function involves preventing cell division are generally characterized as .

A) transcription factors
B) apoptotic genes
C) oncogenes
D) pseudogenes
E) tumor suppressor genes

Question 49

Cancer susceptibility can run in families due to _ .

A) germline mutation
B) population migration
C) inbreeding
D) sporadic causes
E) somatic mutation

Question 50

The 'two- hit' hypothesis suggests that .

A) once one allele of a gene is mutated, the other allele must be mutated in order to result in cancer
B) both eyes must contain mutations in the RB1 gene in order to develop retinoblastoma
C) two mutations in the same gene are required for that gene to become oncogenic
D) mutations in one gene promote cancer and mutations to other genes prevent cancer
E) mutations in two genes in the same cell is usually required for cancer progression

Question 51

Age is the greatest of all risk factors for cancer because _.

A) older people have weaker immune systems
B) tumor suppressors do not work as well in older people
C) germline mutations accumulate with age
D) somatic mutations accumulate with age
E) cell division is rare in older people

Question 52

Cancer therapy includes which of the following?

A) modified immune cells
B) drug treatments targeting dividing cells
C) radiation targeting cancerous cells
D) drugs targeting specific enzymes/proteins
E) All of these are possible treatment strategies.

Question 53

Inflammation can aide tumor growth by promoting which of the following?

A) altered metabolism
B) mutagenesis
C) drug resistance
D) genome stability
E) angiogenesis

Question 54

All of the following are hallmarks of cancer except _ .

A) apoptosis
B) evasion of growth suppression
C) metastasis
D) sustained cell production
E) angiogenesis

Question 55

Sporadic retinoblastoma is often confined to one eye, not both eyes, because homozygous RB1 mutations .

A) affect only one eye
B) are embryonic- lethal
C) are rare
D) prevent cell division
E) require one other mutation, a 'second- hit' to cause cancer

Question 56

Mutation in the DNA repair checkpoint gene TP53 underlie Li- Fraumeni syndrome which can be diagnosed based on _ _.

A) lack of mutations over many generations
B) many different types of cancer in multiple members of the same family
C) inherited breast cancer
D) recurrence of cancer in the same organ in multiple family members
E) melanoma

Question 57

Common mutational targets affecting cancer susceptibility include all of the following except .

A) DNA repair genes such as BRCA1
B) the cell cycle
C) mitochondrial function
D) checkpoint genes
E) growth- limiting genes such as APC

Question 58

Chronic myelogenous leukemia results from a translocation which allows cells to express .

A) a missing chromosome arm
B) a fusion protein
C) a loss- of- function allele
D) too much protein from a normal gene
E) a recessive allele

Question 59

Most cancers are caused by _ mutations whereas a minority of cancers is caused by mutations.

A) inherited; somatic
B) germline; somatic
C) somatic; random
D) germline; inherited
E) somatic; germline

Question 60

Which of the following genes is responsible for pausing the cell cycle long enough for radiation- induced DNA damage to be repaired?

A) Both PD- L1 and KRAS
B) KRAS
C) Both PD- L1 and TP53
D) TP53
E) PD- L1

Question 61

Fetal cell sorting can be performed to collect from which provide information about the genotype of a fetus.

A) metabolic compounds; maternal blood
B) fetal cells; maternal blood
C) metabolic compounds; amniotic fluid
D) fetal cells; a heel stick
E) maternal cells; amniotic fluid

Question 62

Two parents with a dominant trait have a child who shows the normal phenotype. What is the chance that that child is a carrier of the trait?

A) the chance that an unaffected child is a carrier is less than 50%
B) the chance that an unaffected child is a carrier is 50%
C) the chance that an unaffected child is a carrier is 0%
D) the chance that an unaffected child is a carrier is 75%
E) the chance that an unaffected child is a carrier is 2/3

Question 63

Testing to determine if someone is heterozygous for a recessive allele is called .

A) carrier testing
B) presymptomatic testing
C) newborn genetic testing
D) karyotyping
E) direct- to- consumer testing

Question 64

Phenylketonuria (PKU) is detected in newborns when are measured in blood samples.

A) maternal cells
B) single nucleotide polymorphisms (SNPs)
C) chromosome abnormalities
D) metabolites
E) triplet repeat expansions

Question 65

Inspecting a fetus by ultrasound can reveal which of the following?

A) translocations
B) cystic fibrosis
C) karyotype
D) morphological abnormalities such as cleft lip.
E) Phenylketonuria (PKU)

Question 66

Genetic testing includes all of the following except .

A) carrier testing
B) presymptomatic testing
C) newborn testing
D) prenatal testing
E) all of these are forms of genetic testing

Question 67

Polymerase chain reaction (PCR) is used to detect which type of genetic variation?

A) inversions
B) monosomy
C) triplet repeat expansions
D) translocations
E) aneuploidy

Question 68

The male partner has a rare autosomal- recessive trait and the female partner does not, their first child however has the trait. What do you tell them about the chance that their next child will have the trait?

A) the chance is 2/3
B) the chance is 0%
C) the chance is 75%
D) the chance is 25%
E) the chance is 50%

Question 69

The child of a normal parent and a parent who develops Huntington disease has a _ chance having a disease allele.

A) 75%
B) 100%
C) 25%
D) 0%
E) 50%

Question 70

Genetic screening to assess disease risk among individuals in a subpopulation is called _.

A) karyotyping
B) presymptomatic testing
C) in vitro fertilization
D) prenatal screening
E) community- based screening

Question 71

The recommended uniform screening panel (RUSP) includes tests for conditions that have all of the following characteristics except .

A) treating the condition is not possible
B) the test can be performed with a blood sample
C) the condition must be reliably detected by the test
D) the condition can be treated by medical intervention
E) the condition can be dominant

Question 72

Non- invasive prenatal genetic screening capable of analyzing the nucleotide sequence of DNA includes which technique(s)?

A) fetal cell sorting
B) amniocentesis
C) preimplantation screening
D) chorionic villus sampling
E) karyotying

Question 73

Direct- to- consumer testing offers clients the chance to .

A) have genetic testing performed on people without their consent
B) assess their risk of several genetic conditions
C) determine their chances of having a miscarriage
D) have their results evaluated by a medical professional
E) none of these options is available by direct- to- consumer testing

Question 74

Genetic association between a genetic variant and a trait means .

A) that the genetic variant is not relevant to the trait
B) that the associated genetic variant causes the trait/condition
C) that individuals with an associated allele are certain to have the trait
D) that the trait/condition is caused by a single allele
E) that individuals with an associated allele are more likely than those without the allele to have the trait

Question 75

The only form of genetic testing that is mandated in the United States is .

A) paternity testing
B) newborn testing
C) community- based testing
D) prenatal testing
E) carrier testing

Question 76

Pharmacogenetic screening aims to reveal what kind of trait?

A) disorders that cause imbalance of metabolic compound in the blood
B) susceptibility to infection
C) sensitivity to drugs or adverse effects of drugs
D) susceptibility to autoimmune disease
E) susceptibility to disease

Question 77

Unlike many other genetic disorders, Huntington's disease is caused by a full penetrance disease allele. Full penetrance means what?

A) The longer the allele (more triplet repeats), the more likely the disease is to occur in an individual.
B) Individuals with a disease allele are almost certain to get Huntington's disease.
C) Heterozygotes are just as likely to get Huntington's disease as homozygotes.
D) There are environmental factors beyond age that are also required for an individual to get Huntington's disease.
E) There are other genes that are also required for an individual to get Huntington's disease.

Question 78

If both parents are carriers of a recessive disease allele, what is the chance that one of their unaffected children is also a carrier?

A) the chance that an unaffected child is a carrier is 50%
B) the chance that an unaffected child is a carrier is 2/3
C) the chance that an unaffected child is a carrier is less than 50%
D) the chance that an unaffected child is a carrier is 0%
E) the chance that an unaffected child is a carrier is 75%

Question 79

Karyotyping is used to detect which type of genetic variation?

A) metabolic conditions
B) triplet repeat expansions
C) translocations
D) SNPs and translocations
E) single nucleotide polymorphisms (SNPs)

Question 80

Alzheimer disease is associated with variation in the gene APOE. Thus, individuals with APOE mutations are .

A) less likely to have parents who have/had Alzheimer disease
B) certain to have Alzheimer disease
C) more likely to respond to drugs that treat Alzheimer disease than individuals without APOE mutations
D) more likely to get Alzheimer disease than individuals without APOE mutations
E) less likely to have children who are susceptible to Alzheimer disease