ls7b week 1-3 PEQs and review questions

The gene for nose shape is found on the X chromosome. Round nose is dominant to pointed nose. Human individuals with XXY (an additional X chromosome) are designated male. Individuals with XO (only one X chromosome) are designated female. Identify the possible nondisjunction events (rare mistakes during meiosis) that could explain the phenotype of the offspring. An XY parent with a round nose and a XX parent with a round nose have an offspring with Klinefelter Syndrome (genotype XXY) with a pointed nose. A. Nondisjunction could have occurred in meiosis 1 of the XX parent B. Nondisjunction could have occurred in meiosis 1 of the XY parent C. Nondisjunction could have occurred in meiosis 2 of the XX parent D. Nondisjunction could have occurred in meiosis 2 of the XY parent

C. Nondisjunction could have occurred in meiosis 2 of the XX parent

Alex and Anna are two people who are considering having children together. Alex, his father (XY parent), and his mother (XX parent) all have blood type B. His younger XX siblings and his XY siblings have blood type O. Anna, her XX parent, and her younger XY sibling all have blood type A. Anna's XX sibling and older XY sibling both have blood type O. Anna's XY parent has type B. What is the probability that Alex and Anna's first offspring will have blood type AB? A) 1/4 B) 1/8 C) 1/6 D) 1/3

D) 1/3

A newly discovered strain of Anopheles gambiae, a mosquito, is found to be resistant to a particular insecticide due to a new allele at a specific locus. When individuals of this strain are mated with individuals of an insecticide-susceptible strain of A. gambiae, all offspring are susceptible. If males and females of these susceptible offspring are then mated with one another, what proportion of offspring do you expect will be resistant? a) 0.25 b) 0.33 c) 0.5 d) 0.75 e) 0 (none)

a) 0.25

If all variation among individuals in a population is due to differing genotypes alone, heritability is _____, and the slope of the line used to measure it is _____. a) 100%: 1.0 b) 50%; 0.5 c) 100%; 0.5 d) 0%; 0 e) 50%; 1

a) 100%: 1.0

Which of the statements best reflects the extent to which we can distinguish the effects of genes and the environment on the expression of a complex trait? a) In a group of individuals of the same sex, about 80% of the variation in height among individuals is due to genetic differences and 20% is due to environmental differences. b) about 80% of an individual's height is determined by genes and 20% by environment c) if one individual is 60 inches tall and another is 70 inches tall, they differ in about 80% of their genes d) for identical twins raised in the same environment, height should not differ by more than 20%

a) In a group of individuals of the same sex, about 80% of the variation in height among individuals is due to genetic differences and 20% is due to environmental differences.

The addition rule requires which option? a) Two outcomes (such as having the genotype BB or Bb) are mutually exclusive in an organism. b) more than one outcome (such as two different genotypes resulting in black fur) can occur simultaneously in an organism

a) Two outcomes (such as having the genotype BB or Bb) are mutually exclusive in an organism.

in crosses involving linked genes, recombinant offspring result from a) a crossover b) mendelian segregation c) independent assortment of alleles d) sex-linked inheritance e) Mendelian segregation and independent assortment of alleles

a) a crossover

when do sister chromatids separate in meiosis? a) anaphase 2 b) metaphase 2 c) telophase 1 d) anaphase 1

a) anaphase 2

in a homozygous genotype: a) both alleles for a given trait are the same b) both alleles for a given trait are the same, and the individual will be phenotypically dominant c) the individual will be phenotypically dominant d) the individual will be phenotypically recessive e) the two alleles for a given trait are different

a) both alleles for a given trait are the same

which of the choices is a characteristic of meiotic cell division? a) cell division results in the production of gametes b) meiotic cell division requires two rounds of DNA replication c) the cells produced by meiosis are genetically identical d) meiotic cell division ultimately results in the formation of two cells

a) cell division results in the production of gametes

a phenotype always refers to something that you can see with your eyes, like hair color or eye color a) false b) true

a) false

the observable characteristics of an organism constitute its genotype a) false b) true

a) false

true breeding plants are typically heterozygous for most genes a) false b) true

a) false

an organism that has 2 different alleles of a given gene has a(n) _____ genotype a) heterozygous b) homozygous c) dizygous d) aneuploid e) heteromorphic

a) heterozygous

sites in the genome that are more susceptible to mutations than others are called: a) hotspots b) genes c) mutation spots d) noncoding DNA e) risk factors

a) hotspots

The gene for nose shape is found on the X chromosome. Round nose is dominant to pointed nose. Human individuals with XXY (an additional X chromosome) are designated male. Individuals with XO (only one X chromosome) are designated female. Identify the possible nondisjunction events (rare mistakes during meiosis) that could explain the phenotype of the offspring produced by an XY parent with a pointed nose and a XX parent with a round nose have an offspring with Klinefelter Syndrome (genotype XXY) with a pointed nose. Select all that apply. a) nondisjunction could have occurred in meiosis 1 of the XY parent b) nondisjunction could have occurred in meiosis 2 of the XY parent c) nondisjunction could have occurred in meiosis 2 of the XX parent d) nondisjunction could have occurred in meiosis 1 of the XX parent

a) nondisjunction could have occurred in meiosis 1 of the XY parent c) nondisjunction could have occurred in meiosis 2 of the XX parent

an allele is: a) one of several forms of a gene b) the location of a gene in a chromosome c) none of the other answer options is correct d) the expression of a trait in an individual e) the particular combination of genes for a given trait in a given organism

a) one of several forms of a gene

Single-nucleotide polymorphisms (SNPs) can be detected by microarrays, which are wafer-like substrates to which millions of short stretches of DNA are attached. A microarray consists of many different squares, each one containing a different sequence of single-stranded DNA to which fluorescently labeled strands of DNAs from patients with different SNPs can hybridize. If one square will hybridize with an SNP having a C-G base pair at a particular site, and an adjacent square will hybridize with an SNP having a T-A base pair at the same site, which of the genotypes will hybridize with both squares and make them fluoresce? a) the heterozygous C-G/T-A genotype b) all of the genotypes hybridize with both squares c) the homozygous T-A/T-A genotype d) the homozygous C-G/C-G genotype

a) the heterozygous C-G/T-A genotype

Two genes, A and B, are found on the same chromosome. One chromosome has alleles A and B, while its homolog has alleles a and b. If genes A and B are so closely linked that the recombination frequency is 0 percent, only AB and ab gametes will be produced during meiosis. a) true b) false

a) true

a Punnett square can be used to interpret the results of a testcross a) true b) false

a) true

Consider a gene with four alleles: A1, A2, A3, and A4. In the cross A1A2 x A3A4, how many offspring genotypes are possible? a) 6 b) 4 c) 3 d) 2 e) 5

b) 4

Consider a gene with four alleles: A1, A2, A3, and A4. How many distinct heterozygous genotypes are possible? a) 4 b) 6 c) 2 d) 5 e) 3

b) 6

Hemophilia is a sex-linked recessive trait in humans. If a carrier XX individual (heterozygous for the trait) mated with a non-affected XY individual, what would be the expected outcome(s)? Select all that apply. a) half of the XX offspring would have hemophilia b) None of the XX offspring would have hemophilia c) None of the offspring would have hemophilia d) Half of the XY offspring would have hemophilia

b) None of the XX offspring would have hemophilia d) Half of the XY offspring would have hemophilia

most complex traits are: select all that apply a) inherited in pedigrees showing simple Mendelian patterns b) affected by environmental factors c) affected by interactions between genes and environmental factors d) heterozygous for all alleles affecting the trait e) affected by multiple genes f) homozygous for all alleles affecting the trait

b) affected by environmental factors c) affected by interactions between genes and environmental factors e) affected by multiple genes

genes located on the X-chromosome: a) are always recessive to genes located on the y chromosome b) are called x-linked genes c) are contributed solely by the female parent d) have a full set of complementary alleles on the Y chromosome

b) are called x-linked genes

a heterozygous female harboring one mutant allele for hemophilia is called a(n) ___ for that trait a) harborer b) carrier c) messenger d) contributor e) affected female

b) carrier

mammals are ____ and produce ___ gametes a) diploid; diploid b) diploid; haploid c) haploid; haploid d) haploid; diploid

b) diploid; haploid

harmful mutations are always quickly weeded out of a population a) true b) false

b) false

physical exchange between homologous chromosomes (crossover) occurs during metaphase 1 of meiosis a) true b) false

b) false

somatic mutations are important to the evolutionary process; most cancers result from somatic mutations a) true b) false

b) false

Which of the statements is true of incomplete penetrance? a) Incomplete penetrance refers to cases in which individuals developing a particular disease (e.g., cancer or Alzheimer's) lack the typical genotype for this disease. b) for genes with incomplete penetrance, some individuals can show the trait while others with the same genotype may not c) environmental factors do not influence penetrance d) incomplete penetrance implies that some individuals will experience less severe forms of disease such as cancer or Alzheimer's

b) for genes with incomplete penetrance, some individuals can show the trait while others with the same genotype may not

which of the statements are true of both first-and second division nondisjunction? select all that apply a) homologous chromosomes fail to separate b) gametes are produced with extra chromosomes c) sister chromatids fail to separate d) half of the gametes produced are wild-type, whereas half are mutated e) gametes are produced with missing chromosomes

b) gametes are produced with extra chromosomes e) gametes are produced with missing chromosomes

the number of new mutations in genomes following a round of genome replication: a) generally decreases with larger genomes b) generally increases with larger genomes c) is highest in bacteria d) none of the answers are correct e) is similar independent of genome size

b) generally increases with larger genomes

Homologous chromosomes separate from each other in: a) mitosis b) meiosis 1 c) they never separate from each other during any form of cell division d) meiosis 2

b) meiosis 1

Consider a gene with n alleles A1, A2, ..., An. How many distinct heterozygous genotypes are possible? a) n(n-1) b) n(n-1)/2 c) n(n+1)/2 d) n^2 e) n^2/2

b) n(n-1)/2

Sometimes homologous chromosomes fail to separate normally during meiosis I, a process called: a) unijunction b) nondisjunction c) chromosome separation d) nontransference e) conjugation

b) nondisjunction

Which of the choices is an accurate statement that accounts for why women with the genotype XXX are not phenotypically different from an XX female? a) the extra X chromosome only becomes active in nonreproductive areas of the body b) only one x chromosome is active in each cell, regardless of how many X chromosomes there are in a cell c) The X chromosome only carries genes dealing with being a female, so having another one doesnt matter d) Cells normally have enzymes that recognize and degrade extra X chromosomes e) None of the answer options is correct

b) only one x chromosome is active in each cell, regardless of how many X chromosomes there are in a cell

mutations that destroy or create a cleavage site for a restriction enzyme are the source of : a) variable number tandem repeats b) restriction fragment length polymorphisms c) SNPs d) copy number variants

b) restriction fragment length polymorphisms

genes that are close together in the same chromosome a) usually assort independently, but very rarely will be transmitted together b) tend to be transmitted together c) tend to be transmitted together and are present only in X chromosomes d) are present only in the X chromosome e) tend to assort independently

b) tend to be transmitted together

the use of the multiplication rule requires which option a) the events being considered are associated b) the events being considered occur independently

b) the events being considered occur independently

which of the statements is true about gametes? a) they have the same number of chromosomes as a somatic cell of the same individual b) they fuse to form a new organism during fertilization c) they are formed by mitotic cell division d) they are genetically identical to other gametes formed during meiosis e) they are found in animals but not plants

b) they fuse to form a new organism during fertilization

After doing PCR on the same region between two individuals, you notice that each person's DNA yielded pieces of different sizes. Which of the following is the MOST likely explanation? a) a mistake was made during the PCR b) this is an example of VNTRs c) This is an example of RFLPs d) None of the answer options is correct e) A mistake was made during gel electrophoresis

b) this is an example of VNTRs

Genotype-by-environment interaction means that genetic and environmental influences may interact or contribute to the phenotypic outcomes in unpredictable ways. a) false b) true

b) true

Organisms with the genotypes AaBBCcDdEeff and AaBBCcddEeff are crossed. Assuming independent segregation and complete dominance for each trait, what is the expected proportion of the progeny that will be homozygous for all of the genes? a) 0 b) 1/4 c) 1/16 d) 1/8 e) 9/16

c) 1/16

Given equal probabilities of the birth of an XY offspring or an XX offspring, what is the probability that a group of four siblings includes all XY offspring? All XX offspring? All XY offspring or all XX offspring? a) 1/8; 1/16; 3/8 b) 1/16; 1/8; 3/8 c) 1/16; 1/16; 1/8 d) 1/16; 1/16; 1/64

c) 1/16; 1/16; 1/8

A true-breeding black rabbit is crossed with a true-breeding white rabbit to produce an F1 generation of 16 individuals. If the black color trait is dominant, which of the outcomes represents the expected phenotype(s) of offspring from this cross? a) 0 black rabbits, 16 white rabbits, 0 gray rabbits b) 0 black rabbits, 0 white rabbits, 16 gray rabbits c) 16 black rabbits, 0 white rabbits, 0 gray rabbits d) 9 black rabbits, 3 white rabbits, 3 gray rabbits, and 1 spotted rabbit e) 5 black rabbits, 4 white rabbits, 7 gray rabbits

c) 16 black rabbits, 0 white rabbits, 0 gray rabbits

In the F2 generation of a homozygous round (AA) × homozygous wrinkled (aa) cross in peas, two seeds are chosen at random. What is the probability that one is round and the other is wrinkled? a) (1/4)^2 b) (3/4) x (1/4) c) 2 x (3/4) x (1/4) d) (3/4)^2

c) 2 x (3/4) x (1/4)

diploid somatic cells of elephants have 56 chromosomes. if nondisjunction of one of an elephant's chromosomes occurs in meiosis 2, the resulting sperm are expected to have the chromosome complement a) 56, 56, 57, 55 b) 29, 29, 28, 28 c) 28, 28, 29, 27 d) 28, 28, 28, 28 e) 29, 29, 27, 27

c) 28, 28, 29, 27

the maximum frequency of recombination between two genes is a) 100% b) 75% c) 50% d) 25% e) 0%

c) 50%

Flower color in snapdragons is due to a gene with incomplete dominance: CRCR plants have red flowers, CRCW have pink flowers, and CWCW plants have white flowers. Which cross is expected to yield progeny that all have pink flowers? a) CRCW x CWCW b) CWCW x CWCW c) CRCR x CWCW d) CRCW x CRCW e) CRCR x CRCW

c) CRCR x CWCW

if you crossed two heterozygous yellow-seed pea plants (genotypes Aa), the relative frequency of: a) the homozygous yellow seed plants (genotype AA) would be 1/4 b) green-seed plants (genotype aa) would be 1/4 c) all of these choices are correct d) the A allele in each parent's gametes would be 1/2 e) the a allele in each parent's gametes would be 1/2

c) all of these choices are correct

the principle of independent assortment states that: a) when gametes are formed, the 2 members of a gene pair will separate equally into gametes b) when gametes are formed, the 2 members of a gene pair assort together in gametes c) alleles of a gene pair assort independently of other gene pairs d) one set of alleles of a gene pair always assorts with the alleles of another gene pair

c) alleles of a gene pair assort independently of other gene pairs

Genes in different chromosomes _____ during meiosis. Genes that are very close together in the same chromosome are _____. a) do not assort independently; linked b) do not assort independently; unrelated c) assort independently; linked d) assort independently; unrelated

c) assort independently; linked

Huntington's disease is a devastating neurological disorder. If a child of an affected parent receives one copy of the Huntington allele, he or she will develop Huntington's disease. Thus, Huntington's disease is considered a _____ trait. a) reciprocal b) neutral c) dominant d) recessive

c) dominant

You are examining a human pedigree for a trait. You notice that the trait appears in every generation, is equally likely to occur in males and females, and about half of the offspring are affected when one parent is affected. The trait is most likely: a) one that shows incomplete penetrance b) produced by multiple alleles c) dominant. d) epistatic e) recessive.

c) dominant

a testcross involves crossing with a(n) ____ individual and is used to determine the ____ of the tested parent a) F2 offspring; parental genotype b) homozygous dominant; phenotype c) homozygous recessive; genotype d) homozygous recessive; phenotype e) homozygous dominant; genotype

c) homozygous recessive; genotype

the definition of mutation is "any heritable change in the genetic material." The qualifier "heritable" is necessary because: a) changes in the genetic material occur without regard for the needs of the organism. b) most changes in the genetic material are harmful to the organism. c) most changes in the genetic material are repaired soon after they occur. d) changes in the genetic material occur at random along the genome

c) most changes in the genetic material are repaired soon after they occur

Nondisjunction results in gametes that violate which principle? a) independent assortment b) dominance c) segregation

c) segregation

which of the statements concerning cancer and mutations is correct? a) none of the answer options is correct b) cancer can only occur with a mutation in a germ cell c) usually multiple mutations are required in different genes to cause cancer d) cancer can only occur with a mutation in a somatic cell e) usually a single mutation is all that is required to cause cancer

c) usually multiple mutations are required in different genes to cause cancer

Among the progeny of a heterozygous round (Aa) x homozygous wrinkled (aa) testcross, three seeds are chosen at random. What is the probability that all three seeds are round? a) 2(1/2)^3 b) 3(1/2)^3 c) 4(1/2)^3 d) (1/2)^3

d) (1/2)^3

In genetics, the dash symbol (-) is a "wild card" that stands for either the dominant allele or the recessive allele; for example, A- means the individual has either the genotype AA or Aa. Two genes that undergo independent assortment affect the shape of the seed capsule in the broadleaf weed known as shepherd's purse. Each gene has two alleles, one of which is dominant for the shape of the seed capsule. Genotypes of the form A- B-, A- bb, and aa B- have triangular seed capsules, whereas the seed capsules of aa bb genotypes are ovoid. What ratio of triangular : ovoid is expected from the cross Aa Bb x Aa Bb? a) 9:7 b) 12:4 c) 13:3 d) 15:1 e) 10:6

d) 15:1

consider a gene with four alleles: A1, A2, A3, and A4. In the cross A1A2 x A3A3, how many offspring genotypes are possible? a) 4 b) 3 c) 5 d) 2 e) 6

d) 2

For a single nucleotide polymorphism with 3 alleles, how many different diploid genotypes are possible? a) 3 b) 7 c) 5 d) 6 e) 4

d) 6

Consider an A - T versus G - C single-nucleotide polymorphism (SNP) in the human genome. This means that the DNA molecules in the population at this site have which combinations of base pairs? a) A-T or A-C or G-T or G-C b) A-T or G-T or G-C c) A-T or A-G or G-C d) A-T or G-C e) A-C or G-T

d) A-T or G-C

the difference between a SNP and a point mutation is that: a) A SNP can be corrected by various repair mechanisms, whereas a point mutation cannot b) a point mutation becomes permanently incorporated into the genome, whereas a SNP does not c) a point mutation can be corrected by various repair mechanisms, whereas a SNP cannot d) a point mutation is when a base pair is changed to a different base pair, whereas a SNP is when the base pair differs among individuals in a population. e) a SNP becomes permanently incorporated into the genome whereas a point mutation does not.

d) a point mutation is when a base pair is changed to a different base pair, whereas a SNP is when the base pair differs among individuals in a population.

sunlight exposure has stronger effect on skin cancer risk in fair-skinned humans than in individuals with darker skin. this could be an example of: a) pleiotropy b) genotype by environment interaction c) differences in the norm of reaction d) all of these are correct e) epistasis

d) all of these are correct

in genetic crosses, the symbol Aa refers to a: a) phenotype b) holotype c) morphotype d) genotype e) archetype

d) genotype

when heritability is 0%, genes play: a) a role in the expression of a trait but only a small one b) no role in the expression of a trait c) a role in variation in the trait among individuals; but it cannot be measured d) no role in variation in the trait among individuals e) a role in the expression of a trait, but it cannot be measured

d) no role in variation in the trait among individuals

A researcher is creating pedigrees for a trait he suspects to be dominant in humans. What are some of the likely features of his pedigrees for families with this trait? a) all of the offspring of a mating where 1 parent has the trait will themselves be affected b) the occurrence of mating between individuals with this trait will be high, as all dominant traits are common within any given population c) only females will have this dominant trait d) none of the other answer options is correct

d) none of the other answer options is correct

While doing a pedigree analysis of a European royal family, you notice a disease in a female child of two healthy parents. There are also some cousins with the same genetic disease. If this disease is controlled by a single gene, then the most likely explanation for these observations is the disease is: a) dominant and is seen in homozygous dominant or heterozygous individuals b) only seen in heterozygous individuals such as the daughter c) a spontaneous mutation d) recessive and only seen in homozygous recessive individuals such as the daughter e) dominant and only seen in homozygous dominant individuals such as the daughter

d) recessive and only seen in homozygous recessive individuals such as the daughter

Imagine that a doctor sees a patient that is genotypically male, but is phenotypically female. How could this occur? a) this patient likely carries a mutation in SRY that increases SRY protein levels b) This patient likely carries a mutation in SRY that increases SRY protein levels, and a mutation in the X chromosome that decreases X chromosome-associated protein levels. c) This patient likely carries a mutation in the X chromosome that increases X chromosome-associated protein levels. d) this patient likely carries a mutation in SRY that decreases SRY protein levels e) This patient likely carries a mutation in the X chromosome that decreases X chromosome-associated protein levels

d) this patient likely carries a mutation in SRY that decreases SRY protein levels

Diploid somatic cells of elephants have 56 chromosomes. If nondisjunction of one of an elephant's chromosomes occurs in meiosis I, the resulting sperm are expected to have the chromosome complement: a) 29, 29, 28, 28 b) 28, 28, 28, 28 c) 56, 56, 57, 55 d) 28, 28, 29, 27 e) 29, 29, 27, 27

e) 29, 29, 27, 27

Which of the answer choices is a possible human genotype that could result from nondisjunction of the sex chromosomes in one of the parental gametes? a) XYY b) XX c) XO d) XXY e) All of these choices are correct

e) All of these choices are correct

Which of the answer choices is true of a cross involving a sex-linked gene (one on the X or Y chromosome) but not of a cross involving an autosomal gene? a) only autosomal genes observe the law of segregation b) recombination, or crossing over, cannot take place between the X and Y chromosomes c) A Punnett square cannot be utilized for illustrating the possible outcomes of a cross involving a sex-linked gene d) Both parents have two copies of a sex-linked gene e) The phenotype outcomes of XX offspring and XY offspring can be different

e) The phenotype outcomes of XX offspring and XY offspring can be different

The Y-linked trait of hairy ears has been passed down for many generations in a certain family. A hairy-eared male in this family would be expected to have: a) nephews with hairy ears b) male and female grandchildren with hairy ears c) uncles with hairy ears d) a maternal grandfather with hairy ears e) a paternal grandfather with hairy ears

e) a paternal grandfather with hairy ears

when one gene is able to modify the effect of a second gene, the phenomenon is known as a) simple dominance b) independent assortment c) segregation d) excessiveness e) epistasis

e) epistasis

What is a single-nucleotide polymorphism (SNP)? a) a site where RNA polymerase binds to DNA b) the presence of single-nuceotides in the DNA double helix c) the site where a restriction enzyme makes a cut d) any point mutation e) the difference between 2 sequences at a single nucleotide position in a DNA sequence

e) the difference between 2 sequences at a single nucleotide position in a DNA sequence

a chromosomal segment that breaks off and attaches to another chromosome is what type of mutation? a) reciprocal translocation b) duplication c) inversion d) deletion e) translocation

e) translocation

First-division nondisjunction will only yield gametes with an extra chromosome, whereas second-division nondisjunction will only yield gametes missing a chromosome. a) true b) false

false

TRUE OR FALSE: All organisms have either an X or Y chromosome, as these chromosomes are solely responsible for determining the sex of an individual.

false

TRUE OR FALSE: An example of regression toward the mean occurs if the offspring of two short parents had an average height equal to the average height of the parents, not of the population as a whole.

false

TRUE OR FALSE: An individual is heterozygous for two linked genes, but whether its genotype is AB/ab or Ab/aB is not known. The individual is crossed with an ab/ab individual, and among the progeny are: 16 AB/ab; 54 Ab/ab; 46 aB/ab; 24 ab/ab.These results imply that the genotype of the doubly heterozygous parent was AB/ab.

false

TRUE OR FALSE: During meiosis in female mammals, sex chromosomes segregate to produce two types of eggs: X-bearing eggs and Y-bearing eggs.

false

TRUE OR FALSE: Similar to single gene traits, traits determined by multiple genes also show the expected 3:1 ratio of phenotypes in the progeny between two heterozygotes.

false

TRUE OR FALSE: The hardy-Weinberg equation will always give you the actual genotype frequencies of a population if you are given its allele frequencies

false

TRUE OR FALSE: A complex trait can be influenced by the environment.

true

TRUE OR FALSE: Genetic variations in DNA sequences in human populations, such as single nucleotide polymorphisms (SNPs), have been used to map "disease genes" by determining whether the SNP is linked to the mutant gene.

true

TRUE OR FALSE: Genotype-by-environment interaction means that genetic and environmental influences may interact or contribute to the phenotypic outcomes in unpredictable ways.

true

TRUE OR FALSE: Homologous chromosomes usually have the same arrangement of genes along their length.

true

TRUE OR FALSE: The tips of the arms of the X and Y chromosomes share small regions of homology. Genes located in these regions are inherited in the same manner as the ones found in autosomes.

true

TRUE OR FALSE: Without the SRY gene, humans and other mammals would develop and retain the female sex organs and phenotype.

true

TRUE OR FALSE: a point mutation occurs when a single nucleotide gets replaced by a different one

true

TRUE OR FALSE: a trait with high heritability responds strongly to selection, whereas a trait with low heritability responds slowly or not at all

true

TRUE OR FALSE: most of the genetic variation seen in the human population is neutral

true

TRUE OR FALSE: the genotype of a fetus can be screened for SNPs associated with some diseases

true

TRUE OR FALSE: if a population has low genetic variation, it is more susceptible to genetic drift

true (genetic drift usually decreases genetic variation)