question

It is the job of geneticists to study ________.

answer

~ how traits and diseases are passed from generation to generation ~ why alleles of some genes occur more frequently in one population than in others ~ the molecules that make up genes and how genes are turned on and off

question

The chemical subunits which form genetic code in DNA are called ________.

answer

nucleotides

question

A gene product becomes a functional protein when ________.

answer

its polypeptide is folded into a three-dimensional shape

question

The different visible characteristics that distinguish one individual from another are called ________.

answer

traits

question

Which approach to the study of genetics reconstructs the pattern followed by a trait as it passes through several generations of a family? a. population genetics b. pedigree analysis c. cytogenetics d. transmission genetics

answer

b. pedigree analysis

question

Which technique may be used to detect abnormalities in chromosome size, shape, or number? a. gene therapy b. recombinant DNA technology c. molecular genetics d. karyotype

answer

d. karyotype

question

The ________ is a controversial issue in applied genetics. a. use of recombinant-DNA derived growth hormone in milk production b. all of the choices c. environmental impact of genetically modified organisms d. sale and consumption of food modified by recombinant DNA technology

answer

b. all of the choices

question

In the early 1900s, eugenics laws were passed in the United States which provided for ________.

answer

sterilization of people who were defined as genetically, intellectually, and morally inferior

question

In the late 1930s, the eugenics movement in the United States declined partly due to ________.

answer

the close association between eugenics and the government of Nazi Germany

question

A protein produced by bacteria which cuts viral DNA into pieces is called ________.

answer

a restriction enzyme

question

A collection of clones that contains all the genes carried by an organism is called ________.

answer

a genomic library

question

Which of the following statements about genetically modified products is NOT true? a. Genetically modified sheep, rabbits, and cows can produce medically important human proteins in their milk. b. Human insulin used to treat diabetes can be produced in modified bacteria. c. More than 60% of the corn and 80% of the soybeans grown in the United States are genetically modified. d. The use of herbicide-resistant corn and soybeans can decrease the use of chemical herbicides.

answer

d. The use of herbicide-resistant corn and soybeans can decrease the use of chemical herbicides.

question

DNA microarrays (gene chips) are used to ________. a. diagnose some infectious diseases b. diagnose some cancers c. determine which genetic disorder someone has, is predisposed to, or will develop d. all of the choices

answer

d. all of the choices

question

Cells exchange large molecules with the environment through their ________ by means of energy-requiring systems.

answer

plasma membrane

question

Ribosomes ________. a. attach to the outer surface of the rough endoplasmic reticulum (RER) b. are the most numerous cellular structures c. are the sites of protein synthesis d. all of the choices

answer

d. all of the choices

question

Which membranous organelles are the sites of energy production in cells? a. smooth endoplasmic reticulum b. mitochondria c. golgi complex d. lysosomes

answer

b. mitochondria

question

Which of the following structures is NOT a part of the nucleus? a. chromatin b. nucleolus c. chromosomes d. vesicles

answer

d. vesicles

question

During which stage of the cell cycle are chromosomes duplicated?

answer

interphase

question

In which phase of mitosis are duplicated chromosomes lined up at the equator of the cell?

answer

metaphase

question

Which of the following statements does NOT apply to centromeres? a. While attached to the centromere, replicated chromosomes are called sister chromatids. b. Centromeres divide and migrate to opposite poles of the dividing cells. c. The location of a centromere gives a chromosome its characteristic shape. d. Centromeres are a region of a chromosome to which microtubule fibers attach during cell division.

answer

b. Centromeres divide and migrate to opposite poles of the dividing cells.

question

During which stage of the cell cycle are chromosomes condensed?

answer

mitosis

question

The function of meiotic cell division is to ________. a. all of the choices b. produce haploid cells c. produce male and female gametes d. maintain constant chromosome number from generation to generation

answer

a. all of the choices

question

In which stage of meiosis do paired homologous chromosomes separate?

answer

anaphase I

question

Mitosis produces ________ daughter cells, and meiosis produces ________ daughter cells.

answer

2 diploid; 4 haploid

question

Which two events in meiosis produce new combinations of genes in gametes?

answer

random assortment & crossing over

question

In crossing over, genetic material is exchanged between ________. a. maternal and paternal homologous chromosomes b. maternal and paternal gametes c. male and female sex chromosomes d. sister chromatids

answer

a. maternal and paternal homologous chromosomes

question

In spermatogenesis, ________ are produced by mitosis and ________ are produced by meiosis.

answer

primary spermatocytes; spermatids

question

In oogenesis, which cell becomes the ovum?

answer

secondary oocyte

question

What is the function of a polar body?

answer

To give up its cytoplasm to the oocyte that will become an egg.

question

What is the difference between spermatogenesis and oogenesis? a. All of the choices. b. In spermatogenesis, sperm contain the minimum amount of cytoplasm; in oogenesis an ovum contains the maximum amount of cytoplasm. c. Spermatogenesis occurs from puberty until death; in oogenesis all mitotic divisions take place during embryonic development. d. Spermatogenesis produces 4 sperm; oogenesis produces 1 oocyte.

answer

a. All of the choices.

question

In human oogenesis or spermatogenesis, how many different genetic combinations can be produced by random assortment alone?

answer

2^23

question

In oogenesis, when does the secondary oocyte complete meiosis II to become an ovum?

answer

at fertilization

question

Why would Mendel study pea plants if he wanted to learn about human inheritance? a. Compared to humans, inheritance in pea plants is more clearly defined. b. All of the choices. c. The generation time in humans is too long. d. For ethical reasons, humans can't be used in experimental genetics.

answer

b. All of the choices.

question

Which of the following is NOT one of the three properties Mendel was looking for when choosing an experimental subject? a. Offspring of self-fertilized plants should be fully fertile. b. The subject should have a number of different traits that can be studied. c. The subject should be self-fertilizing and have a flower structure that minimizes accidental pollination. d. The subject should be a common food plant.

answer

d. The subject should be a common food plant.

question

In Mendel's study of single traits, crossing parental (P1) plants that had smooth seeds with those that had wrinkled seeds, what was the most important characteristic of the P1 generation? a. The P1 generation were true-breeding. b. The female parent had smooth seeds and the male parent had wrinkled seeds. c. The male parent had smooth seeds and the female parent had wrinkled seeds. d. The P1 generation were heterozygous.

answer

a. The P1 generation were true-breeding.

question

Based on his results with single crosses, Mendel concluded that ________. a. it was important to distinguish between the appearance of an organism and its genetic constitution b. each generation must carry two factors (genes) for each characteristic c. factors (genes) that determine traits can be hidden or expressed d. all of the choices

answer

d. all of the choices

question

If you cross parents SS x ss, how many different combinations of alleles do you expect to find in the F1 generation?

answer

1

question

Mendel's principle of segregation demonstrates that ________. a. most male plants have wrinkled seeds and most female plants have smooth seeds b. in gamete formation, members of a gene pair separate so that only one member is included in each gamete c. the F1 generation has no recessive genes d. the P1 generation is heterozygous

answer

b. in gamete formation, members of a gene pair separate so that only one member is included in each gamete

question

When Mendel experimented with crosses using two traits, color and shape, how did he interpret the 9:3:3:1 ratio of the four phenotype combinations which appeared in the F2 generation?

answer

The two traits were inherited separately, each in a 3:1 ratio.

question

How many different genotypes are produced in the F2 generation of a dihybrid cross?

answer

9

question

A chi square test is used to ________.

answer

determine if the results in an experiment fall within a statistical range of probability of the expected results

question

Mendel's principle of independent assortment of genes in gametes is the physical result of ________. a. the random alignment of homologous chromosomes in meiosis I b. the random alignment of homologous chromosomes in mitosis c. crossing over during chromosome condensation in mitosis d. crossing over during chromosome condensation in meiosis

answer

a. the random alignment of homologous chromosomes in meiosis I

question

It is estimated that about ________ genes are carried on human chromosomes.

answer

20,000 to 25,000

question

Applying rules of Mendelian inheritance to humans, if two parents with brown eyes have three children with blue eyes and one child with brown eyes, then ________.

answer

blue eyes must be recessive

question

If two parents are both carriers (heterozygous) for two different recessive genetic traits, what is the probability that any one of their children will express BOTH traits in a dihybrid cross?

answer

1 in 16

question

Which of the following is used to study the inheritance of specific traits in humans? a. all of the choices b. the dihybrid cross c. the monohybrid cross d. pedigree construction

answer

d. pedigree construction

question

A pedigree is used ________. a. to establish how a trait is inherited b. to identify those at risk of developing or transmitting a trait c. as a resource for establishing biological relationships within a family d. all of the choices

answer

d. all of the choices

question

Which of the following statements is true of MN blood groups? a. All of the choices. b. M and N represent two different alleles of the same gene. c. M and N are codominant. d. M and N represent surface glycoproteins.

answer

a. All of the choices.

question

Which of the following statements is true of ABO blood types? a. A, B, and O represent multiple alleles of the same gene. b. O represents a lack of surface antigen. c. A and B represent surface antigens. d. All of the choices.

answer

d. All of the choices.

question

The form of gene interaction in which one gene prevents or masks the expression of another gene is called ________.

answer

epistasis

question

It is relatively difficult to interpret how traits are inherited in humans because ________. a. inheritance in humans works differently than inheritance in garden peas b. humans produce relatively few offspring c. generation time is faster in humans than in garden peas d. it is easier to mate humans than it is to fertilize garden peas

answer

b. humans produce relatively few offspring

question

Pedigree analysis can be used to determine if a trait shows ________ inheritance. a. mitochondrial b. all of the choices c. X-linked or Y-linked d. autosomal dominant or autosomal recessive

answer

b. all of the choices

question

The Online Mendelian Inheritance in Man (OMIM) database ________. a. assigns a catalog number to each trait b. contains text, pictures, references, and links to other databases c. is accessible through the World Wide Web d. all of the choices

answer

d. all of the choices

question

A trait that can be inherited equally by males or females, and from unaffected parents, is probably a/an ________ trait.

answer

autosomal recessive

question

Cystic fibrosis is a disabling and fatal disorder inherited as a/an ________ trait.

answer

autosomal recessive

question

The CF gene ________. a. affects glands that produce mucus, digestive enzymes, and sweat b. was mapped to a region of chromosome 7 using recombinant DNA techniques c. all of the choices d. encodes a protein which is inserted into the plasma membrane of specific gland cells

answer

c. all of the choices

question

Which of the following statements is NOT true of sickle cell anemia? a. It is an autosomal dominant disorder. b. It causes the production of abnormal hemoglobin protein. c. The abnormal gene confers resistance to malaria. d. It is most common in families with West African origins.

answer

a. It is an autosomal dominant disorder.

question

A trait in which every affected individual has at least one affected parent, and that affects males or females equally, is probably ________.

answer

autosomal dominant

question

Individuals with the autosomal dominant disorder Marfan syndrome ________. a. are unable to participate in active sports b. have weak connective tissue around the aorta, causing it to split open c. all of the choices d. tend to be short and heavy

answer

b. have weak connective tissue around the aorta, causing it to split open

question

A hemizygous trait ________. a. describes unpaired genes on the X chromosome in males b. can be either homozygous or heterozygous c. is expressed in the dominant but not in the recessive condition d. can only be inherited by a female on the X chromosome

answer

a. describes unpaired genes on the X chromosome in males

question

A trait that is passed from a father to all of his daughters and none of his sons is most likely ________.

answer

X-linked dominant

question

An X-linked recessive trait would be expressed in ________ but NOT in ________.

answer

the son of an affected mother, the son of an affected father

question

If a mother and father with normal vision have a son who is color blind, which of the following must be true? a. The father is a carrier for color blindness. b. Color blindness is an X-linked dominant trait. c. The mother is a carrier for color blindness. d. Both parents are carriers for color blindness.

answer

c. The mother is a carrier for color blindness.

question

Duchenne muscular dystrophy, which causes progressive weakness and loss of muscle tissue, is a/an ________ trait.

answer

X-linked recessive

question

The protein dystrophin, which is absent in Duchenne muscular dystrophy, normally ________ in muscle cells. a. supports the connective tissue in the aorta b. produces the enzyme alpha-galactosidase A c. metabolizes porphyrins d. connects actin with the cytoplasmic side of the plasma membrane

answer

d. connects actin with the cytoplasmic side of the plasma

question

A trait on the Y chromosome will be expressed ________. a. in alternating generations b. only in sons who are homozygous for the trait c. in all children of the same father d. in all males in a direct line of descent from father to son

answer

d. in all males in a direct line of descent from father to son

question

Mitochondrial genes are inherited ________. a. from the mother through the cytoplasm of the egg b. only by females in a direct line of descent from mother to daughter c. equally from the mother and father d. only in males in a direct line of descent from father to son

answer

a. from the mother through the cytoplasm of the egg

question

Mutations in mitochondrial genes generally affect ________. a. the ability to produce dystrophin b. early stages of sexual differentiation c. the production of CFTR protein d. the amount of energy available for cellular functions

answer

d. the amount of energy available for cellular functions

question

Variations in phenotypic expression may be caused by ________. a. age b. the environment c. all of the choices d. interactions with other genes in the genotype

answer

c. all of the choices

question

________ is the probability that a disease phenotype will be present when a disease genotype is present.

answer

Penetrance

question

________ defines the degree of expression for a particular trait.

answer

Expressivity

question

Which of the following is an example of continuous variation? a. height in humans b. all of the choices c. color blindness in humans d. height in pea plants

answer

a. height in humans

question

A ________ trait is defined as the interaction of one or more environmental factors and two or more genes.

answer

multifactorial

question

Understanding complex traits is difficult because ________. a. in some cases, genes alone and environment alone produce no observable trait b. all of the choices c. environmental components can be hard to identify and measure d. each gene contributes only a small amount to the phenotype

answer

b. all of the choices

question

A trait in which the distribution of phenotypes follows a bell shaped curve ________. a. is typical of polygenic inheritance b. can't be explained by Mendelian inheritance c. is difficult to measure in populations d. is usually quantified by counting rather than measurement

answer

a. is typical of polygenic inheritance

question

Which of the following traits is NOT polygenic? a. height in pea plants b. human intelligence c. height in tobacco plants d. human skin color

answer

a. height in pea plants

question

As the number of loci that controls a trait increases, ________. a. all of the choices b. the chance for environmental factors to override genotypic differences between classes decreases c. the number of phenotypic classes increases, approaching a bell-shaped curve d. there is greater phenotypic difference between the individual classes

answer

c. the number of phenotypic classes increases, approaching a bell-shaped curve

question

In a polygenic system, the tendency of parents who have extreme phenotypes to have offspring with average phenotypes is called ________.

answer

regression to the mean

question

Which of the following is NOT an important characteristic of multifactorial traits? a. Offspring are divided into two classes that do not overlap. b. Genes controlling the trait act additively. c. Environmental factors interact with the genotype to produce the phenotype. d. Traits are polygenic.

answer

a. Offspring are divided into two classes that do not overlap.

question

The threshold model ________. a. is an expression of how much of the observed variation in a phenotype is due to differences in genotype b. estimates the risk that a multifactorial disease will recur in a family c. is an indirect method of studying the genetic components of multifactorial traits d. describes the environmental components affecting multifactorial traits

answer

c. is an indirect method of studying the genetic components of multifactorial traits

question

Heritability measures how much ________ is due to differences in genotype. a. phenotypic variation in a population b. different environments in which genotypes are expressed c. discontinuous distribution of some multifactorial traits d. recurrent risk

answer

a. phenotypic variation in a population

question

For a polygenic trait such as TRC (fingerprints) with little or no environmental influence, what correlation coefficient would you expect between a parent and child?

answer

0.50

question

A correlation coefficient measures ________. a. the fraction of genes shared by two relatives b. the number of phenotypic classes for a particular genetic trait c. the phenotypic variance of a trait in a population that is attributed to genotypic differences d. the phenotypic variance of a trait in a population that is attributed to differences in the environments

answer

a. the fraction of genes shared by two relatives

question

In a study of fingerprints (Total Ridge Count), one group of twins had an observed correlation coefficient of 0.95 while a second group of twins had a correlation coefficient of 0.49. We could conclude that ________. a. fingerprints in twins are highly variable b. the first group of twins are monozygotic and the second group of twins are dizygotic c. heritability does not apply to twins d. TRC is almost totally under environmental control

answer

b. the first group of twins are monozygotic and the second group of twins are dizygotic

question

Twin studies used to estimate the heritability of obesity suggest that about ______% of the phenotypic variation in obesity is explained by genetic factors

answer

70%

question

The human gene for leptin, comparable to the mouse obesity gene ob, ________ a. helps regulate fat conversion and energy consumption in the body b. all of the choices c. is responsible for the majority of obesity cases in the human population d. is the only gene known to affect obesity in humans

answer

a. helps regulate fat conversion and energy consumption in the body

question

Which of the following statements about concordance is NOT true? a. Twins show concordance if both have a trait. b. In a trait completely controlled by genes, concordance in dizygotic twins should be 0.50. c. If heritability of a trait is high, there will be little difference in concordance between MZ and DZ twins. d. Concordance values can be converted to heritability values.

answer

c. If heritability of a trait is high, there will be little difference in concordance between MZ and DZ twins

question

Variants of genes that control salt and water retention, such as the gene for angiotensin (AGT), are associated with which of the following multifactorial traits? a. high levels of LDL lipoproteins b. atherosclerosis c. familial hypercholesteremia d. essential hypertension

answer

d. essential hypertension

question

Which of the following statements about cholesterol is NOT correct? a. HDLs are about 45% cholesterol and LDLs are about 20% cholesterol. b. An imbalance between dietary intake and the synthesis and breakdown of lipids such as cholesterols can result in atherosclerosis. c. The higher the HDL/total cholesterol ratio, the lower the risk of atherosclerosis. d. Familial hypercholesteremia is an autosomal disorder caused by defective LDL receptors.

answer

a. HDLs are about 45% cholesterol and LDLs are about 20% cholesterol.

question

Skin color is controlled by ________. a. genetic and environmental factors b. two gene pairs c. more than 70 gene pairs d. genetic factors only

answer

a. genetic and environmental factors

question

Intelligence is accurately measured by ________. a. phrenology b. intelligence quotient (IQ) c. none of the choices d. psychological tests

answer

c. none of the choices

question

The location of the centromere is characteristic for a specific chromosome. A chromosome whose centromere is placed very close to one end of the chromosome is termed ________.

answer

acrocentric

question

In order to create a karyotype for chromosome analysis, ________. a. chromosomes are partially digested with trypsin to enhance chromosome banding patterns b. chromosomes are stained with Giemsa to enhance chromosome visibility c. lymphocytes are treated with Colcemid to stop dividing cells at metaphase d. all of the choices

answer

d. all of the choices

question

The most common method of karyotype construction reveals a total of about 550 bands. Up to 2,000 bands can be revealed in the normal human karyotype by ________. a. using C-banding instead of G-banding b. using early metaphase or late prophase cells instead of metaphase cells c. using Q-banding instead of G-banding d. using chromosome painting to attach fluorescent dyes to specific DNA sequences

answer

b. using early metaphase or late prophase cells instead of metaphase cells

question

______ is defined as a chromosomal number that is a multiple of the normal haploid chromosome set.

answer

Polyploidy

question

A failure of the separation of one pair of homologous chromosomes in meiosis.

answer

nondisjunction

question

Most autosomal trisomies are lethal. Which autosomal trisomy allows survival into adulthood?

answer

trisomy 21

question

Which of the following statements about trisomy 21 (Down syndrome) is NOT correct? a. Down syndrome occurs in about 1 in 800 live births. b. Individuals who have Down syndrome are unable to live rich, productive lives. c. Individuals who have Down syndrome may have congenital heart defects and increased rates of respiratory infections and leukemia. d. Characteristics of Down syndrome include a wide, flat skull, folds in the corner of the eyelids, and spots on the iris.

answer

b. Individuals who have Down syndrome are unable to live rich, productive lives.

question

The only known risk factor for autosomal trisomy is ________.

answer

advanced maternal age

question

Turner syndrome and Klinefelter syndrome are two examples of ________. a. autosomal trisomy b. autosomal monosomy c. triploidy d. aneuploidy of the sex chromosomes

answer

d. aneuploidy of the sex chromosomes

question

In aneuploidy of the sex chromosomes, which of the following is considered lethal? a. 47, XXY b. 47, XYY c. 45, Y d. 45, X

answer

c. 45, Y

question

What conclusions can be drawn from the study of sex chromosome disorders? a. The addition of extra copies of either sex chromosome interferes with normal development. b. As the number of sex chromosomes in the karyotype increases, the phenotype becomes more severe. c. At least one copy of an X chromosome is essential for survival. d. All of the choices.

answer

d. All of the choices.

question

Which form of structural alteration within a chromosome does NOT change the amount of information carried by the chromosome, only the order? a. translocation b. inversion c. deletion d. duplication

answer

b. inversion

question

Which of the following statements about translocation is NOT correct? a. Robertsonian translocations can produce genetically unbalanced gametes with duplicated or deleted chromosomal segments. b. In a reciprocal translocation, no genetic information is gained or lost, just moved to a new location. c. Translocations move a chromosomal segment to a nonhomologous chromosome. d. Most Down syndrome cases involve a Robertsonian translocation.

answer

d. Most Down syndrome cases involve a Robertsonian translocation.

question

The consequences of aneuploidy include ________. a. all of the choices b. birth defects c. cancer d. spontaneous abortions

answer

a. all of the choices

question

Among the following four tests: CVS at 10 to 12 weeks, amniocentesis at 16 weeks, tests of stillbirths, and tests of live births, the highest frequency of chromosomal abnormalities are found ________ and the lowest frequency of chromosomal abnormalities are found ________. a. by amniocentesis, by CVS b. in stillbirths, in live births c. by CVS, in live births d. by CVS, by amniocentesis

answer

c. by CVS, in live births

question

Uniparental disomy has been diagnosed in rare cases of ________. a. females afflicted with rare X-linked disorders such as hemophilia b. all of the choices c. children affected with rare autosomal recessive disorders when only one parent is heterozygous d. father-to-son transmission of a rare, X-linked disorder when the mother is heterozygous normal

answer

b. all of the choices

question

Which of the following statements about fragile sites is NOT correct? a. Fragile sites are inherited as codominant traits. b. Fragile-X syndrome is associated with a form of mental retardation. c. Over 100 fragile sites have been identified in the human genome. d. Fragile sites are found only on X chromosomes.

answer

d. Fragile sites are found only on X chromosomes.

question

The male reproductive structure in which spermatogonia undergo meiosis and become sperm is the ________.

answer

seminiferous tubules

question

Which female reproductive structure contains a follicle?

answer

ovary

question

All of the ________ in the ovary remain in prophase of meiosis I until one develops and is released into the oviduct as ________ during ovulation.

answer

primary oocytes, a secondary oocyte

question

Fertilization normally occurs in the female ________.

answer

oviduct

question

What happens to the egg during fertilization? a. The entrance of the sperm into the egg reinitiates meiosis in the egg. b. All of the choices. c. A sperm binds to receptors on the surface of the egg. d. Fusion with a sperm triggers changes in the cell's outer membrane.

answer

b. All of the choices.

question

The trophoblast forms a two layered ________ which releases hCG to prevent breakdown of the endometrium and maintain pregnancy.

answer

chorion

question

Which of the following correctly describes the embryonic circulatory system? a. During the second month, the fetal heartbeat can be heard with a stethoscope. b. Maternal blood circulates through the embryo via the umbilical cord. c. Materials are exchanged between blood in the endometrium and blood in the placenta, which are separated by their membranes. d. The inner cell mass of the blastocyst eventually forms the placenta.

answer

c. Materials are exchanged between blood in the endometrium and blood in the placenta, which are separated by their membranes.

question

Between implantation and the fourth week of development, ________. a. all of the choices b. organ systems begin to take shape c. three basic tissue layers are formed d. much of the body is composed of paired segments

answer

a. all of the choices

question

Chemicals and other environmental agents that produce embryonic or fetal abnormalities are called ________.

answer

teratogens

question

The most widespread teratogenic problem and the leading preventable cause of birth defects is ________.

answer

alcohol

question

The chromosomal sex of a child is determined by ________ because ________. a. the mother, she is homogametic b. the father, he is heterogametic c. the mother, she is heterogametic d. the father, he is homogametic

answer

b. the father, he is heterogametic

question

During embryonic and fetal development, interactions with the environment, gene action, or other interactions can produce a phenotype ________. a. with characteristics and genitalia of both sexes b. opposite to the chromosomal sex c. intermediate to the phenotypes of the two sexes d. all of the choices

answer

d. all of the choices

question

Which of the following statements about gonadal sex differentiation is NOT correct? a. The SRY gene causes testes to develop. b. Müllerian inhibiting hormone (MIH) causes female ducts to develop. c. During the first 7 weeks, both male and female reproductive duct systems develop. d. Testosterone causes male ducts to develop.

answer

b. Müllerian inhibiting hormone (MIH) causes female ducts to develop.

question

A mutation in the X-linked gene AR (androgen receptor) ________. a. causes XY males to become phenotypic females b. causes XX females to become phenotypic males c. causes XY males to become phenotypic hermaphrodites d. causes XX females to become phenotypic hermaphrodites

answer

a. causes XY males to become phenotypic females

question

__________ equalizes the amount of X chromosome gene products in males and females.

answer

Dosage compensation

question

What is the relationship between X chromosomes and Barr bodies? a. Only one X chromosome is genetically active in the body cells of female mammals. b. Inactivated X chromosomes are tightly coiled to form Barr bodies. c. XY males have no inactive X chromosome and no Barr bodies. d. All of the choices.

answer

d. All of the choices.

question

Which of the following statements about calico cats is NOT true? a. Calico coat color is an autosomal recessive trait. b. Calico cats express a mosaic phenotype. c. All calico cats are heterozygous for coat color. d. All calico cats are female.

answer

a. Calico coat color is an autosomal recessive trait.

question

Which of the following is an example of X inactivation? a. A genetic variant in a male hormone receptor gene located on the X chromosome causes pattern baldness in adult men. b. An autosomal dominant trait affecting puberty is expressed in males but not in females. c. Duchenne muscular dystrophy affects 1 in 3,500 males and 1 in 50,000,000 females. d. In identical female twins, both heterozygous for an X-linked recessive trait (color blindness), one twin has the recessive phenotype while the other has the dominant phenotype.

answer

d. In identical female twins, both heterozygous for an X-linked recessive trait (color blindness), one twin has the recessive phenotype

question

Genes in which expression depends on whether it is inherited from the mother or from the father are called ________.

answer

imprinted genes

question

Which of the following describes the results of Griffith's experiments with Streptococcus pneumoniae? a. All of the choices. b. Mice injected with both heat-killed S cells and live R cells died. c. Mice injected with live R cells lived. d. Mice injected with live S cells died.

answer

a. All of the choices.

question

The experiments of Hershey and Chase showed that the ________ of the bacteriophage stays outside the bacterium and the ________ of the bacteriophage enters the bacterium. a. phosphorus-tagged protein coat, sulfur-tagged DNA b. sulfur-tagged DNA, phosphorus-tagged protein coat c. phosphorus-tagged DNA, sulfur-tagged protein coat d. sulfur-tagged protein coat, phosphorus-tagged DNA

answer

d. sulfur-tagged protein coat, phosphorus-tagged DNA

question

What building block of DNA is made up of a base, a sugar, and a phosphate group?

answer

nucleotide

question

The sugar ________ and the base ________ are found in the DNA molecule but not in the RNA molecule. a. deoxyribose, thymine b. pentose, uracil c. purine, pyrimidine d. ribose, uracil

answer

a. deoxyribose, thymine

question

Polynucleotide chains have a/an ________ at the 5' end and a/an ________ at the 3' end. a. OH group, phosphate group b. nitrogenous base, phosphate group c. phosphate group, OH group d. phosphate group, nitrogenous base

answer

c. phosphate group, OH group

question

What evidence did Watson and Crick use to construct a model of the structure of the DNA molecule? a. The DNA molecule has a helical shape with a constant diameter. b. The phosphate groups are on the outside of the helix. c. The amount of adenine in DNA equals the amount of thymine, and the amount of guanine equals the amount of cytosine. d. All of the choices.

answer

d. All of the choices.

question

In the DNA double helix, the nucleotides are oriented with the ________ on the outside, and the ________ on the inside. a. sugar and phosphate, bases b. nucleotides, proteins c. bases and sugar, phosphate d. purines, pyrimidines

answer

a. sugar and phosphate, bases

question

Which of the following is NOT one of the three important genetic properties explained by the Watson-Crick DNA model? a. The DNA molecule replicates during interphase. b. Genetic information is stored in the sequence of bases in DNA. c. The model offers a molecular explanation for mutation. d. The complementary strands can be used as a template for DNA replication.

answer

a. The DNA molecule replicates during interphase.

question

Which of the following is NOT one of the three main functions of RNA? a. RNA stores information in a double helix. b. RNA participates in the synthesis of proteins. c. RNA transfers genetic information from the nucleus to the cytoplasm. d. RNA is a component of ribosomes.

answer

a. RNA stores information in a double helix.

question

During interphase, chromosomes ________. a. unwind and become dispersed b. undergo replication c. express their genes d. all of the choices

answer

d. all of the choices

question

In the first stage of compaction, DNA coils around a DNA-binding protein to form a ________.

answer

nucleosome

question

What level of compaction is necessary for the DNA molecule to fit inside the nucleus?

answer

a factor of 5,000 to 10,000

question

The nucleus is organized into regions; each chromosome occupies a ________ separated by ________. a. chromosome territory, interchromosomal domains b. nucleolus, nuclear membrane c. locus, centromere d. nucleosome, histones

answer

a. chromosome territory, interchromosomal domains

question

DNA replication begins at ________ along the chromosome where ________ unwind the double helix for a short distance. a. hydrogen bonds, origins of replication b. origins of replication, multiprotein complexes c. nucleotides, hydrogen bonds d. multiprotein complexes, nucleotides

answer

b. origins of replication, multiprotein complexes

question

In DNA replication, which enzyme reads the sequence in the template strand and links complementary nucleotides together to form a new strand?

answer

DNA polymerase

question

The inability to produce an enzyme or other essential protein due to a mutation.

answer

inborn error of metabolism

question

What is the function of a protein? a. All of the choices. b. To act as hormones. c. To destroy invading microorganisms. d. To carry out biochemical reactions.

answer

a. All of the choices.

question

Proteins that catalyze biochemical reactions are called ________.

answer

enzymes

question

What is the major problem caused by phenylketonuria (PKU)? a. The defect in the enzyme converting phenylalanine to tyrosine causes a lack of tyrosine. b. The metabolic pathway to melanin production is blocked. c. High levels of phenylalanine and its metabolic by-products are produced during a time when the nervous system is developing. d. Homogentisic acid (HA) accumulates, causing the urine to turn black.

answer

c. High levels of phenylalanine and its metabolic by-products are produced during a time when the nervous system is developing.

question

If a woman who is homozygous for PKU, and who eats a normal diet, becomes pregnant, what is the effect on the fetus? a. The nervous system of the developing fetus will be affected no matter what the genotype. b. If the father is heterozygous, the chances are 50% that the fetus will be unaffected. c. The fetus will be unaffected no matter what the genotype. d. If the father is homozygous normal, the fetus will be heterozygous and unaffected.

answer

a. The nervous system of the developing fetus will be affected no matter what the genotype.

question

Which of the following is a polysaccharide which must be metabolized by enzymes? a. fructose b. galactose c. glucose d. glycogen

answer

d. glycogen

question

In galactosemia, which product in the metabolic pathway of lactose accumulates and reaches toxic levels in the body? a. UDP galactose b. galactose c. glucose d. galactose-1-phosphate

answer

d. galactose-1-phosphate

question

The decline in adult lactase levels (lactose intolerance) is inherited as ________. a. an X-linked trait b. an autosomal dominant trait c. a multiple-allele gene system d. an autosomal recessive trait

answer

d. an autosomal recessive trait

question

Proteins that act as signal receptors or transducers are usually found ________. a. embedded in the plasma membrane of the cell b. in hormones c. in the pathway of protein synthesis d. in mutated cells

answer

a. embedded in the plasma membrane of the cell

question

Which of the following statements about hemoglobin structure is NOT correct? a. Hemoglobin is composed of four protein molecules called globins. b. Each globin contains a heme group. c. Heme is an organic molecule containing an iron atom. d. There are four kinds of heme groups, each with a different function.

answer

d. There are four kinds of heme groups, each with a different function.

question

Genes for alpha globin and beta globin ________. a. all of the choices b. are grouped with pseudogenes c. are found on separate chromosomes d. are located in gene clusters with related genes

answer

a. all of the choices

question

More than ________ hemoglobin variants ________. a. 90% of all, are caused by substituting one amino acid for another b. 400, have been identified c. 60% of, are found in beta globin d. all of the choices

answer

d. all of the choices

question

Sickle cell anemia is caused by a single ________ mutation in the ________ gene. a. autosomal dominant, beta-globin b. autosomal recessive, beta-globin c. autosomal recessive, alpha-globin d. autosomal dominant, alpha-globin

answer

b. autosomal recessive, beta-globin

question

Disorders associated with an imbalance in the production of alpha and beta globin.

answer

Thalassemias

question

Patterns of globin gene expression change during development; at birth the ________ genes are switched off and the ________ genes are switched on. a. beta globin, gamma globin b. beta globin, alpha globin c. alpha globin, beta globin d. gamma globin, beta globin

answer

d. gamma globin, beta globin

question

Which of the following receptor-based senses is genetically determined? a. Some people can smell only red Verbena flowers and others can smell only pink Verbena flowers. b. All of the choices. c. Some people cannot smell the odor released by skunks. d. Some people can taste a bitter compound in broccoli and Brussels sprouts, others cannot.

answer

b. All of the choices.

question

In setting standards for safe exposure to organophosphate pesticides such as parathion, what factors must be considered? a. All of the choices. b. The amount of specific enzymes present in the cell. c. Genotype frequencies. d. Population differences in allele frequencies.

answer

a. All of the choices.

question

Mutation is the source of all ________ in humans and other organisms. a. genetic variation b. all of the choices c. diseases d. phenotypic variation

answer

a. genetic variation

question

In pedigree analysis, what characteristic may indicate that a dominant mutation has taken place? a. The phenotype appears after it is carried for many generations. b. The phenotype appears in males in a family with no known history of the condition c. A fully penetrant allele appears in a family with no previous history of the condition. d. A phenotype appears in one generation but not in the generation before or after.

answer

c. A fully penetrant allele appears in a family with no previous history of the condition.

question

What factor influences mutation rate? a. all of the choices b. nucleotide sequence c. size of the gene d. spontaneous chemical changes

answer

a. all of the choices

question

Mutation rates have been measured in achondroplasia, neurofibromatosis, and Huntington's disease because they all ________. a. have similar phenotypes b. are autosomal dominant disorders that are fully expressed c. have the same rates of mutation d. are autosomal recessive disorders that are fully expressed

answer

b. are autosomal dominant disorders that are fully expressed

question

What are the two main types of radiation?

answer

electromagnetic and corpuscular

question

Radiation often generates ________ by ________ which can produce mutations in DNA. a. millirems, producing standard amounts of x-rays b. ultraviolet (UV) light, producing ions c. free radicals, splitting water into hydrogen ions and hydroxyl radicals d. water, fusing hydrogen and oxygen

answer

c. free radicals, splitting water into hydrogen ions and hydroxyl radicals

question

Which of the following is NOT a mechanism by which chemicals may cause mutations? a. Intercalating agents can insert themselves into DNA, causing distortion of the double helix resulting in addition or deletion of a base pair. b. In transcription, the DNA base adenine (A) can pair with the RNA base uracil (U), eliminating thymine from the mRNA codon. c. Chemical mutagens attack the bases in a DNA molecule, changing one base into another. d. A base analog is inserted into DNA in place of thymine, leading to an A/T G/C mutation.

answer

b. In transcription, the DNA base adenine (A) can pair with the RNA base uracil (U), eliminating thymine from the mRNA codon.

question

A mutation which changes a single nucleotide, resulting in the substitution of one amino acid for another in a protein, is called a ________.

answer

missense mutation

question

________ produce longer-than-normal proteins and ________ produce shorter-than-normal proteins. a. Nonsense mutations, sense mutations b. Sense mutations, nonsense mutations c. Missense mutations, sense mutations d. Sense mutations, missense mutations

answer

b. Sense mutations, nonsense mutations

question

Which of the following statements about allelic expansion is NOT correct? a. Allelic expansion involves both alleles in a gene pair. b. The potential for allelic expansion is characteristic of a specific allele and occurs only within that allele. c. Allelic expansion is associated with trinucleotide repeats. d. Mutations that increase the number of trinucleotide repeats cause several genetic disorders.

answer

a. Allelic expansion involves both alleles in a gene pair.

question

In 20% to 50% of all cases of fragile X syndrome, ________. a. the FMR-1 allele contains 6 to 52 copies of the CGG repeat b. carrier mothers are affected with symptoms c. the mutant allele has a low degree of penetrance in males, and the phenotype is normal d. males carrying the premutation allele are affected with symptoms

answer

c. the mutant allele has a low degree of penetrance in males, and the phenotype is normal

question

Anticipation is related to degenerative disorders of the nervous system caused by trinucleotide expansion. Which of the following statements about anticipation is NOT correct? a. Genome instability such as trinucleotide expansion might explain genetic disorders that do not show simple Mendelian inheritance. b. Mildly affected parents have more seriously affected offspring. c. Offspring develop symptoms at an earlier age than their parents did. d. Genes are highly stable entities that undergo only occasional mutations.

answer

d. Genes are highly stable entities that undergo only occasional mutations.

question

Which of the following statements about spontaneous DNA mutations is NOT correct? a. DNA polymerase can move backward to proofread and correct errors in DNA replication. b. All spontaneous DNA mutations cause permanent genomic change. c. Spontaneous mutations can occur during DNA replication. d. If not repaired, spontaneous DNA damage could destroy much of the cell's DNA.

answer

b. All spontaneous DNA mutations cause permanent genomic change.

question

Thymine dimers ________. a. are caused by exposure to UV light (sunlight or tanning lamps) b. are a major cause of cell death, mutation, and cancer c. all of the choices d. distort the DNA molecule and interfere with normal replication

answer

c. all of the choices

question

The phenotype associated with many genetic disorders such as cystic fibrosis is caused by ________. a. frameshift mutations only b. a single nucleotide substitution in codon 6 c. a number of different mutations, or combinations of mutations, in a single gene d. splicing mutations only

answer

combinations of mutations, in a single gene

question

A person who carries two different mutations that produce an abnormal phenotype in the same gene is known as ________.

answer

a compound heterozygote

question

Different types and locations of mutations within the same gene ________. a. do not change the phenotypic expression of the genetic disorder b. can produce different genetic disorders c. can cause a wide range of different clinical symptoms for the same genetic disorder d. can balance the gene product back to its normal functional condition

answer

c. can cause a wide range of different clinical symptoms for the same genetic disorder

question

A difference in gene expression caused by a chemical modification which identifies a gene as coming from the mother or from the father is called ________.

answer

genomic imprinting

question

An epigenetic modification which changes from generation to generation.

answer

genomic imprinting

question

Cancer is initiated by ________. a. all of the choices b. environmental factors such as chemicals c. genetic mutations d. behavior such as smoking

answer

c. genetic mutations

question

The ability of cancer cells to detach from a primary tumor and move to new sites.

answer

metastasis

question

Genetic factors that contribute to the development of cancer include ________. a. all of the choices b. sporadic occurrence of a single dominant mutation in a somatic cell c. accumulation of a certain number of recessive mutations in a somatic cell d. a heritable predisposition to cancer

answer

a. all of the choices

question

Cancer cells are characterized by ________ and ________. a. uncontrolled cell division, abnormal shapes b. inability to divide, abnormal shapes c. uncontrolled cell division, inability to spread d. inability to divide, metastasis

answer

a. uncontrolled cell division, abnormal shapes

question

Genes that increase or decrease the rate of cell division regulate which checkpoints in the cell cycle? a. G1/S and G2/M b. M/G1 and S/G2 c. G1/S and S/G2 d. M/G1 and G2/M

answer

a. G1/S and G2/M

question

Which genes involved in regulating the cell cycle cause uncontrolled cell proliferation?

answer

oncogenes

question

In sporadic retinoblastoma, ________ cells carry copies of a mutant RB1 allele and ________ mutation(s) must occur in a single cell for cancer to develop. a. all retinal, two b. all body, one c. all retinal, one d. no body, two

answer

d. no body, two

question

The ras proto-oncogene family is involved in transmitting signals from ________ to ________. a. the RB1 gene, a retinal cell b. the G1 phase, the S phase of mitosis c. the plasma membrane, the cell nucleus d. the active state, the inactive state

answer

c. the plasma membrane, the cell nucleus

question

Women who inherit one mutant BRAC1 allele ________. a. have an increased risk for ovarian cancer b. all of the choices c. have a hereditary predisposition for breast cancer d. have a high risk of developing a mutation in the other BRAC1 allele

answer

b. all of the choices

question

The mutant form of the BRCA1 protein ________, which allows breast cancer to develop. a. is unable to repair DNA b. binds to Rap80 protein c. is activated when DNA is damaged d. stops DNA replication

answer

a. is unable to repair DNA

question

For colon cancer to develop, ________. a. two mutational steps are required b. a half-dozen or more mutations are required c. both alleles must be mutant d. only one of the two alleles must be mutant

answer

b. a half-dozen or more mutations are required

question

In FAP-associated colon cancer, the first step is a mutation in the ________ gene.

answer

APC

question

Mutations in MSH2 or MLH1 genes destabilize the genome, generating a cascade of mutations in DNA sequences called ________ that are ________. a. HNPCC, associated with defects in DNA repair b. microsatellites, repeated thousands of times and located on many chromosomes c. polyps, benign tumors d. FAP, adenoma formations

answer

b. microsatellites, repeated thousands of times and located on many chromosomes

question

________ genes control the cell cycle, and ________ genes encode proteins that maintain the integrity of the genome. a. Proto-oncogenes, oncogenes b. HNPCC, FAP c. Gatekeeper, caretaker d. BRCA1, BRCA2

answer

c. Gatekeeper, caretaker

question

Changes in ________ chromosomes are a common feature of cancer cells. a. structure of b. all of the choices c. genes in d. number of

answer

b. all of the choices

question

The Philadelphia chromosome (a reciprocal translocation between chromosome 9 and chromosome 22) is associated with ________. a. chronic myelogenous leukemia b. acute myeloblastic leukemia c. Burkitt's lymphoma d. multiple myeloma

answer

a. chronic myelogenous leukemia

question

A translocation such as the Philadelphia chromosome results in a ________ which causes leukemia. a. hybrid gene b. proto-oncogene c. C-ABL gene d. BCR gene

answer

a. hybrid gene

question

The drug Gleevec, developed to target cancerous CML cells, works by blocking the ________ which is required to ________. a. formation of the hybrid protein, prevent CML cells from dividing b. binding of ATP, form the hybrid protein c. binding of ATP, signal CML cells to divide d. formation of the hybrid protein, signal CML cells to divide

answer

c. binding of ATP, signal CML cells to divide

question

Epidemiology provides correlations between ________ and the existence of a disease such as cancer. a. environmental agents b. the three-dimensional structure of mutant gene products c. anticancer drugs d. the molecular organization of oncogenes

answer

a. environmental agents

question

Which of the following is a significant example of an environmental factor associated with cancer? a. Antibodies that bind to mutant proteins can be used to detect cancer at a very early stage. b. Lightly pigmented people are at much higher risk for skin cancer due to UV exposure than heavily pigmented individuals. c. In familial FAP-associated colon cancer, hundreds or thousands of polyps can develop. d. The hybrid BCR-ABL protein encodes an abnormal protein that constantly signals CML cells to divide.

answer

b. Lightly pigmented people are at much higher risk for skin cancer due to UV exposure than heavily pigmented individuals.

question

A polypeptide is the product of a single ________.

answer

gene

question

A codon is a series of three ________.

answer

RNA nucleotides

question

Which of the following statements about the genetic code is NOT correct? a. The same codons are used for the same amino acids in most living organisms. b. 61 codons code for the 20 amino acids found in proteins. c. The AUG codon has no known function. d. 3 different stop codons signal the end of protein synthesis.

answer

c. The AUG codon has no known function.

question

A gene is transcribed from ________ to ________, and translated into a series of ________. a. mRNA, DNA, nucleotides b. codons, nucleotides, proteins c. DNA, mRNA, codons d. DNA, mRNA, amino acids

answer

d. DNA, mRNA, amino acids

question

The structure and function of a human protein are determined by ________. a. which of the 20 amino acids are included in the protein b. the length of the amino acid chain c. the relative proportions of the 20 amino acids d. the specific sequence of its amino acids

answer

d. the specific sequence of its amino acids

question

Which of the following is NOT one of the three stages of transcription? a. translation b. termination c. initiation d. elongation

answer

a. translation

question

In the initiation of transcription, ________ binds to the promoter region of the ________. a. DNA polymerase, DNA molecule b. RNA polymerase, DNA molecule c. DNA polymerase, RNA molecucle d. RNA polymerase, RNA molecule

answer

b. RNA polymerase, DNA molecule

question

Nucleotide sequences within a gene that are transcribed but not translated into proteins are called ________.

answer

introns

question

In mRNA processing, ________. a. all of the choices b. introns are removed c. a poly-A tail is added to the 3' end d. a cap is added to the 5' end

answer

a. all of the choices

question

Ribosomes are ________. a. cytoplasmic organelles with two subunits b. composed of rRNA and proteins c. the site of protein synthesis d. all of the choices

answer

d. all of the choices

question

Which type of RNA is NOT correctly paired with its function? a. mRNA, contains a transcript of a gene which is transferred from DNA to ribosomes. b. rRNA, combines with proteins to form ribosomes. c. Pre-mRNA, binds to the promoter region on the DNA molecule. d. tRNA, carries specific amino acids to the ribosome.

answer

c. Pre-mRNA, binds to the promoter region on the DNA molecule.

question

The ________ of the tRNA molecule pairs with ________ molecule. a. codon, the anticodon on the mRNA b. anticodon, a specific amino acid c. codon, a specific amino acid d. anticodon, the codon on the mRNA

answer

d. anticodon, the codon on the mRNA

question

In translation, the initiation complex is composed of ________. a. a start codon, a small ribosomal subunit, and an mRNA strand b. a tRNA, a large ribosomal subunit, and an mRNA strand c. a tRNA, a small ribosomal subunit, and a polypeptide chain d. a tRNA, a small ribosomal subunit, and an mRNA strand

answer

d. a tRNA, a small ribosomal subunit, and an mRNA strand

question

Which of the following statements about the formation of a polypeptide chain is NOT correct? a. An enzyme forms a peptide bond between the codon and the anticodon. b. The first amino acid in the chain is always methionine. c. Ribosomes have two binding sites for tRNA molecules. d. Stop codons do not code for amino acids.

answer

a. An enzyme forms a peptide bond between the codon and the anticodon.

question

What happens to a polypeptide when it is released from the ribosome? a. All of the choices. b. Polypeptides folded in the ER are transported to the Golgi complex to be packaged for secretion. c. Polypeptides made on cytoplasmic ribosomes are folded and remain in the cell. d. Some polypeptides enter the ER, where they are folded and modified.

answer

a. All of the choices.

question

The function of a protein is ultimately determined by its ________. a. codons b. sequence of nucleic acids c. proteome d. DNA-controlled primary structure

answer

d. DNA-controlled primary structure

question

A protein folded into an infectious conformation.

answer

prion

question

Which method of cloning farm animals such as cattle and sheep fuses an embryonic cell with an enucleated egg? a. nuclear injection b. embryo splitting c. nuclear transfer d. twinning

answer

c. nuclear transfer

question

A new method used to clone animals directly injects ________ into ________. a. cells from early embryos, a callus b. cells from early embryos, enucleated eggs c. sperm, egg cells d. nuclei from adult cells, enucleated eggs

answer

d. nuclei from adult cells, enucleated eggs

question

Which of the following is NOT one of the three main requirements for cloning DNA? a. A method for removing DNA from egg cells. b. A place where the DNA can be copied. c. A carrier molecule to hold the DNA for cloning. d. A way to consistently cut the DNA at specific sites.

answer

a. A method for removing DNA from egg cells.

question

Restriction enzymes cut DNA at specific sites, creating ________. a. DNA ligase b. single-stranded tails c. vectors d. restriction endonucleases

answer

b. single-stranded tails

question

DNA fragments from different sources can associate together by ________ and be linked by ________ to form recombinant DNA molecules. a. embryo spitting, nuclear transfer b. restriction enzymes, vectors c. covalent bonds, hydrogen bonds d. base pairing, DNA ligase

answer

d. base pairing, DNA ligase

question

A fragment of DNA cut with a restriction enzyme can be linked ________. a. only with DNA from the same type of organism b. only with other DNA cut with the same restriction enzyme c. only with a restriction enzyme d. with any DNA that has sticky ends

answer

b. only with other DNA cut with the same restriction enzyme

question

Bacterial plasmids are ________. a. small, circular DNA molecules b. vectors used to transfer foreign DNA segments between host cells c. all of the choices d. carrier molecules for DNA to be cloned

answer

c. all of the choices

question

Which of the following is the correct order of steps in DNA cloning? a. A restriction enzyme is added to DNA and plasmids, DNA fragments and cut vectors are mixed, DNA ligase is added, plasmid vectors are placed in bacterial cells. b. DNA fragments and cut vectors are mixed, DNA ligase is added, plasmid vectors are placed in bacterial cells, a restriction enzyme is added to DNA and plasmids. c. DNA fragments and cut vectors are mixed, a restriction enzyme is added to DNA and plasmids, DNA ligase is added, plasmid vectors are placed in bacterial cells. d. A restriction enzyme is added to DNA and plasmids, plasmid vectors are placed in bacterial cell, DNA fragments and cut vectors are mixed, DNA ligase is added.

answer

a. A restriction enzyme is added to DNA and plasmids, DNA fragments and cut vectors are mixed, DNA ligase is added, plasmid vectors are placed in bacterial cells.

question

When using antibiotic-resistance markers to find bacterial colonies carrying human DNA fragments, researchers looked for colonies that ________. a. would grow on plates with ampicillin but not on plates with tetracyclin b. would grow on plates with ampicillin and on plates with tetracyclin c. would not grow on plates with ampicillin or on plates with tetracyclin d. would grow on plates with tetracyclin but not on plates with ampicillin

answer

a. would grow on plates with ampicillin but not on plates with tetracyclin

question

Which type of cloned genetic library carries all of the genes of an individual?

answer

a genomic library

question

To find a specific gene in a genomic library of over 20,000 genes, ________ is/are used.

answer

a nuclear probe

question

In order for a radioactive probe to identify a particular colony of DNA among many colonies on a plate, the DNA must FIRST be ________. a. denatured to single strands b. transcribed onto mRNA c. separated by gel electrophoresis d. exposed to x-ray film to reveal the location of the colony

answer

a. denatured to single strands

question

What method can be used to produce millions of copies of a single DNA molecule in a short period of time? a. gel electrophoresis b. polymerase chain reaction c. radioactive probe d. Southern blot

answer

b. polymerase chain reaction

question

Information obtained through PCR techniques is used to ________. a. identify products made from extinct or endangered animals b. identify dried blood in forensic applications c. all of the choices d. study how specific genes have changed over long stretches of evolutionary time

answer

c. all of the choices

question

In electrophoresis, when DNA fragments are separated by passing an electrical current through the gel, the fragments that ________ move the farthest. a. have a negative charge b. are the largest c. have a positive charge d. are the smallest

answer

d. are the smallest

question

In the Southern blot procedure, DNA fragments separated by gel electrophoresis are ________. a. transferred to a sheet of DNA-binding membrane b. hybridized with radioactive probes c. converted to single strands d. all of the choices

answer

d. all of the choices

question

An automated version of the Sanger method of DNA sequencing uses ________ to analyze genes. a. Southern blotting b. a radioactively labeled single-stranded probe c. altered nucleotides with fluorescent tags d. restriction enzymes

answer

c. altered nucleotides with fluorescent tags

question

Individuals with genetic disorders such as hemophilia or type I diabetes ________. a. can be treated with purified proteins produced by recombinant DNA technology b. all of the choices c. used to be exposed to serious and potentially fatal risks when treated with proteins collected from many sources d. are unable to make certain proteins such as clotting factor or insulin

answer

b. all of the choices

question

A rabbit which carries a human gene that causes it to produce a human enzyme in its milk is a ________.

answer

transgenic organism

question

Crop plants can be genetically modified by ________. a. hybridization b. recombinant DNA technology c. artificial selection d. all of the choices

answer

d. all of the choices

question

Which of the following is a concern about the use of transgenic plants? a. The possibility of disease-causing bacteria acquiring antibiotic-resistance genes used as transgenic markers. b. The hybridization of transgenic plants with wild plants of the same species. c. All of the choices. d. The safety of eating food containing parts of viral genes.

answer

c. All of the choices.

question

To make a transgenic HD mouse, a copy of the mutant human HD gene was cloned into a vector, and the vector was ________. a. microinjected into the cells of adult transgenic mice b. implanted into a transgenic mouse c. implanted into a foster mother mouse d. microinjected into the nucleus of a fertilized mouse egg

answer

d. microinjected into the nucleus of a fertilized mouse egg

question

Transgenic HD mice are being used to study ________. a. progressive destruction of brain structures b. all of the choices c. links between changes in brain structure and behavior d. drugs to improve symptoms or reverse brain damage

answer

b. all of the choices

question

The most specific and sensitive method of identifying a genetic disease or susceptibility carried by an individual is ________. a. recombinant DNA technology b. chorionic villus sampling c. amniocentesis d. karyotyping

answer

a. recombinant DNA technology

question

Which of the following prenatal tests can be used for genetic screening before an egg is fertilized? a. polar body biopsy b. chorionic villus sampling c. amniocentesis d. blastomere testing

answer

a. polar body biopsy

question

Prenatal genetic testing is not universally effective at detecting ________. a. X-linked traits such as hemophilia b. Down syndrome c. cystic fibrosis d. sickle cell anemia

answer

c. cystic fibrosis

question

Presymptomatic testing is typically used to detect ________. a. dominantly inherited disorders that develop in adulthood b. X-linked disorders in males c. all dominantly inherited disorders d. potentially fatal homozygous recessive disorders

answer

a. dominantly inherited disorders that develop in adulthood

question

A DNA ________ can be used to screen a person's entire genome for mutations, and can identify mutations in single nucleotides.

answer

microarray

question

Some normal DNA is tagged with a green fluorescent probe, some DNA to be tested is tagged with a red fluorescent probe, and both are added to a DNA microarray to test for mutations. Some dots on the microarray stay black because ________. a. a mutation has been detected b. only the test DNA is bound to that field c. neither tagged DNA is bound to that field d. only the normal DNA is bound to that field

answer

c. neither tagged DNA is bound to that field

question

Nucleotide sequences 2 to 9 base pairs long, organized into clusters of varying lengths, which are used in the construction of DNA profiles are called ________.

answer

short tandem repeats

question

A DNA profile can be constructed ________. a. from very old samples of DNA b. which is unique to the individual c. all of the choices d. from a single hair

answer

c. all of the choices

question

In analyzing a DNA profile, STR alleles are identified and ________. a. the number of STRs in each allele are counted and added together b. the population frequencies for all the alleles are multiplied together c. one allele is selected for nucleotide sequencing d. the number of heterozygous alleles are counted and added together

answer

b. the population frequencies for all the alleles are multiplied together

question

Which of the following is an ethical issue raised by biotechnology? a. The identification of progressive and fatal genetic disorders for which there is no treatment. b. The use of identifying labels on foods genetically modified by recombinant-DNA technology. c. The use of recombinant-DNA produced hormones to improve athletic performance. d. All of the choices.

answer

d. All of the choices.

question

In a study of pedigrees, researchers determined that blood type B and the autosomal dominant condition nail-patella syndrome were inherited together. They concluded that ________. a. the two conditions must always be inherited together b. the genes were not linked c. both conditions were caused by the same gene d. both genes must be located on the same chromosome

answer

d. both genes must be located on the same chromosome

question

The distance between two genes on the same chromosome was first measured by ________. a. electron microscopy b. calculating how often they recombine by crossing over c. gel electrophoresis d. counting the number of mutated alleles

answer

b. calculating how often they recombine by crossing over

question

A ________ is the ratio of probabilities that two genes are linked to the probability that they are not linked, expressed as a log10.

answer

LOD score

question

Positional cloning uses markers in cloned DNA sequences to ________ with no prior information about the gene function. a. map genes on chromosomes b. calculate lod scores c. produce vectors d. determine mutation rates

answer

a. map genes on chromosomes

question

Which of the following methods is used in the modern practice of genomics? a. Software to collect, analyze and store information from genome sequencing. b. Automated methods of DNA sequencing. c. All of the choices. d. The creation of web-based databases and research tools.

answer

c. All of the choices.

question

Which of the following emerging genetic fields is NOT correctly identified? a. Comparative genomics: A comparison of functions among various different human genes. b. Structural genomics: Derives three-dimensional structures for proteins. c. Pharmacogenomics: Analyzes genes and proteins to identify targets for therapeutic drugs. d. Bioinformatics: The use of computers and software to acquire, store, and analyze genomic information.

answer

a. Comparative genomics: A comparison of functions among various different human genes.

question

The human genome contains ________. a. over 3 billion genes b. over 3 billion nucleotides c. about 26,000 nucleotides d. about 1,000 genes

answer

b. over 3 billion nucleotides

question

In the clone-by-clone method of genome sequencing, ________, and in the shotgun method ________. a. clones are placed in order then sequenced, clones are sequenced then placed in order b. clones are selected at random, clones are selected in order c. genomes are sequenced before clones are selected, genomes are sequenced after clones are selected d. a physical map is not made, a physical map is made first

answer

a. clones are placed in order then sequenced, clones are sequenced then placed in order

question

Which of the following statements about the public and/or private human genome projects is NOT correct? a. Humans are the first species to have its genome sequenced. b. The government-sponsored genome project used the clone-by-clone method. c. The privately-funded genome project used the shotgun method. d. Both groups published an incomplete version of the human genome in 2001.

answer

a. Humans are the first species to have its genome sequenced.

question

The process of annotation identifies genomic nucleotide sequences that code for ________. a. non-protein-coding genes b. gene regulatory sequences c. all of the choices d. protein-coding genes

answer

c. all of the choices

question

After a gene has been identified by annotation, its ________ is derived and compared with known protein sequences in order to determine ________. a. control sequence, if it is active b. nucleotide sequence, the size of the gene c. heterochromatin sequence, the function of the gene d. amino acid sequence, the function of the gene

answer

d. amino acid sequence, the function of the gene

question

Which of the following statements about known features of the human genome is NOT correct? a. We share about half our genes with the fruit fly Drosophila. b. Genes are distributed equally along chromosomes. c. There are many more different proteins in the human body than there are genes. d. Only about 5% of our DNA encodes genetic information.

answer

b. Genes are distributed equally along chromosomes.

question

What new knowledge about genetic processes has emerged from the human genome projects? a. A new mechanism of mutation, trinucleotide expansion, has been identified. b. Some mutations in DNA repair genes can destabilize distant regions of the genome, making them susceptible to more mutations. c. All of the choices. d. Mutations in a single gene can give rise to several different genetic disorders.

answer

c. All of the choices.

question

Which of the following is NOT one of the three important questions that must be answered when studying any genetic disorder? a. What is the normal function of the protein encoded by the gene? b. How does the mutant gene or protein produce the disease or phenotype? c. What sequences mark control regions at the beginning of the gene? d. Where is the gene located?

answer

c. What sequences mark control regions at the beginning of the gene?

question

In studying the gene for cystic fibrosis, researchers first located the gene by ________, then determined its function by ________. a. positional cloning, searching protein databases for similar amino acid sequences b. positional cloning, analyzing the gene product in the laboratory c. the clone-by-clone method, analyzing the gene product in the laboratory d. the clone-by-clone method, searching protein databases for similar amino acid sequences

answer

a. positional cloning, searching protein databases for similar amino acid sequences

question

In the investigation of Friedreich ataxia (FRDA), researchers were able to quickly discover the ________ but not ________. a. location of the FRDA gene, the structure of the frataxin protein b. the structure of the frataxin protein, its amino acid sequence c. location of the FRDA gene, its nucleotide sequence d. the structure of the frataxin protein, its specific function

answer

d. the structure of the frataxin protein, its specific function

question

What is the role of proteomics in the field of genomics? a. Understanding gene function and its changing role in development and aging. b. All of the choices. c. Identifying proteins that are biomarkers for diseases. d. Finding proteins that are targets for the development of drugs to treat diseases and genetic disorders.

answer

b. All of the choices.

question

Which of the following is NOT one of the three leading causes of fertility problems in men? a. low motility b. hormonal imbalances c. low sperm count d. blocked ducts

answer

b. hormonal imbalances

question

Preimplantation genetic diagnosis (PGD) is performed ________. a. before an egg is fertilized by IVF b. when an IVF embryo is a few days old c. on the egg immediately after fertilization d. before the embryo is implanted into the oviduct

answer

b. when an IVF embryo is a few days old

question

Embryonic stem cells (ESC) are derived from the ________ in early mammalian embryos. a. trophoblast b. inner cell mass c. differentiated cells d. endometrial cells

answer

b. inner cell mass

question

Which form of gene therapy would change the genome of members of future generations? a. germ-line gene therapy b. enhancement gene therapy c. somatic gene therapy d. all of the choices

answer

a. germ-line gene therapy

question

Athletes have been suspended from competitions for using ________. a. erythropoietin (EPO), a hormone that increases the production of red blood cells b. hydration by intravenous fluids c. Repoxygen, a form of gene doping which turns on the EPO gene, increasing the production of red blood cells d. all of the choices

answer

a. erythropoietin (EPO), a hormone that increases the production of red blood cells

question

Conditions that involve ________ can be more difficult for genetic counselors to assess. a. autosomal recessive inheritance b. X-linked recessive inheritance c. autosomal dominant inheritance d. polygenic inheritance

answer

d. polygenic inheritance

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