ECOL 320
What is genomic imprinting?
A form of epigenetic inheritance in which a segment of DNA is marked in a way that it alters gene expression
Which of the following best describes asexual reproduction?
A mother cell divides to produce two identical daughter cells
In which of the following crosses would the offspring be called hybrids?
A pea plant with yellow seeds crossed to a pea plant with green seeds
A pea plant will have green pods if it has a least one green allele in its genome. A plant will have yellow pods only if it has two alleles for the yellow phenotype. What conclusions can be drawn based on this information?
A plant that has a green allele and yellow allele will have green pods. Yellow pods are recessive to green pods.
Which of these best describes a clone?
A population of cells derived from a single cell
Which of the following are correct descriptions of a gene?
A segment of DNA that influences one or more traits of an organism A unit of heredity A segment of DNA that produces a functional product
What is the F factor that is found in F+ donor strains of E. coli?
A small circular segment of DNA that is separate from the circular chromosome
What is a model organism?
An organism that is studied so that researchers can determine broadly applicable scientific principles
When does nondisjunction typically occur (choose all that apply)?
Anaphase of meiosis I Anaphase of meiosis II
______ is the gain or loss of individual chromosomes to or from a complete set.
Aneuploidy
The haplodiploid system of sex determination is used by which of the following?
Ants Bees
DNA can adopt two different conformations. Which is the most abundant conformation seen in living cells?
B DNA
What is a competent cell?
A bacterial cell that can take up foreign DNA
Which of the following is an example of a testcross in Drosophila melanogaster?
A cross between a white-eyed male and a red-eyed female
What are the main structural differences between RNA and DNA?
RNA uses ribose as a sugar; DNA uses deoxyribose RNA contains uracil; DNA does not contain uracil RNA is usually single-stranded; DNA is usually double-stranded
Suppose that the covering on corn kernels can have a purple color due to the dominant allele P of gene 1. Alleles of gene 2 can mask this color, with the dominant allele C having no effect but genotype cc changing the purple color to colorless. For corn with the genotype Ppcc, what is the effect of gene 2 on gene 1? Multiple choice question.
Recessive epistasis
A _____ translocation occurs when two nonhomologous acrocentric chromosomes lose their short arms and fuse to form a large single chromosome.
Robertsonian
In a series of dihybrid crosses, pea plants with round, green seeds were crossed to plants with wrinkled, yellow seeds. All of the progeny had round, yellow seeds. What conclusions can be drawn from this data?
Round is dominant to wrinkled and yellow is dominant to green
In 1928, Frederick Griffith did a number of experiments to identify the "transforming principle". Notably, he found that when living ______-type Streptococcus pneumoniae bacteria were injected into mice, they died. Also, he showed that when living ______-type Streptococcus pneumoniae were mixed with heat-treated smooth-type Streptococcus pneumoniae and injected into mice, the mice _____.
S R died
For dog coat color, the dominant S+ allele results in full pigmentation while the recessive si allele leads to white patches on the legs and belly called Irish spotting. Suppose that a cross between a fully-pigmented female and an Irish-spotted male yields some puppies with the mother's phenotype and others with the father's phenotype. What is the genotype of the fully-pigmented female parent in this cross?
S+si
Prader-Willi syndrome is associated with the imprinting of a gene encoding a splicing factor called ______.
SNRPN
Which is the inheritance pattern where an allele is dominant in one sex and recessive in the opposite sex?
Sex-influenced inheritance
What process involves the fusion of gametes in fertilization to produce a new organism?
Sexual reproduction
Select all of these that are true of genes that follow a Mendelian inheritance pattern.
The genes are transmissible from generation to generation. The genes segregate during gamete formation. The genes segregate independently. Expression of genes in the offspring directly influences their traits.
Which statements regarding nucleoid structure of mitochondria and chloroplasts are true?
The genome is a circular. The genome consists of double-stranded DNA. There may be more than one nucleoid per organelle. There may be more than one chromosome in the nucleoid.
The behavior of chromosomes during meiosis explains Mendel's law of segregation. Specifically, a gamete contains only one copy of each type of chromosome because of which of the following?
The homologs segregate during meiosis I and the sister chromatids separate during meiosis II
What is heterosis?
The increased vigor observed in the offspring of a cross between two different inbred lines
A male parent has the genotype TT and a female parent has the genotype Tt. How would the Punnett square for this cross be set up?
The male gametes T and T would be placed as the header of the columns and the female gametes T and t would be placed as the headers of the rows
Select all of these that are events of telophase I of meiosis.
The nuclear membrane reforms in most species Homologues have reached their respective poles
What is the fundamental repeating structural unit of DNA and RNA?
The nucleotide
inversions are classified based on what characteristic?
The position of the centromere
Congenital analgesia is a rare autosomal recessive trait. What is the likelihood that the first two offspring of a cross between two unaffected parents heterozygous for the congenital analgesia trait will have congenital analgesia?
The probability of heterozygous parents having a child with congenital analgesia is 1/4 for each pregnancy. 1414 x 1414 = 116116 or 6.25%
What is the focus of population genetics?
The relationship between genetic variation and an organism's environment
What is the focus of the biometric field of genetics?
The statistical study of biological traits
What was the purpose of the experiments of Avery, MacLeod, and McCarty?
To determine the nature of the transforming principle and thus the nature of the genetic material
What is horizontal gene transfer?
Transfer of DNA to a recipient that is not the offspring of the donor organism
Which of the following statements about transformation is correct?
Transformation is a natural process that has evolved in some species of bacteria.
Which of the following would be classified as the P generation?
True-breeding parents that are crossed
What does a phosphodiester bond link together?
Two sugars on adjacent nucleotides in DNA or RNA
A deletion of a region of chromosome 15 that includes the gene ______ has been shown to cause Angelman syndrome.
UBE3A
For Angelman syndrome, which gene is lacking in expression?
UBE3A
Match each pedigree symbol with the correct description.
Unfilled circle= Unaffected female Filled circle= Affected female Half filled circle= Heterozygous female Circle with a line through it= Deceased female
There are several cellular processes that involve the formation of double-stranded RNA. When double-stranded RNA forms, the base A can hydrogen bond with the base ___, and the base C can base pair with the base ___
Uracil (U) Guanine (G)
Which component of genetic variance is attributed to alleles that have additive effects?
V(A)
Genetic variance can be partitioned into three distinct categories. Match each type of variance with the correct description.
VA= variance due to the additive effects of alleles VD= variance due to the effects of alleles that follow a dominant/recessive pattern of inheritance VI= variance due to the effects of alleles with epistatic interactions
The phenotypic variance of a quantitative trait can be partitioned into several components. Match each component of variation to the correct description.
VG= Genetic variance VE= Environmental variance V(G X E)= Variance due to interactions between genetic and environmental factors V(G←→E)= Variance due to associations between genetic and environmental factors
What proportion of inversions cause phenotypic consequences?
Very few of them
Which two scientists independently proposed the chromosome theory of inheritance?
Walter Sutton Theodore Boveri
Who proposed the idea that a chemical substance was responsible for the transmission of information between cells and between generations?
Weismann Nageli
To conduct a chi square analysis to discriminate between linkage and independent assortment in a cross, a scientist needs
a hypothesis. the expected number of offspring based on a Punnett square. the observed number of offspring.
A hypothesis used to predict results that are consistent with the laws of inheritance is called ______.
a null hypothesis
A tall pea plant with axial flowers has the genotype TTAA. What are the gamete possibilities of this plant?
all TA
Trisomy X typically does not cause phenotypic abnormalities because ______.
all additional X chromosomes are converted to Barr bodies
If the heritability value of a trait is equal to 1, it means that ______.
all of the phenotypic variation in the population is due to genetic variance
An alternative form of a gene is called a(n)
allele
Alternative versions of the same gene are called
alleles
Two plants each have a gene that determines pea pod color. In one plant, this gene produces yellow pea pods. In the other plant, this gene produces green pea pods. What are these variations of pea pod genes called?
alleles
The term ______ variation refers to differences in specific genes.
allelic
A scientist conducting an interrupted mating experiment can increase the amount of the Hfr chromosome that is transferred by ______.
allowing conjugation to proceed for a longer period of time
The genetic code directs the order of ______ within a polypeptide based on the sequence of nucleotides within a DNA molecule.
amino acids
Crossovers produce recombinant chromosomes through ______.
an exchange of chromosomal segments between homologous chromosomes
Aneuploidy causes an abnormal phenotype due to ______.
an imbalance of gene products
The regulation of a genomic imprint involves ______ near the imprinted gene.
an imprinting control region
The ______ stage of meiosis I is characterized by the separation of the two pairs of sister chromatids within a bivalent from each other and their migration to opposite poles of the cell.
anaphase
When phenotypic variance is determined solely by genotypic and environmental variance, and genetic and environmental factors are independent of one another, then total phenotypic variance is equal to genetic variance ___ environmental variance.
and
Changes in the number of individual chromosomes such that the total number of chromosomes is not an exact multiple of a set results in a condition called ___
aneuploid
When one strand of DNA in a double helix has the chemical polarity 5' to 3', and the other, running in the opposite direction, has the chemical polarity 3' to 5', then it would be said that the two strands are ___
antiparallel
When two strands of DNA in a double helix run in opposite directions, one 5' to 3' and the other 3' to 5', what is this called?
antiparallel
If a correlation coefficient of two traits is negative, it means that _____.
as one trait increases, the other decreases
Unicellular prokaryotic organisms proliferate by ________ reproduction, in which a preexisting cell divides to produce two new cells.
asexual
A dominant trait predicts that affected individuals will have inherited the gene from ______.
at least one parent
An individual that has multiple sets of chromosomes from the same species is best described as a(n) ______.
autopolyploid
A human cell contains two main types of chromosomes: sex chromosomes and ______
autosomes
Chromosomes that are not sex chromosomes are called
autosomes
What substance needs to meet the following criteria: ability to contain the information necessary to construct an entire organism; ability to be passed from parents to offspring; ability to be replicated; contains variation?
genetic material
Any process in which one bacterium transfers genetic material to another bacterium is called ______.
genetic transfer
The term that describes all of the DNA found in all of an organism's chromosomes is
genome
Extranuclear genes are not segregated into gametes the same way the nuclear chromosomes are. As such, extranuclear genes ______ exhibit Mendelian patterns of inheritance.
do not
A trait that is expressed with either one or two of the same alleles is ______.
dominant
Despite the fact that human males are XY and human females are XX, they have equal expression of many genes on their sex chromosomes. This phenomenon is called ______
dosage compensation
Which of the following cells are gametes?
egg sperm
What pattern of inheritance does this pedigree suggest?
either dominant or recessive because all affected individuals have at least one affected parent
A diploid organism that has some polyploid cells is exhibiting ___
endopolyploidy
Liver cells of humans may be triploid (3n), tetraploid (4n), or even octaploid (8n). This phenomenon is best described as ______.
endopolyploidy
The theory that explains the evolution of some eukaryotic organelles such as chloroplasts and mitochondria is called the _____ theory.
endosymbiosis
An organism's traits can be affected by its genes and also by its
environment (surroundings)
A pattern of inheritance in which a temporary alteration to a chromosome modifies gene expression but is not permanent over many generations is called _______ inheritance.
epigenetic
For summer squash, the dominant allele for one gene leads to yellow color while the recessive allele for this gene leads to green color. When the genotype of a second gene is either homozygous dominant or heterozygous, neither color is produced and the squash is white. The effect of the second gene on the first one is called ______.
epistasis
A gene that codes for a product that is necessary for the survival of an organism is called a(n) ______ gene.
essential
A(n) _____ organism is one with a chromosome number that is an exact multiple of a chromosome set.
euploid
In a particular plant species, individuals can be diploid, triploid, or tetraploid. All of these organisms are said to be ______.
euploid
Changes in the genetic makeup of a population from one generation to the next represent
evolution or microevolution
In a form of epigenetic inheritance called _________, a segment of nuclear DNA is marked in a non-permanent way that alters gene expression throughout the life of the individual.
genomic imprinting
When performing a chi-square test to distinguish between linkage and independent assortment in a two-factor cross, a scientist must take into account the observed and ______ values for each of the four phenotypes in the cross.
expected
The process of using a gene sequence to affect the characteristics of cells and organisms is called gene ______.
expression
The type of inheritance that occurs because extranuclear genes are inherited through the cytoplasm of an egg is called ________
extranuclear inheritance
An organelle such as a mitochondrion or a chloroplast will only have one nucleoid.
false
Transformation, the uptake of foreign DNA by bacterial cells, does not occur in nature, but it is possible in genetically engineered bacterial strains.
false
True or false: Epigenetic changes to a chromosome are permanent modifications that remain over the lifetime and later generations of the organism.
false
When a chi-square test shows that the correlation coefficient for two variables is statistically significant, it means that there is a cause-and-effect relationship between the variables.
false
A collection of two or more genes in a particular species that are similar to each other is known as a gene ______
family
In humans with a typical constitution of chromosomes, X-chromosome inactivation induces dosage compensation by randomly inactivating one of the X chromosomes in the somatic cells of ______.
females
In a three-factor cross, rather than create a large Punnett square, one can calculate expected outcomes using the multiplication method and the _______-line method.
forked
A patient with sickle cell disease may experience a painful episode leading to tissue and organ damage because cells carrying hemoglobin S ______.
form abnormal crescent shapes that block capillaries, depriving nearby cells of oxygen
The eukaryotic cell cycle is composed of ______ phases called ______.
four; G1, G2, S, and M
A graph that presents phenotypic categories on the x-axis and the number of individuals that fall into a category on the y-axis is called a(n) ___ distribution.
frequency
The type of mutation that leads to increased expression of an altered protein in a cell which does not normally express the protein is called a ____________ mutation.
gain-of-function
The Antennapedia mutation causes fruit flies to develop legs in the places on their heads where antenna would normally be found. Expression of the Antennapedia gene product in a location where it is not usually active is due to a ______ mutation for a ______ mutant allele.
gain-of-function; dominant
Sperm and egg cells are also called
gametes
Sexual reproduction involves the fusion of two ______ in the process of ______.
gametes ; fertilization
The life cycles of plant species alternate between haploid and diploid generations. The haploid generation is called the _____, whereas the diploid generation is called the ____
gametophyte sporophyte
The functional unit of a chromosome is called a ___
gene
Corn kernels can have a purple color due to the dominant allele of one gene. When the alleles of a second gene are present in the homozygous recessive genotype, the kernel color is changed to red. This is an example of ______.
gene interaction
The pattern where allelic variants of two different genes affect a single trait is called ____?
gene interaction
When a geneticist produces an organism that is homozygous for a loss-of-function allele, the change is called a(n) ____?
gene knockout
The term to describe the basic unit of heredity that influences an organism's traits is a(n) .
gene or allele
Compared to two-factor testcrosses, three-factor testcrosses can provide additional information about ______.
gene order map distance
Mendel studied many morphological characteristics such as pea pod color, flower color and plant height. Today, these "characters" that Mendel studied are known to be influenced by units of heredity called ______.
genes
The result of a two-factor cross depends on whether the ____ are linked together on the same ____
genes chromosome
Paralogs are homologous ____
genes within the same species
A diagram that shows the order of genes occurring on the same chromosome is called a(n) ______ map.
genetic
Most genes contain the information to direct the synthesis of a polypeptide. The order of amino acids in the polypeptide is specified according to the _____ code.
genetic
When a quantitative trait is analyzed, its phenotypic variance can be partitioned into ___ variance, ___ variance, and the interactions and associations between them.
genetic environmental
The linear arrangement of genes on a chromosome is depicted on a _____ map.
genetic linkage
The phenomenon in which genes that are close together on the same chromosome tend to be transmitted as a unit is _____
genetic linkage
What is the name of the phenomenon in which genes located together on a chromosome are usually transmitted together?
genetic linkage
A ______ is a diagram that identifies the order of genes along a chromosome.
genetic map
The genetic composition of an individual is the ______. describes the combination of alleles an individual has.
genotype
DNA sequences with a high proportion of base-pairs between ___ and ___ are most stable.
guanine (G) cytosine (C)
A bacterium is typically _____ for a particular gene, meaning that it only has one copy of the gene.
haploid
For a given gene, a bacterial cell is usually ______.
haploid
A cell that contains a single set of chromosomes is called
haploid or monoploid
Hemophilia is an X-linked recessive trait. In order for a female child to have hemophilia ______.
her father must have hemophilia and her mother may have hemophilia or be a carrier
Genetics is the branch of biology that deals with ______.
hereditary and variation
For a particular population in a particular environment, the fraction of phenotypic variance that is due to genetic variance is called ___
heritability
In humans, the male is known as the ____ sex, because one type of sperm carries only the X chromosome, and another type carries the Y chromosome. The female, on the other hand, is the ____ sex because all eggs carry a single X chromosome.
heterogametic homogametic
A species that produces two kinds of gametes, with unequal distribution of cytoplasmic organelles, is said to be a ______ species.
heterogamous
In _______ species, two kinds of gametes are made such that the distribution of cytoplasmic organelles is unequal in the two gamete types and organelles are often inherited from one parent.
heterogamous
When two different inbred strains are bred with one another, their offspring are often larger and/or longer-lived than either of the inbred parental strains. This phenomenon is called hybrid vigor, or ___
heterosis
An organism that has two different alleles for a single trait is ______.
heterozygous
If a diploid organism carries one purple allele and one white allele for the petal color gene their genotype would be described as ______.
heterozygous
In a three-factor cross, the goal of the first step is to obtain F1 individuals that are _____ for all three genes.
heterozygous
One form of hereditary deafness is inherited with an X-linked recessive allele. A woman with normal hearing has a son with hereditary deafness. The woman's genotype at this gene locus is ______.
heterozygous
In conducting a chi square analysis of a two factor cross, if the chi square value is ____, we reject the null hypothesis that the genes assort independently, and accept that the genes are linked.
high
A type of protein that can bind to the DNA backbone, affecting the compaction of DNA in eukaryotic cells, is a(n) ___
histone
Which proteins form ionic interactions with the negatively charged phosphates of the DNA backbone?
histones
Genes located only on the Y chromosome are called ______ genes.
holandric
Two or more genes that are derived from the same ancestral gene are referred to as ______ genes.
homologous
A fundamental principle of the chromosome theory of inheritance involves the chromosome composition of cells. Most eukaryotic cells are diploid, containing chromosomes that are found in ______ pairs. During the process of _______, the two members of each pair segregate into different daughter nuclei.
homologous meiosis
Synapsis is the process by which ______.
homologous chromosomes recognize each other and begin to align themselves in prophase I.
In a diploid organism, the two copies of a chromosome are referred to as ______.
homologs
In this figure, two copies of chromosome 13 are circled. These two copies of chromosome 13 are called _____ of each other.
homologs (homologous)
If an organism has identical alleles for a given trait it is said to be ______.
homozygous
The genotype AAbbCCdd is ______.
homozygous
The transfer of genetic material to an organism that is not the offspring of the donor organism is referred to as _____ gene transfer.
horizontal or lateral
The offspring of a genetic cross between organisms with distinctly different traits for a particular character is called a ___
hybrid or monohybrid
The process which involves the formation of a double-stranded DNA molecule from single-stranded DNA molecules of two different samples is termed _____.
hybridization
The offspring of a pea plant with purple flowers and a pea plant with white flowers would be called ______.
hybrids
One useful strategy for solving problems in genetics is to propose a(n) _____ , which is an attempt to explain an observation or data.
hypothesis
Statistical analysis cannot prove that a ____ is true.
hypothesis
Use of an objective, statistical method to evaluate whether genetic data are consistent with Mendel's laws is called ____ testing.
hypothesis
A process for determining whether data from genetic crosses are consistent with a specific pattern of inheritance is called ______.
hypothesis testing
Which approach involves implementation of the scientific method to test an explanation for a natural phenomenon?
hypothesis testing
A gene family is a set of genes ______.
in a particular species that are similar to each other
Which pattern is shown by a heterozygous individual that has a phenotype that is intermediate between the phenotypes of the dominant and recessive homozygotes?
incomplete dominance
For which of the following genotypes would the effects of codominance be observed in the individual's phenotype? Multiple choice question.
IAIB
Which of the following statements about polyploidy is true?
It is more common in plants than in animals
Which two fundamental laws of inheritance did Mendel discover?
Law of Segregation and Law of Independent Assortment
Select the two fundamental laws of inheritance discovered by Mendel.
Law of independent assortment Law of segregation
What accounts for the lack of pigment in the white flowers of the pea plants studied by Mendel?
Loss of function allele
Which of the following would provide clues to determine the role of a protein within an organism?
Loss-of-function allele
Which of the following statements about the X-Y system of sex determination is true?
Male is XY Female is XX
How many genes does a typical human chromosome contain?
Many hundreds
What type of inheritance accounts for the genotype of the mother being the direct determining factor in the phenotype of the offspring?
Maternal effect
How can nucleotides found in RNA be discriminated from those found in DNA?
RNA nucleotides may contain uracil RNA nucleotides contain ribose RNA nucleotides don't contain thymine
A tall pea plant is crossed with a different tall pea plant. What type of cross is this?
Single-factor cross
Suppose a genetic test shows that a woman has inherited the dominant BRCA1 allele that causes breast cancer. If she does not develop breast cancer in her lifetime, the phenomenon is called _____?
incomplete penetrance
The pattern observed when a heterozygote does not show the trait associated with the dominant allele is _____?
incomplete penetrance
Mendel's law of ____ suggests that a two-factor cross between two individuals heterozygous for two genes should yield a 9:3:3:1 phenotypic ratio among the offspring.
independent assortment
The random arrangement of homologs along the metaphase plate in meiosis I is consistent with Mendel's law of ____
independent assortment
When an offspring receives a combination of alleles that differs from those in the parental generation it can be due to ______.
independent assortment crossing over
Genetic variation describes differences in ______.
inherited traits among individuals within a population
A chromosomal structural change in which a segment of DNA is rotated 180o is referred to as a(n) _____
inversion
Morgan explained his data by suggesting that if two genes are far apart from each other, crossing over?
is more likely to occur than between two genes that are closer together.
In general, the chromosome number of a particular species ______.
is the same for all individuals of the species
What is the main function of a cell's genetic material?
it encodes proteins
A(n) ______ is a micrograph which displays the chromosomes of a cell, usually in descending order of size.
karyotype
An organized representation of the chromosomes of a cell is called a ______.
karyotype
During metaphase I of meiosis, one pair of chromatids in a bivalent (but not both) is attached to a ______. Therefore, each pair of sister chromatids is attached to only one pole.
kinetochore microtubule
If ______ recombination occurs at an early stage of embryonic development, the adult organism may have a patch of tissue with characteristics different from the rest of the organism.
mitotic
You discover a dog that has a patch of white hair on its side and is completely black otherwise. The patch may be the result of ______.
mitotic recombination
Which is the pattern of inheritance for holandric genes? (Y)
only transmitted from father to son
The non-Mendelian inheritance pattern observed in snail coiling is most related to ______.
oogenesis
If you constructed a ball-and-stick model of the DNA double helix, you would build the sugar-phosphate backbone so that it is oriented facing ______ and so that the bases were facing ______.
outwards; inwards
The situation where a heterozygote has a characteristic that makes it more likely than either homozygous individual to reproduce in a given environment is called _____?
overdominance
What is the name for the situation where heterozygotes have greater reproductive success than either of the two homozygotes?
overdominance
In a single species, homologous genes are called _____ and collectively make a gene family.
paralogs
In humans, trisomy 13 is also known as ______, while trisomy 18 is called ______.
patau syndrome edwards syndrome
For a human offspring to express a paternal mitochondrial gene, the individual must have inherited a mitochondrion from the sperm. This is called ______.
paternal leakage
In a species where maternal inheritance is the norm, the rare case in which mitochondria are provided by the sperm is a phenomenon called _________
paternal leakage
To determine inheritance patterns in humans, researchers use a chart called a(n) ______ that represents family relationships.
pedigree
A dog has fur that is white with black spots. Which term correctly reflects this fact?
phenotype
What term describes the outward expression or observable characteristics of a gene?
phenotype
DNA nucleotides have three main parts to their structure: at least one ______ group; a nitrogenous ______; and a 5 carbon sugar called _______
phosphate base deoxyribose/pentose
What are the three parts of a nucleotide?
phosphate group pentose sugar nitrogenous base
Hershey and Chase were able to track whether the viral DNA or the viral protein entered the host bacterium because they were able to label the viral DNA with radioactive ______ and the viral protein with radioactive ______.
phosphorus; sulfur
During conjugation, the initial contact between the donor and recipient cell involves structures called sex ____ that are made by F+ strains.
pili
Polyploidy is commonly found in species of ______.
plants
The allele for sickle cell anemia leads to multiple changes in the individual's phenotype, including the type of hemoglobin produced, the shape of red blood cells, the onset of anemia and reduced susceptibility to malaria. The name for these multiple effects on phenotype is ______.
pleiotropy
The pattern where one gene affects many traits is called ___
pleitropy
Quantitative traits tend to show a continuum of variation because they are usually ___, meaning that they are controlled by multiple genes.
polygenic
Genes are the source of products for cellular function. The product of most genes is a ______.
polypeptide
The functional product of most genes is a(n)
polypeptide (also can put protein or RNA)
A(n) ______ organism is one that contains three or more sets of chromosomes.
polyploid
The field of genetics that focuses on the relationship of genetic variation to an organism's environment is called ___ genetics.
population
A diploid cell has a pair of homologous chromosomes. One chromosome has the alleles Pq and the other chromosome has the alleles pQ. The cell undergoes meiosis. Select the recombinant cells below.
pq PQ
The product rule can be used to ______.
predict the probability of two or more independent events
The _____ allows us to calculate the likelihood of a double crossover if we know the individual likelihood of each single crossover.
product rule
The probability of two or more independent events occurring is calculated by multiplying the probability of each event. This is an example of ______.
product rule
Which operation of probability should be used to analyze genetic crosses in which the outcomes are independent of each other?
product rule
During ______ ______ of meiosis, the spindle apparatus is complete and the chromatids are attached via kinetochore microtubules.
prometaphase I
Crossing over occurs during ______ of meiosis I.
prophase
Heritability is a measurement of the ______.
proportion of phenotypic variance due to genetic variance
Bacteriophages are composed of genetic material that is surrounded by a coat made of ______
protein
The four categories of large organic molecules that are found in cells are nucleic acids, lipids, carbohydrates, and
proteins
The primary function of DNA is to code for the production of
proteins (aka polypeptides or RNA)
The complete set of proteins that a cell makes at a given time is called its
proteome
In humans, the genes for fibroblast growth factor receptor 1 and lipoprotein lipase are both on chromosome 8. Therefore these genes are ______.
syntenic
The genes located in mitochondria and chloroplasts do not exhibit Mendelian patterns of inheritance.
true
A person with 44 autosomes, one X chromosome, and no Y chromosome is said to have ___ syndrome.
turner
How many genes control hull color in bread wheat?
two
How many hydrogen bonds form between adenine and thymine, and between guanine and cytosine?
two three
Which of the following is a commonly used agent for promoting polyploidy?
Colchicine
How long is a single turn of the DNA double-helix?
3.4 nm
Sex chromosomes are chromosomes that determine sex in all species.
False (many different species not all)
What is the function of the sex pili during conjugation?
They make contact with recipient cells.
The unit of measure that is used for the distance between two genes on a bacterial chromosome is the ______
minutes
Crossing-over during ______ occurs much less frequently than crossing-over during ______.
mitosis; meiosis
Self-fertilization is a cross in which ______.
the pollen and egg come from the same plant
In pea plants the allele for axial flowers (A) is dominant to the allele for terminal flowers (a). What is the expected genotypic ratio of a cross between two pea plants that are heterozygous for the axial flower gene?
1 AA : 2 Aa : 1 aa
Based on Mendel's law of independent assortment, an organism with the genotype AaBb should form gametes with which of the following ratios?
1 AB : 1 Ab : 1 aB : 1 ab
Copy number variation (CNV) describes DNA segments of at least ______ in size which exhibit copy number differences among members of ______.
1,000 bp ; the same species
What are the gamete possibilities of an organism with the genotype Tt?
1/2 T and 1/2 t
The structure of DNA that Crick and Watson proposed has ___ (number) strands of DNA that are wrapped around each other to form a double helix. The DNA bases of each strand of DNA point towards the central axis of the molecule and are held together by ___ bonds.
2 hydrogen
in distinguishing between linkage and independent assortment, the chi-square equation calculates the sum of ______ for each class.
(O-E)2/E
A chromosome contains three genes in the following order: a - b - c. The distance between gene a and b is 5 mu. The distance between b and c is 3 mu. What is the expected likelihood of a double crossover?
.0015
In a certain type of plant, the phenotypic variance for height is 10 cm2. VE = 6 cm2, VG = 4 cm2, and VA = 2 cm2. What is the narrow-sense heritability for this trait?
.2
In a population of chickens, the phenotypic variance for egg weight is 20 g2. VE = 8 g2, VG = 12 g2, and VA = 5 g2. What is the narrow-sense heritability of egg weight in this population of chickens?
.25
In a population of dairy cows, the phenotypic variance for daily milk production is 5.0 L2. The genetic variance is 2.0 L2, and the environmental variance is 3.0 L2. What is the broad-sense heritability for daily milk production in this group of cattle?
.4
A female with Turner syndrome (XO) would have how many Barr bodies in her cells?
0
If all of the phenotypic variation for a trait is due to environmental effects, not to genetic variation in the population, then the heritability of the trait will be equal to ______.
0
Presence of freckles (FF or Ff) is dominant to lack of freckles (ff). If a heterozygous male, who has freckles, mates with a female that does not have freckles, what percentage of the F1 generation would be expected to have a homozygous dominant genotype?
0%
A Punnett square is a tool that can be used to predict the expected ratios of a genetic cross. List the following steps in the correct sequence.
1. Determine the genotype of each parent 2. List all of the gamete possibilities from each parent 3. Create a Punnet square with gametes of each parent listed (top/side) 4. Determine possible offspring genotypes by filling out the boxes 5. Analyze the relative proportion of each genotype and phenotype
List the steps that would be used to analyze a genetic cross with the chi square test.
1. Propose a hypothesis to calculate the expected value based on Mendel's laws. 2. Calculate the expected values of the phenotypes 3. Apply the chi square formula using the expected values 4. Interpret the expected chi square value using a chi square table
For dog coat color, the dominant S+ allele results in full pigmentation while the recessive si allele leads to white patches on the legs and belly called Irish spotting. Two fully-pigmented dogs have puppies with Irish spotting. What is the approximate fraction of offspring with Irish spotting expected from this cross?
1/4
A tall pea plant with axial flowers has the genotype TtAa. What are the gamete possibilities of this plant?
1/4 TA : 1/4 Ta : 1/4 tA : 1/4 ta
The probability of producing a dwarf plant from two heterozygous parents is 1414. What is the likelihood that these same parent plants will produce 3 dwarf plants?
1/4 x 1/4 x 1/4= 1/64 or 1.6%
There are two conformations of DNA: B DNA and Z DNA. What are the main structural features of B DNA?
10 base-pairs per turn Bases are aligned perpendicular to the central axis of the molecule
When analyzing genetic crosses using the laws of probability, the sum of all independent events occurring must add up to ______.
100%
In Drosophila melanogaster, 2n = 8. A triploid fly would have ______ chromosomes, while a tetraploid fly would contain ______ chromosomes.
12 ; 16
For summer squash, the dominant allele Y for gene 1 leads to yellow color while the recessive allele y leads to green color. Alleles of gene 2 can prevent color formation, with the dominant allele W leading to white squash while the recessive allele w does not interfere with color development. For the cross YyWw x YyWw, what is the fraction of offspring that will be white?
12/16
In humans, the most common disorders involving abnormalities in the number of autosomes are trisomies of chromosomes ___, ____, and ____.
13 18 21
Consider a piece of double-stranded DNA that is 2,000 base pairs in length. If this piece of DNA had a total of 600 deoxyadenosine monophosphate nucleotides, how many deoxycytidine monophosphate nucleotides would be present? [When a nucleoside triphosphate is incorporated into DNA, it loses two phosphates to form a monophosphate.]
1400 Reason: A double-stranded piece of DNA that is 2,000 base pairs in length contains 4,000 nucleoside monophosphates. A=T for double-stranded DNA, so there will be 600 deoxyadenosine and 600 deoxythymidine monophosphates for 1200 A + T. 4000-1200 gives 2,800 remaining nucleoside monophosphates that represent G + C. 2,800/2 = the amount of deoxycytidine monophosphates.
In comparison to a normal diploid cell, a cell that is trisomic would produce up to ______ of the protein product of the gene found in three copies. Therefore, an imbalance occurs between the level of expression of this gene versus the ones that are normally found in pairs.
150%
When was the structure of the DNA double-helix discovered?
1953
The structure of the DNA double-helix was discovered in the year ___
1953 or 1952
When adenine base pairs with thymine, ____ hydrogen bonds form, and when cytosine base pairs with guanine, ___ hydrogen bonds form.
2 3
Purple flower color is dominant to white flower color in pea plants. Yellow seed color is dominant to green seed color. If you cross a pea plant with purple flowers and yellow seeds that is heterozygous with a pea plant with white flowers and green seeds, what would be your expected phenotypic ratio?
25% purple flower with yellow seeds:25% purple flower with green seeds:25% white flower with yellow seeds: 25% white flower with green seeds
During mitosis of a particular diploid cell, a single chromosome undergoes nondisjunction. What will be the chromosome number in the resulting daughter cells?
2n + 1, 2n - 1
In pea plants, axial flowers are dominant to terminal flowers. What is the expected phenotypic ratio of a cross between two pea plants that are heterozygous for the axial flower gene?
3 axial; 1 terminal
If one strand of DNA has the sequence 5'-TTCCTAGATG-3', the sequence of the bases on the complementary strand of DNA would be ______.
3' AAGGATCTAC 5'
If one strand of DNA has the sequence 5'-ATGCTACATA-3', what would be the sequence of the bases on the complementary strand of DNA?
3' TACGATGTAT 5'
A single turn of the DNA double-helix has a length of ___ nm.
3.4
Suppose that the covering on corn kernels can have a purple color due to the dominant allele P of gene 1. The genotype pp leads to a colorless covering. Alleles of gene 2 can modify the purple color, with the dominant allele R having no effect but genotype rr changing the purple color to red. Alleles of gene 2 have no effect on plants with genotype pp for gene 1. For the cross PpRr x PpRr, what fraction of the plants are expected to have red covering on their corn kernels?
3/16
When Blue-Eyed Mary plants inherit at least one dominant allele B of gene 1 their petals are blue to match their name. Plants with bb genotype will have white petals. Alleles of gene 2 can modify the blue color, with the dominant allele M having no effect but the genotype mm changing the blue color to magenta. Alleles of gene 2 have no effect on plants with genotype bb for gene 1. For the cross BbMm X BbMm, what fraction of the offspring are expected to have magenta petals?
3/16
Based on Mendel's law of independent assortment, what phenotypic ratio should the offspring of a two-factor cross between two individuals heterozygous for two genes show?
9:3:3:1
What is the expected phenotypic ratio for a cross between plants of the following genotypes: RrYy x RrYy?
9:3:3:1
What is the expected phenotypic ratio when a plant that is heterozygous for two traits is allowed to self fertilize?
9:3:3:1 (dihybrid cross)
Normal somatic cells of a human have a total of ______ chromosomes, whereas those of a fruit fly contain a total of _____ chromosomes.
46 8
Consider a piece of double-stranded DNA in which each strand of the helix has 1,800 nucleotides. If the piece of double-stranded DNA had a total of exactly 600 deoxycytidine monophosphate nucleotides, how many deoxyguanosine monophosphate nucleotides would be present? [When a nucleoside triphosphate is incorporated into DNA, it loses two phosphates to form a monophosphate.]
600
In a three-factor cross, the Punnett square would have how many boxes?
64
Suppose that the covering on corn kernels can have a purple color due to the dominant allele P of gene 1. The genotype pp leads to a colorless covering. Alleles of gene 2 can mask the purple color, with the dominant allele C having no effect but genotype cc changing the purple color to colorless. Alleles of gene 2 have no effect on plants with genotype pp for gene 1. For the cross PpCc x PpCc, what fraction of the plants are expected to have colorless covering on their corn kernels?
7/16
When considering two genes on a fly chromosome, if a fly cross yields 63 recombinant offspring out of 656 total offspring, what is the distance between the two genes in question?
9.6 map units
What is a bacteriophage?
A virus that infects bacteria
Which letter denotes the F1 generation?
A- P generation B- F1 generation C- F2 generation
Which of these represents a homozygous genotype?
AA AAbb bb
Determine the possible gametes that could normally be formed from an organism with the genotype AaBb.
AB aB ab Ab
Determine the possible gametes that could normally be formed from an organism with the genotype AABbCc.
AbC Abc ABc ABC
What are the four nitrogen-containing bases found in the nucleotides that make up DNA?
Adenine Thymine Guanine Cytosine
One form of hereditary deafness is inherited with an X-linked recessive allele. What can be expected for the offspring of a deaf mother and a father with normal hearing?
All of the sons will be deaf and all of the daughters will have normal hearing.
Select all of these that are true regarding recessive inheritance.
All offspring of two affected individuals will be affected. Two heterozygotes will generally have affected offspring 25% of the time.
What is a Barr body?
An inactivated X chromosome in mammalian somatic cells
Which of the following exemplifies genetic recombination?
An offspring receives a combination of alleles that differs from those in the P generation
What are the criteria DNA must meet to fulfill its role?
Be able to be replicated Be transmissible Contain information Potential for variation
Which operation of probability should be used to analyze genetic crosses in which the problem has an unordered combination of outcomes?
Binomial Expansion
What is the name for the following formula? P = n/x!(n−x)! x pxqn-x
Binomial expansion equation
Which field of genetics involves the statistical study of biological traits?
Biometrics
Which of the following are examples of quantitative traits?
Blood pressure in humans Number of bristles in Drosophila Speed of flight in birds
Which of the following statements about synapsis and crossing over is true?
Both synapsis and crossing over occur in prophase I of meiosis
The chromosome theory of inheritance was a milestone in our understanding of genetics. It was independently proposed by Theodore ________ , a German biologist, and American geneticist Walter _____
Boveri Sutton
Which of the following represent heterozygous genotypes?
Cc BbCc
What are somatic cells?
Cells that are not involved in sexual reproduction
Which of the following statements about the life cycle of plants is true?
Certain cells in the sporophyte undergo meiosis to produce haploid cells, which divide by mitosis to produce a gametophyte.
What is evolution?
Change in the genetic makeup of a population from one generation to the next
Which operation can be used to test a hypothesis?
Chi square test
The genetic variation among individuals within a population can be explained by differences in the sequence of
DNA (aka bases)
Which type of genetic transfer requires direct physical contact between two living bacterial cells?
Conjugation
Which of the following statistical values is a measure of the relationship between two variables?
Covariance
Select the experiments/calculations that are included in using a three-factor cross to map genes.
Cross of two true-breeding fly strains Calculation of map distance Testcross
What are the reasons that the common garden pea, Pisum sativum, was an ideal species to study genetic crosses?
Cross pollination was simple due to the large flower size The Pisum sativum plants that Mendel used were true breeding with two distinct genotypes and phenotypes for specific traits The plant has distinct varieties
A gene can be described as a unit of heredity or as a segment of _____ that produces a functional product.
DNA
Adenine, thymine, guanine and cytosine are nitrogen-containing bases found in ______.
DNA
What is the genetic material of all living organisms composed of?
DNA
Nucleotides are used as the fundamental repeating structural unit of ___ and ___.
DNA RNA
What are the names of the different types of nucleic acids?
DNA RNA
Which of the following molecules are nucleic acids?
DNA RNA
Place the molecules produced when a gene is expressed in the correct sequence beginning with the gene.
DNA mRNA Protein
How can nucleotides found in DNA be discriminated from those found in RNA?
DNA nucleotides contain deoxyribose DNA nucleotides may contain thymine DNA nucleotides never contain uracil
The information in a(n) _____ molecule is stored in the sequence of its nucleotide bases.
DNA or RNA
Which of the statements below correctly describe the structure of a DNA double helix?
DNA strands form a helical structure Bases on opposite strands are hydrogen bonded together
What can affect the outcome of a cross, causing scientists to reject the independent assortment hypothesis, even though it may be correct?
Decreased viability of particular phenotypes
Copy number variations may involve which of the following?
Deletions Duplications
What underlies the majority of the genetic variation among individuals within a population?
Differences in the nucleotide sequence of DNA
What is the difference between hypothesis testing and discovery-based science?
Discovery-based science does not require a preconceived hypothesis.
What accounts for equal expression of genes on the sex chromosomes despite the fact that males and females have an unequal complement of sex chromosomes?
Dosage compensation
Comparative genomic hybridization is a method that can be used to detect what changes in chromosome structure?
Duplications Deletions
Which of the surface antigens related to blood type would be found on the red blood cells of an individual with the IAIB genotype?
Each red blood cell would carry both surface antigen A and surface antigen B.
Nondisjunction occurs during what stage of meiosis?
Either anaphase I or anaphase II
Match each stage of genomic imprinting with the correct description.
Establishment of the imprint= During gametogenesis either maternal or paternal allele is silenced and the other is expressed Maintenance of the imprint= The imprint pattern is continued throughout development in somatic cells Erasure and reestablishment of the imprint= The imprint is removed in germline cells
In addition to their circular chromosome, strains of E. coli that can act as donors during conjugation contain a small circular segment of DNA called a(n) ______ factor.
F
A strain of E. coli that contains an F factor and can act as a conjugation donor is designated ___, and a strain that lacks the F factor may be a recipient and is designated __.
F+ F-
If a genetic study began with your grandparents, which generation would represent you and your siblings?
F2
If you built a ball-and-stick model of the DNA double helix, where would you place the bases?
Facing each other inside the helix
Most eukaryotic species are haploid or have such a phase as a significant part of their life cycle.
False
Crossing-over can only occur during meiosis.
False Crossing over occurs much less frequently in mitosis than meiosis, but it does happen on rare occasion.
What scientist first discovered transformation?
Frederick Griffith
Which inheritance pattern is typical of the transmission of mutations in mitochondrial DNA in humans?
From the mother to all of her offspring
DNA sequences with which kind of base pairs have higher stability?
G:C base pairs
Select alternative names for genetic mapping.
Gene mapping Chromosome mapping
Which of these are examples of extranuclear genes?
Genes located on a chromosome in a chloroplast Genes located on a chromosome in a mitochondrion
What is the structure of a bacteriophage?
Genetic material surrounded by a protein coat
The branch of biology that deals with heredity and variation is
Genetics
What is the name of the scientist shown in the image who is considered the father of genetics?
Gregor Mendel
What were the main outcomes of the experiments performed by Griffith (1928)?
He found that living smooth-type bacteria killed mice. He found that living rough-type bacteria did not kill mice. He found that a mixture of living rough-type and dead smooth-type bacteria killed mice.
Why was the common garden pea, Pisum sativum, that Mendel used in his genetic experiments an ideal specimen to study genetic crosses?
He used true breeding Pisum sativum plants with two distinct genotypes and phenotypes.
DNA from the bacterial chromosome may be transferred from one cell to another if a(n) _____ cell conjugates with an F— cell.
Hfr
Which type of E. coli strain frequently transfers chromosomal genes to recipient bacterial cells?
Hfr
What event is required for genes on an Hfr chromosome to be transferred onto the recipient cell's chromosome?
Homologous recombination
The DNA from one source forms a double-stranded region with the DNA from another source during what process?
Hybridization
What is Chargaff's rule?
In double-stranded DNA, A=T and C=G
Which description matches each pattern of inheritance?
Incomplete dominance= Heterozygote has intermediate phenotype Codominance= Heterozygote expresses both alleles simultaneously Sex-limited= Trait occurs in only one of the two sexes Sex-influenced= Trait is inherited by both sexes but with different dominant/recessive patterns Incomplete penetrance= Failure to express a dominant phenotype even though the individual carries the dominant allele for that trait
What aspect of chromosome behavior is consistent with Mendel's law of independent assortment?
Independent alignment of different homologous pairs along the metaphase I plate
Select all of the true statements regarding Gregor Johann Mendel.
Mendel initially failed the licensing exam to continue teaching Mendel is regarded as a pioneer of genetics Mendel was an Augustinian priest/monk.
An organism's genotype is RrYy and it produces gametes with the genotypes RY, Ry, rY and ry with equal frequency. Which of Mendel's laws explains this fact?
Mendel's law of independent assortment
If the expression of genes in the offspring directly influences their traits, the genes are transmissible from generation to generation, the genes segregate during gamete formation, and the genes of the trait segregate independently, then the genes follow ______ inheritance patterns.
Mendelian
During which of the following phases are tetrads organized along a plate in the center of the cell?
Metaphase of meiosis I
Experiments by Creighton and McClintock coupled crosses involving two linked genes with what technology to demonstrate that crossing over can result in genetic recombination?
Microscopy of chromosome structure
Select characteristics of mitochondrial DNA mutations.
Mitochondrial DNA mutations are transmitted from a mother to all of her offspring. Mitochondrial DNA mutations may occur in somatic cells and accumulate as a person ages.
Even though offspring receive two alleles, one maternal and one paternal, during genomic imprinting only one allele is expressed. What is this phenomenon called?
Monoallelic expression
A tall pea plant is crossed with a short pea plant. WhIch of the following describe this cross?
Monohybrid cross Single-factor cross
Match each trait with the correct example. Morphological Trait Physiological Trait Behavioral Trait
Morphological Trait= The color of a flower Physiological Trait= The rate at which a bacterium metabolizes a sugar Behavioral Trait= The mating call of a bird species
Which of the following statements about eukaryotes is true?
Most eukaryotic species are diploid or have a diploid phase to their life cycle.
Select all of these that are true of mitochondrial genes.
Most mitochondrial proteins are encoded by nuclear genes. Human mtDNA carries relatively few genes. Mitochondrial DNA contains both coding and noncoding regions.
What phenomenon is observed in a population when three or more alleles can be found for a single gene?
Multiple alleles
What is realized heritability?
Narrow-sense heritability that is estimated based on the response to artificial selection
Which human mitochondrial disease is caused by a mutation in a gene required for ATP synthesis?
Neurogenic muscle weakness
Which human diseases are caused by mutations in mitochondrial DNA?
Neurogenic muscle weakness Leber hereditary optic neuropathy
What are the three phases of X chromosome inactivation?
Nucleation, spreading, and maintenance
Match the components of the general formula for the chi square test, Χ2 = Σ (O−E)2E(O-E)2E, with the correct description.
O= Observed data in each category E= Expected data in each category Σ= Sum of the calculation in each category
In a DNA double helix, where is the sugar phosphate-backbone located?
On the outside of the helix
Which of the following best describes how chromosomes are attached to microtubules during metaphase I of meiosis?
One pair of sister chromatids is linked to one pole, and the homologous pair is linked to the other
How do F+ and F- strains of E. coli differ from one another?
Only F+ strains contain an F factor.
What is contained in a minimal medium?
Only essential nutrients
Within the two-to four-cell snail embryo, which factor is responsible for the origin of dextral and sinistral shell coiling?
Orientation of the mitotic spindle
In a genetic study that begins with you and your mate, you and your mate would be considered the ______ generation.
P
Multinomial expansion equation explained
P= Probability that the unordered number of outcomes will occur n= Total number of outcomes a + b + c = n p + q + r = 1 r= Likelihood of c != Denotes a factorial (the product of all integers from n down to 1)
Binomial expansion equation explained
P= Probability that the unordered outcome will occur n= Total number of outcomes x= Number of outcomes in one category p= Individual probability of x q= Individual probability of the other category != Denotes a factorial (the product of all integers from n down to 1)
The AT/GC base-pairing rule requires that the purines (A and G) always base-pair with the pyrimidines (T and C). Why is this?
Pairing a purine with a pyrimidine ensures a consistent diameter of the helix.
What is the name for the type of bond connecting two sugar molecules via a phosphate group in the backbone of DNA and RNA?
Phosphodiester linkage
What is required in order for genetic material to be transferred between two bacterial cells by conjugation?
Physical contact between the two cells
A gene is a segment of DNA that produces a functional product, which is usually a(n) ______ or as a unit of heredity that affects an organism's _____
Polypeptide Traits
Which of the following is the correct sequence?
Prophase — prometaphase — metaphase — anaphase — telophase
During transcription, the DNA sequence of a gene is copied into a sequence of ______.
RNA
The gamete possibilities of an organism with the genotype Tt are _____ and _____.
T t
What assumptions did Crick and Watson need to make to determine the double-stranded, helical structure of DNA?
That DNA is composed of nucleotides linked together into chains That all nucleotides are linked together using the same kind of bond
Chargaff found that double-stranded DNA contains approximately a 1:1 ratio of adenine and thymine, and approximately a 1:1 ratio of cytosine and guanine. What did he conclude from this observation?
That each adenine in DNA interacts with a thymine That each cytosine in DNA interacts with a guanine
What did Chargaff conclude from the observation that in double-stranded DNA, adenine is found in the same amount as thymine, and that guanine is found in equal amounts as cytosine?
That in double-stranded DNA thymine binds to adenine while guanine binds to cytosine
What does it mean for two strands of DNA to be complementary?
The bases of one strand can base-pair with the bases of the other strand
Which of the following topics is the focus of molecular genetics?
The biochemical structure and function of DNA
What is a quantitative trait locus?
The chromosomal location of one or more genes that affect the phenotype of a quantitative trait
What is genetic transfer?
The transfer of genetic material between bacterial cells
Which of the following best describes the events of anaphase I of meiosis?
The two pairs of sister chromatids separate and move to opposite poles.
What is gene expression?
The use of a gene sequence to affect the characteristics of a cell or organism.
In a testcross, if the genes in question are linked, how does the number of recombinant offspring relate to the number of nonrecombinant offspring?
There are fewer recombinant offspring than nonrecombinant offspring.
How did Hershey and Chase discriminate between DNA and protein in their experiments to show that DNA was the genetic material of bacteriophage T2?
They labeled the DNA with radioactive phosphorous and the protein with radioactive sulfur.
When does conjugation result in the transfer of part of the bacterial chromosome to recipient cells?
When an Hfr strain conjugates with an F- strain
In somatic cells of human females one of the two X chromosomes is randomly turned off. What is this mechanism called?
X-chromosome inactivation
What is the primary role of the X-inactivation center (Xic)?
X-chromosome inactivation
The short region on the X chromosome that plays an important role in X chromosome inactivation is the _____?
X-inactivation center (Xic)
_____ genes are those that are physically located on the X chromosome.
X-linked
Which of the following formulas is the correct equation for calculation of the mean? In these equations, XX is the mean, ΣX is the sum of all values in the group, and N is the number of individuals in the group.
X= (sum) x/N
A person who has somatic cells with two Barr bodies could have which of the following genotypes?
XXX XXXY
A deletion is best defined as the loss of ______.
a chromosome segment
A cell with at least one copy of a wild-type allele will typically produce ______.
a functional version of the protein specified by this allele
To study cancer in an animal model, geneticists produced a mouse that was missing both alleles of a tumor suppressor gene called p53. This change at the genetic level is called ______.
a gene knockout
A testcross is a cross between ______.
a heterozygote and a recessive homozygote
A cross between a true breeding tall plant and a true breeding short plant is an example of ______.
a hybridization experiment
A cytogeneticist ______.
a scientist who studies chromosomes under the microscope
Mitotic nondisjunction in a diploid cell produces ______.
a trisomic and a monosomic daughter cell
A piece of a chromosome that has lost its centromere is called a(n) ____ fragment.
acentric
A virus that infects bacteria is called a(n)
bacteriophage
Unlike trisomy for autosomes, trisomy X is often without serious phenotypic consequences. This is due to the fact that the additional X chromosome is converted to an inactive _____ in the somatic cells of the adult.
barr bodies
Most bacterial cells divide by ______.
binary fission
The strength of the association between two variables can be reported as a value that ranges between -1 and +1. This value is called the ___ coefficient.
correlation
Eukaryotic cells that are destined to divide progress through G1, S, G2, and M phases, which are collectively known as the ___
cell cycle
In a DNA double helix, the bases point towards the ______ of the helix.
center
Each centrosome of an animal cell contains a pair of ________ at right angles to each other.
centrioles
The two microtubule-organizing centers (MTOCs) that form the mitotic spindle of animal cells are called ______.
centrosomes
A _______ test is used to distinguish between linkage and independent assortment.
chi square
What is the name for the test that utilizes the following formula? Χ2 = Σ (O−E)2E
chi square test
The structure that is formed during crossing over is called a(n) , because it looks like the Greek letter chi, χ.
chiasma
The endosymbiosis theory explains how eukaryotic cells developed the cellular organelles: _____ and _____
chloroplasts, mitochondria
After replication, each chromosome consists of two copies called ___
chromatids
All of the following are fundamental principles of the chromosome theory of inheritance except ______. Options: chromosome replication occurs during the S phase of the cell cycle during the formation of haploid cells, different types of chromosomes segregate independently of each other each parent contributes one set of chromosomes to its offspring chromosomes contain the genetic material that is transmitted from parent to offspring and from cell to cell chromosomes passed along, generation after generation, from parent to offspring
chromosome replication occurs during the S phase of the cell cycle (true but not a part of this theory)
The structures within all living cells that contain the genetic material are called ______
chromosomes
The genome located in the nucleoid of a mitochondrion or chloroplast consists of a ______ chromosome.
circular, double-stranded DNA
A crossover is unlikely to occur in the region between two genes when they are ______.
close together
A technique called __________ (CGH) can be used to determine whether a cancer cell has changes in chromosome structure, such as duplications or deletions.
comparative genomic hybridization
You are trying to solve a genetics problem that asks you to determine how two proteins differ from one another. Which problem-solving strategy would be most helpful for this question?
compare and contrast
A Streptococcus pneumoniae cell may begin to express competence proteins if a nearby cell secretes the _____ ______ peptide.
competence stimulating
A bacterial cell that is able to take up foreign DNA from its environment is called a(n) ______ cell.
competent
When the bases in one strand of DNA can hydrogen bond exactly with the bases in another strand of DNA, then the two strands of DNA are said to be ______.
complementary
The following pathway is proposed to explain the inheritance of purple flower color in pea plants: Colorless Precursor→Colorless Intermediate→Purple Pigment. A dominant allele for Gene C provides an enzyme that converts Colorless Precursor→Colorless Intermediate. A dominant allele for Gene P provides an enzyme that converts Colorless Intermediate→Purple Pigment. An explanation of why plants with CCpp and ccPP genotypes have white petals while plants with the CcPp genotype have purple flowers is
complementation occurs in the CcPp plant, showing that the mutations preventing color in the white plants are in different genes.
Characteristics that are determined by several genes and are also influenced by environmental factors are called ___ traits.
complex
A temperature-sensitive allele that causes the death of an organism only with exposure to a specific range of temperatures is a(n) ______ allele,
conditional lethal
An allele that leads to the death of the organism only under specific environmental influences is called a(n) ______ allele,
conditional lethal
Quantitative traits are ______.
controlled by multiple genes
DNA segments of 1000 bp or more in length which exist in differing numbers of copies among individuals within the same species are described by the term _________ (CNV).
copy number variation
During meiosis I in an individual carrying a reciprocal translocation, the homologous chromosomes synapse with each other via the formation of a structure that contains four pairs of sister chromatids. This unusual structure is called a translocation ______.
cross
The interchange of corresponding chromatid segments of homologous chromosomes during prophase I of meiosis is called ______ ______.
crossing over
What is the name of the process in diploid eukaryotic species where homologous chromosomes exchange pieces with each other?
crossing over
Genetic mapping is based on estimating the distance between linked genes based on the likelihood that a ___ will occur between them.
crossover
During conjugation, the chromosome in the Hfr strain is first _____, then transferred into the F— cell, where it may ______ with the homologous region of the recipient cell's chromosome.
cut recombine
A scientist who examines the chromosomal composition of a particular cell is called a(n) ___
cytogeneticists
A change in chromosome structure where a portion of the chromosome is missing is called a(n) _____
deletion or deficiency
DNA is an abbreviation for
deoxyribonucleic acid
DNA and RNA nucleotides have three main parts, one of which is a sugar. In DNA the sugar is ___
deoxyribose
What kind of sugar is found in DNA nucleotides?
deoxyribose
When comparing the structural features of RNA with the structural features of DNA, DNA uses the sugar and ____ RNA uses the sugar ____.
deoxyribose ribose
A chromosome that possesses two centromeres is called a(n) _____ chromosome.
dicentric
A cell or organism that contains two copies of every chromosome is said to be
diploid or somatic
Morgan proposed that the likelihood of crossing over depends on the _____ between two genes.
distance
Alleles of two different genes will be randomly distributed into gametes during the formation of haploid cells. This statement summarizes which of Mendel's laws?
law of independent assortment
Which law states that two copies of a gene separate from each other during transmission from parent to offspring?
law of segregation
Which of Mendel's laws accounts for the genotype of the gametes as shown in the figure?
law of segregation
Which of Mendel's laws explains why a gamete only has one copy of each gene?
law of segregation
The length of the Hfr chromosome that is transferred to a recipient cell during conjugation is directly related to the ______.
length of time allowed for conjugation to occur
The size of a human mitochondrial chromosome is ______ the size of a typical bacterial chromosome.
less than 1%
An allele that can lead to the death of an individual is a(n) ______ allele.
lethal
Genes that are physically located on the X chromosome are called X- ______ genes.
linked
When conducting a chi square analysis to determine if genes in a two factor cross are linked or independently assorted, scientists begin with the hypothesis that the genes are not _____
linked
The site where a gene is found on a particular chromosome is called its ______
locus
The chromosomal location of one or more genes that influence a quantitative trait is called a quantitative trait ___
locus or loci
In conducting a chi square analysis of a two factor cross, if the chi square value is ______, we cannot reject the null hypothesis, and we infer that the genes assort _____.
low independently
A large molecule that is composed of repeating units of smaller building blocks is called a(n)
macromolecule (aka polymer)
In bees, ______.
males are haploid, while females are diploid
The X-Y system of sex determination is used by ______.
mammals
One ______ equals 1% recombinant offspring in a testcross.
map units
Distance on a chromosome is generally measured in ______.
map units centiMorgans
In an inheritance pattern called _________, the genotype of the mother directly determines the phenotype of her offspring for a given gene.
maternal effect
Chloroplasts and mitochondria are inherited through the cytoplasm of the egg. This type of extranuclear inheritance is called ______.
maternal inheritance
The type of inheritance that occurs because extranuclear genes are inherited through the cytoplasm of an egg is called ____
maternal inheritance
A mitochondrion or chloroplast ______ one nucleoid.
may have more than one
The sum of all of the values of a parameter within a group divided by the number of individuals in the group is defined as the ______.
mean
Eukaryotic cells that are diploid can divide by ______ to produce haploid sex cells.
meiosis
In eukaryotes, ______ is the type of cell division that is responsible for the production of gametes.
meiosis
In ______ of meiosis, the bivalents (which are also termed tetrads) are aligned along the center of the cell.
metaphase I
At the molecular level, one way genomic imprinting is regulated is by DNA ______
methylation
A growth medium that contains only the essential nutrients required for the growth of a wild-type bacterial species is called a(n) _____ medium.
minimal
In a bacterial conjugation experiment, the unit used for genetic mapping is the ______.
minute
The image is depicting organisms that researchers often use in the laboratory. These are called _____organisms. (image shows mice, flys, etc.)
model
The goal of selective breeding is to ______.
modify phenotypes in economically important plants and animals
Which area is devoted to the study of the structure of DNA and how it functions?
molecular genetics
Which area of genetics focuses on the biochemical understanding of DNA and gene expression?
molecular genetics
A macromolecule is best described as a ______.
molecule composed of repeating units of smaller building blocks
The color of a butterfly, such as the ones shown here, is an example of a(n) ______ trait.
morphological
What is the shape of the majority of plasmids?
most circular, some similar
A single gene for white coloring on the coats of dogs has four alleles with a hierarchy of dominance. Various combinations of these alleles can lead to solid coat, Irish-spotting, piebald-spotting and white coats. This inheritance pattern for white coloring is due to the existence of ______ for the gene for coat coloring.
multiple alleles
In a DNA molecule, information is contained in the sequence of ______.
nitrogenous bases
In meiosis, crossing over refers to the physical exchange of pieces between ______ chromatids of ______ chromosomes.
non-sister; homologous
Improper separation of chromosomes can occur after fertilization in one of the body's somatic cells. This mechanism is referred to as mitotic ___
nondisjunction
The failure of chromosomes to segregate properly during mitosis or meiosis is called ____
nondisjunction
The term meiotic _____ refers to the failure of chromosomes to separate normally during meiosis. This results in haploid cells that have too many or too few chromosomes.
nondisjunction
A gene that produces a beneficial product that is not absolutely required for survival of the organism is called a(n) ______ gene.
nonessential
A Robertsonian translocation occurs when two ______ chromosomes lose their short arms and fuse to form a large single chromosome.
nonhomologous acocentric
Both DNA and RNA are ______ acids. Multiple choice question.
nucleic
The four different categories of large organic molecules found within cells are
nucleic acids proteins carbohydrates lipids
In chloroplasts, DNA is found in regions called ______ , as indicated by the lines in the image.
nucleoids
A DNA molecule is a linear sequence of subunits called
nucleotides
What are the subunits of DNA?
nucleotides
Genes located on chromosomes are called nuclear genes because they are located in the cell ___
nucleus
If it is assumed that there is no real difference between the observed data and the expected data it is called a
null hypothesis
In chi square statistical analysis, the _______ assumes there is no difference between observed and expected values.
null hypothesis
A frequency distribution is a graph that shows the ______.
number of individuals in various phenotypic categories
A cell that is haploid contains ______ set(s) of chromosomes.
one
The constant diameter of the double helix is ensured because hydrogen bonding is always between a ___ base (A and G) and a ___ base (T and C).
purines pyrimidines
The length of an ear of corn is an example of a(n) _____ trait.
quantitative
When narrow-sense heritability is estimated based on the response to artificial selection, it is referred to as ___ heritability.
realized
A lethal allele usually shows a(n) ______ inheritance pattern.
recessive
A trait that is masked by another trait but reappears in subsequent generations is ______.
recessive
For Labrador Retrievers the dominant allele B for gene 1 leads to black coat while the recessive allele b leads to brown coat. Alleles of gene 2 can change this color, with the dominant allele E having no effect but genotype ee changing either black or brown to yellow color. For dogs with the genotype BBee, the effect of gene 2 on gene 1 is ______.
recessive epistasis
For X-linked genes, ______ crosses give different outcomes.
reciprocal
Offspring that display combinations of traits that are different from those of either parent are called ____.
recombinant
Offspring that display combinations of traits that are different from those of either parent are called ______.
recombinant
The number of ____ offspring divided by the total number of offspring multiplied by 100 equals the genetic ____ distance.
recombinant map
After conjugation, a recipient cell may have a new combination of alleles if homologous _______ occurred between the transferred Hfr chromosome and the original chromosome of the bacterial cell.
recombination
In a testcross, the amount of ______ can be used as an estimate of the physical ____ between two genes on the same chromosome.
recombination distance
Results from the experiments by McClintock and Creighton supported the view that genetic _____ involves a physical exchange between ____ chromosomes.
recombination homologous
Telomeres are ______.
repeated sequences of DNA that are found at the end of chromosomes
Identical or similar DNA sequences that occur multiple times on a chromosome are called _____ sequences.
repetitive
Transposable elements are examples of ______.
repetitive sequences
The two types of nucleic acids are known as ______ and ______.
ribonucleic acid (RNA) deoxyribonucleic acid (DNA)
The nucleotides used to make RNA and DNA are made from three main parts. One of those parts is a sugar molecule; in RNA the sugar molecule is called ___
ribose
What is the sugar found in nucleotides used to make RNA?
ribose
Consider a homologous pair of chromosomes of a particular individual, where one homolog carries a single copy of gene A while the other carries two copies of the same gene. The latter chromosome is said to have undergone a(n) ______
segmental duplication
Mendel's law of _______ can be explained by the homologous pairing and separation of chromosomes during meiosis.
segregation
A certain allele of the insulin-like growth factor 1 gene is very common in small dogs but is almost absent from large breeds of dogs. The differences in the prevalence of this allele in different types of dogs can be attributed to ______.
selective breeding
Kale, broccoli, Brussels sprouts, cabbage, and kohlrabi have all been derived from the wild mustard plant by ___
selective breeding
An allele that causes death in some, but not all individuals in a population is a(n) ____ allele.
semilethal
Suppose that there are two male mice who are homozygous for the same allele. They are raised under the same environmental conditions: receiving the same types of foods in cages exposed to the same ranges of temperature. Despite this attention to animal care, one mouse dies and the other survives. Which type of allele is likely to be responsible for this death?
semilethal allele
Nondisjunction occurs when chromosomes do not ______.
separate properly during meiosis
A complex trait is a trait that is influenced by ______.
several genes and the environment
In humans, a gene found on the Y chromosome but not on the X chromosome is a ______- linked gene.
sex
Chromosomes that determine whether an individual is a male or female are called ____
sex chromosomes
Chromosomes that differ between males and females are called ____?
sex chromosomes
Chromosomes that differ in size and composition between males and females are called ______.
sex chromosomes
Which inheritance pattern is shown for a trait occurring in one sex but not in the opposite sex?
sex limited inheritance
For ______ inheritance, a given allele is dominant in one sex and recessive in the opposite sex
sex- influenced
A trait that is expressed in only one sex and not seen in the opposite sex shows ______ inheritance.
sex-limited
In humans, a gene found in the X chromosome but not the Y chromosome is called a(n) ______ gene.
sex-linked
Fungi can reproduce ______.
sexually or asexually
The two copies of a replicated chromosome are called ______.
sister chromatids
Which chromosome 15 genes are lost in the deletion causing Prader-Willi syndrome?
snoRNA genes SNRPN NDN
In a multicellular organism, cells that are not directly involved in sexual reproduction are called _____ cells
somatic
Patterns of imprinting are maintained in what type of cells throughout development?
somatic
Male animals produce mature sperm by a process called _____
spermatogenesis
When a diploid fungus zygote undergoes meiosis, it produces four haploid cells, which are called _____.
spores
The competence-stimulating peptide of Streptococcus pneumoniae ______.
stimulates nearby cells to express competence proteins
The correlation coefficient is a measure of the ______.
strength of the relationship between two variables
When genetic and environmental factors are independent of one another, and genetic variance (VG) and environmental variance (VE) are the only factors that determine phenotypic variance (VP), then VP is equal to the ______.
sum of VG and VE.
During prophase of meiosis I, homologous chromosomes recognize and begin to align with each other via a process called _______
synapsis
Because bacterial cells contain one large circular chromosome, all genes within that chromosome are ______.
syntenic
The ends of a eukaryotic chromosome are called ____
telomeres
During ______ of meiosis, the pairs of sister chromatids (or dyads) reach the opposite poles of the cell, where in most cases, they decondense.
telophase I
Himalayan coloring in rabbits is due to a dominant allele that codes for a tyrosinase enzyme which participates in the production of the dark pigment melanin. In cold temperatures, dark coloring is only found in the ears, nose and feet of the animal. White coloration develops on body areas where blood flow keeps the animal warm. The tyrosinase enzyme is most likely due to a ____?
temperature-sensitive allele
In fruit flies, the para mutation causes a change in a sodium channel necessary for conducting nerve signals. Mutant flies have normal movement at 22oC but become immediately paralyzed at 29oC. The paralysis is reversed when the temperature returns to 22oC. The para mutation is most likely due to a ______.
temperature-sensitive allele
Consider a normal chromosome that has broken into two separate pieces, one of which is lost because it lacks a centromere. The resultant chromosome is said to have undergone a(n) ______ deletion.
terminal
In a Drosophila melanogaster ________ a fly with a dominant phenotype and unknown genotype is mated to one that has a recessive phenotype.
testcross
The goal of a _____ is to determine the frequency with which a doubly ____ parent produces recombinant gamete types.
testcross heterozygous
Spermatogenesis takes place in the ______.
testes
A bivalent is also called a ______ because it is composed of four chromatids.
tetrad
A group of four fungal spores is called a _____
tetrad
An organism's genome consists of
the DNA found in all of its chromosomes
As shown in the image, X chromosomes are randomly inactivated during embryonic development. This is also called ______.
the Lyon hypothesis
When a daughter can inherit a sex-linked allele from either her mother or father, it must be located on ______.
the X chromosome
The following pathway is proposed to explain the inheritance of purple flower color in pea plants: Colorless Precursor→Colorless Intermediate→Purple Pigment. A dominant allele for Gene C provides an enzyme that converts Colorless Precursor→Colorless Intermediate. A dominant allele for Gene P provides an enzyme that converts Colorless Intermediate→Purple Pigment. An explanation for why plants with the ccPp genotype have white petals while plants with the CcPp genotype have purple petals is ______.
the cc genotype exerts epistasis over the Pp genotype, preventing purple color formation
Chiasmata refers to ______.
the connections that result from crossing-over
A genotype-environmental interaction exists when _______.
the environmental effects on phenotype differ according to genotype
Pink four o'clock flowers have one copy of the allele for red petals and one copy of the allele for white petals. The best explanation for the pink petal color is __________?
the single allele for red petals causes the production of about 50% of the normal enzyme so petal color is lighter
Molecular genetics studies ______.
the structure of DNA
Chromosomes are best defined as ______.
the structures within living cells that contain the genetic material
A pea plant will be tall if it has a least one tall allele in its genome. A plant will be dwarf only if it has two alleles for the dwarf phenotype. What conclusion can be drawn based on this information?
the tall allele is dominant to the dwarf allele
The great majority of inversions do not cause phenotypic consequences because ______.
the total amount of genetic material does not change in a given chromosome
The transmission pattern of two or more characters is affected by?
their linkage on a chromosome.
If a correlation coefficient is found to be statistically significant, it means that ______.
there is a true association between the two variables
f a correlation coefficient is found to be statistically significant, it means that ______.
there is a true association between the two variables
Individuals with an HbS HbS genotype suffer from sickle cell anemia because ______.
they produce hemoglobin S, a variant that causes their red blood cells to form a crescent shape when oxygen concentration is low
Polyploidy is best defined as the presence of ______.
three or more sets of chromosomes
Suppose that a person has blonde hair. In genetic terms, blonde is the ____ and hair color is the ____
trait or variant character or characteristic
When a structural gene is expressed, its DNA sequence is ____ into RNA, which is then _____ to produce a polypeptide.
transcribed, translated
The process by which a DNA sequence is copied into an RNA sequence is called
transcription
An Hfr bacterial strain is very efficient at ______.
transferring genes from its chromosome to F— strains
Frederick Griffith is known for the discovery of ______.
transformation
The experiments of Avery, MacLeod, McCarty were trying to determine the _____ in the experiments by Frederick Griffith.
transforming substance
The inheritance of genes and the way that genes influence traits is the focus of _____ genetics.
transmission
Which field of genetics focuses on how genes are passed on from parents to offspring?
transmission genetics
An organism that has three sets of chromosomes is called a(n) ______ , while one with four sets is called a(n) ____.
triploid tetraploid
A heterogametic sex produces two types of sex cells, while a homogametic sex produces sex cells of only one type.
true
An organism's environment can affect its morphological and physiological traits.
true
Consider a situation where only one of two mutually exclusive events can occur. True or false: If the probability of one event occurring is 75%, the probability of an opposite event occurring would then be 25%.
true
Crick and Watson assumed that the nucleotides in DNA were all linked together in linear chains, and using the same kind of bond.
true
Each species has a particular chromosome composition.
true
The term diploid means that a cell or organism has ______.
two copies of every chromosome
Covariance is a measure of the relationship between ______.
two different variables
In bread wheat, the color of the hull can be dark red, white, or various intermediate shades of red. Genetic analysis of this trait has demonstrated that it is controlled by ______.
two loci with additive effects on hull color
A bivalent, or tetrad, consists of ______.
two pairs of sister chromatids
Colorblindness is due to an X-linked recessive allele. To be colorblind, females must inherit ______ copy(ies) of this allele and males must inherit ______ copy(ies).
two, one
Genotype-environmental interaction (represented by VG x E ) is ______.
variance attributed to interactions between genetic and environmental factors
A term used to describe the specific properties of a character, such as describing the eye color in a person as brown, is a ______.
variant
Genetic differences within individuals of the same species or between different species is referred to as genetic ______
variation
Differences in inherited traits among individuals within a population are referred to as genetic
variation or diversity
A trait that a son can inherit only from his mother must be due to an allele found on ______.
x chromosome
In humans, an individual with Klinefelter syndrome has a sex chromosome composition of ______.
xxy
If there is no relationship between two variables, the correlation coefficient will be ______.
zero