Unit 3 Practice Problems

Unit 3 Practice Problems

_____1. The cell formed through fertilization is called a(n)
a) gamete b) sperm cell c) zygote d) egg cell e) ovum

_____2. If a sperm cell contains 8 chromosomes, it comes from an animal that has ____ chromosomes.
a) 4 b) 8 c) 12 d) 16 e) 24

_____3. The haploid cells produced by meiosis in plants Next become
a) gametes b) spores c) adult haploid plants d) adult diploid plants

_____4. Another name for a tetrad is a(n)
a) homologue b) bivalent c) oocyte d) gamete e) polar body

_____5. During which stage of meiosis does crossing over occur?
a) prophase I b) anaphase I c) telophase I d) prophase II e) anaphase II

_____6. What is the importance of crossing over?
a) It provides extra genetic material for the daughter cells.
b) It increases the likelihood that daughter cells contain different genetic material.
c) It increases chromosome condensation.
d) It separates the homologous chromosomes.

_____7. A synaptonemal complex is
a) the internal structure of nucleoprotein that make up a chromosome
b) a nucleoprotein lattice that forms between homologues in chiasmata
c) the spindle fibers that attach to homologous chromosomes during meiosis
d) the spindle fibers that attach from pole to pole without binding chromosomes
e) the set of cells produced from a single original parent cell in oogenesis

_____8. What does the term "chiasma" refer?
a) the process of fertilization
b) the process of crossing over
c) a structure that holds together homologues during crossing over
d) the period between meiosis I and meiosis II

_____9. During which stage of meiosis are the bivalents arranged along the equator?
a) prophase I b) metaphase II c) anaphase II d) prophase II e) metaphase I

_____10. At which stage of meiosis is each chromosome composed of a single chromatid?
a) prophase I b) anaphase II c) anaphase I d) prophase II e) metaphase I

_____11. During which stage of meiosis does the homologue separation occur?
a) prophase I b) anaphase I c) telophase I d) anaphase II e) metaphase I

_____12. Which stage of meiosis may not be present in some species?
a) prophase I b) anaphase I c) telophase I d) anaphase II e) prophase II

_____13. The events of meiosis II are most similar to
a) mitosis b) meiosis I c) interphase d) interkinesis

_____14. The term based on the Latin and Greek root words meaning "seed" and "production" is
a) gametogenesis b) oogenesis c) pangenesis d) spermatogenesis

_____15. Which statement is Not true about homologues in meiosis I?
a) Homologous chromosomes pair to form a tetrad.
b) Homologous chromosomes separate and go to different daughter cells.
c) Each homologue's chromosome splits to form two chromosomes.
d) Homologues exchange genetic material between non sister chromosomes.
e) Homologues interact with the spindle as if they were one chromosome.

_____16. Interkinesis is different from interphase in which way?
a) Interkinesis occurs after a cell finishes a nuclear division.
b) Interkinesis is the stage that proceeds a prophase stage.
c) Interphase involves DNA replication and interkinesis does not.
d) Interkinesis can be variable in length.

_____17. Which does Not occur in meiosis?
a) two daughter cells at completion c) four daughter cells at completion
b) two nuclear divisions d) formation of bivalents

_____18. Which is Not true about daughter cells of mitosis and meiosis?
a) In meiosis, daughter cells are haploid.
b) In meiosis, there are four daughter cells.
c) In mitosis, there are two daughter cells.
d) In mitosis, the daughter cells are genetically identical.
e) In meiosis, the daughter cells are genetically identical.

_____19. Meiosis leads to all the following Except
a) gametogenesis b) oogenesis c) pangenesis d) spermatogenesis

_____20. The polar body is
a) another name for an egg cell.
b) a precursor cell that becomes an egg cell.
c) a nonfunctional cell rudiment made at that same time as an egg cell.
d) the cell produced when fertilization occurs.

_____21. Why do polar bodies form?
a) They nurse the egg as it leaves the follicle.
b) This is extra chromosomal material representing the X chromosome in each female cell.
c) They orient the sperm toward the egg.
d) They allow a reduction in chromosomes while preserving all the food for one egg.
e) They orient the egg for penetration by the sperm.

_____22. Although sperm and egg are both produced by the process of meiosis, they differ
a) from a genetic point of view. each gene stands an equal chance of ending up in a sperm but has a 50%
chance of being discarded in the polar body in egg production.
b) in the allocation of cellular food supply.
c) in mortality.
d) All of these above are correct.

_____23. Which of the following is/are true about sexual reproduction?
a) At the cellular level is the opposite of reproduction since it involves two cells fusing to become one.
b) It requires the development of organs such as the uterus, which are of no immediate survival advantage to the
individual but are advantageous to the species.
c) It regularly produces a wider array of adaptations to the external environment in a shorter period of time.
d) It regularly produces a wider array of adaptations to the internal environment in a shorter period of time.
e) All of these are true.

_____24. Species X reproduces by fission and species Y reproduces sexually. Consider that all other relevant
characteristics are similar between the species. When the environment gradually changes, then
a) species X and Y will have an equal chance of surviving.
b) species Y should have a better chance of surviving than species X.
c) species X should have a better chance of surviving than species Y.
d) neither species should have an advantage in surviving since organisms often become extinct when the
environment changes.

_____25. Which of the following statements is True about a human meiotic cell after it has completed meiosis I?
a) It is diploid (2n).
b) It is haploid (n).
c) It has divided into four daughter cells.
d) It proceeds directly to meiosis II without an intervening intermission.

_____26. Spermatogenesis results in
a) four haploid cells
b) one haploid cell and three polar bodies
c) four diploid cells
d) to sperm cells and two polar bodies

_____27. Which of the following organisms is diploid (2n) only as a zygote and is haploid for every other part of its life cycle?
a) Humans b) Bryophytes c) Fungi d) Bacteria e) Angiosperms

_____28. During meiosis in the human male, the diploid cell gives rise to ____ haploid cells and ____ chromosomes in each cell.
a) 2, 46 b) 2, 23 c) 4, 23 d) 4, 46 e) 8, 92

_____29. Which statement best describes the process of crossing over?
a) It takes place between sister chromatids and results in new gene combinations.
b) It takes place between nonhomologous chromosomes and results in increased gene combination.
c) It takes place between homologous chromosomes and results in increased gene combination.
d) It takes place between homologous chromosomes and results in increased mutation rate.
e) It takes place between nonhomologous chromosomes and results in new gene combination.

_____30. The exchange of segments of chromatids during synapsis is known as
a) cross linkage b) sex linkage c) gene linkage d) crossing over e) nondisjunction

_____31. Imagine an organism whose 2n = 96. Meiosis would leave this organism's cells with how many chromosomes?
a) 192 b) 96 c) 48 d) 24 e) 23

_____32. Crossing over occurs during
a) prophase of mitosis
b) prophase I of meiosis
c) prophase II of meiosis
d) prophase I and II of meiosis
e) All of the above.

_____33. The moving apart of each pair of homologous chromosomes during anaphase I of meiosis is called
a) duplication b) crossing over c) disjunction d) replication e) synapsis

_____34. Chromosomes that are Not identified as sex chromosomes are called
a) autotrophs b) heterosomes c) autosomes d) chromatins e) chromatids

_____35. Which of the following events occurs during a synapsis?
a) randomly separating the maternal and paternal chromosomes
b) replication of the DNA
c) mixing half the maternal chromosomes with half the paternal chromosomes
d) pairing of homologues
e) appearance of spindle fibers

_____1. What aspect of Mendel's background gave him the necessary tools to discover the laws of inheritance?
a) He was a monk.
b) He was a teacher.
c) He lived in Austria.
d) He had studied mathematics and probability.
e) He corresponded with Charles Darwin.

_____2. What is the blending theory of inheritance?
a) Mendel's theory of how the traits of parents are passed to offspring through gametes.
b) Darwin's theory of how traits are passed from all parts of the parent's body into gamete to be transmitted to
the offspring.
c) the modern theory of how genetic information is passed from parents to offspring.
d) an old theory that said that the offspring show traits intermediate between those of parents.

_____3. Which characteristic of pea plants was Not important in their selection as Mendel's research organism?
a) Most other scientists of the time were also using peas, so a lot was known about them.
b) Peas are easy to cultivate.
c) Pea plants have a short generation time.
d) Pea plants are self pollinating but can be cross fertilized easily.

_____4. In a Mendelian monohybrid cross, which generation is always completely heterozygous?
a) F1 generation b) F2 generation c) F3 generation d) P generation

_____5. In a Mendelian monohybrid cross, which generation is always completely homozygous?
a) F1 generation b) F2 generation c) F3 generation d) P generation

_____6. If a pea plant shows a recessive phenotype?
a) it can be either TT or tt.
b) it can be either Tt or tt.
c) it can only be TT.
d) it can only be tt.
e) it can be TT, Tt, or tt.

_____7. The symbol "F" in the results of a testcross stands for
a) dominant
b) recessive
c) first trait to show up
d) "faulty" or unexpected results
e) filial

_____8. The F2 offspring of a monohybrid cross would show the genotype(s)
a) AA and Aa b) Aa and aa c) AA, Aa, and aa d) AA only e) Aa only

_____9. The F1 offspring of a monohybrid cross would show the genotype(s)
a) AA and Aa b) Aa and aa c) AA, Aa, and aa d) AA only e) Aa only

_____10. The offspring of a monohybrid testcross would show the genotype(s)
a) AA and Aa b) Aa and aa c) AA, Aa, and aa d) AA only e) Aa only

_____11. In which kind of cross would you expect to find a ration of 3.1 among the F2 offspring?
a) monohybrid cross b) dihybrid cross c) test cross d) None of the above.

_____12. Which is Not true according to Mendel's law of segregation?
a) Each individual contains two factors for each trait.
b) One factor must be dominant and one factor recessive in each individual.
c) Factors separate from each other during gamete formation.
d) Each gamete contains one copy of each factor.
e) Fertilization restores the presence of two factors.

_____13. A reciprocal cross would be
a) between a homozygous recessive individual and a homozygous dominant one with respect to one pair of traits.
b) between a homozygous recessive individual and a homozygous dominant one with respect to two pairs of traits.
c) between a homozygous recessive male and a homozygous dominant female, and a separate cross between
a homozygous dominant male and a homozygous recessive female.
d) self fertilization of an F2 plant.
e) self fertilization of an F1 plant

_____14. If you had two guinea pigs of opposite sex, both homozygous, one black and one brown, but you didn't know
which was the dominant characteristic, how would you find out the dominant color?
a) Mate them together and see what color the offspring are - that will be the dominant color.
b) Mate them together and see what color the offspring are - the other will be the dominant color.
c) Mate them together, then mate their offspring to see what color the grandchildren are - that will be the
dominant color.
d) Mate them together, then mate their offspring to see what color the grandchildren are - the other color will be
the dominant color.

_____15. The Greek root word for allele means
a) gene b) hereditary c) mathematical d) parallel or reciprocal e) different

_____16. What are alleles?
a) genes for different traits, such as hair color or eye color.
b) alternative forms of a gene for a single trait, such as blue eyes or brown eyes.
c) the location of genes on a chromosome
d) recessive forms of a kind of characteristic carried by genes.
e) dominant forms of a kind of characteristic carried by genes.

_____17. In which kind of cross would you expect to find exactly the anticipated ration every time the cross is made?
a) monohybrid cross b) dihybrid cross c) test cross d) None of above.

_____18. Mendel obtain plants that were pure for particular traits by
a) growing plants from the seeds of other plants that showed that trait.
b) discarding plants that showed other traits.
c) allowing plants to self pollinate for several generations.
d) allowing plants to cross pollinate for one generation.

_____19. When Mendel crossed a strain of tall pea plants with a strain of short pea plants, he observed that all the
plants in the F1 generation were tall. This suggest that
a) the tall was controlled by a dominant trait.
b) the short was controlled by a dominant trait.
c) both traits were controlled by a recessive trait.
d) the strain of short pea plants was not capable of pollinating the strain of tall plants.

_____20. When alleles for different characteristics as on separate chromosomes, they are distributed to gametes
independently. This observation is summarized by the law of
a) cross pollination b) independent assortment c) segregation d) molecular genetics

_____21. The appearance of an organism is its
a) genotype b) phenotype c) genotype ration d) phenotype ratio

_____22. In a dihybrid cross between an individual with the genotype RRYY and an individual with the genotype rryy,
all of the offspring will have the genotype
a) RRYY b) RrYY c) RrYy d) rryy e) rrYY

_____23. A heterozygous individual would have the following genotype.
a) pp b) YY c) Zz

_____24. Segregation of alleles occurs during
a) mitosis b) meiosis c) fertilization d) pollination

_____25. If two parents with dominant phenotypes produce an offspring with a recessive phenotype, then probably
a) both parents are heterozygous c) one parent is heterozygous
b) both parents are homozygous d) one parent is homozygous

_____26. Mendel called a trait that did Not show in a hybrid a(n)
a) parental trait b) codominant trait c) dominant trait d) recessive trait

_____27. What are different versions of a gene for the same trait?
a) alleles b) phenotypes c) dihybrid d) pure breeds

_____28. The law of segregation states that, during meiosis, each pair of alleles
a) stick together b) is tripled c) separates d) becomes pure bred

_____29. An allele that expresses itself in a hybrid is a(n)
a) recessive allele b) independent assortment c) allele pair d) dominant allele

_____30. The law of independent assortment states what?
a) Gene pairs sort randomly and independently from each other.
b) Gene pairs sort always in the same order.
c) Half of an organism's gametes have one allele per pair.
d) One allele is always dominant.

_____31. The actual genetic makeup of an organism is called its
a) phenotype b) homozygous type c) heterozygous type d) genotype

_____32. An organism in which two alleles for a trait are different is
a) heterozygous b) homozygous c) genotypic d) phenotypic

_____33. Punnett squares are grids that show
a) the phenotype of offspring
b) actual results of a genetic cross
c) all possible results of a genetic cross
d) only dihybrid crosses

_____34. Mendel obtain this P generation by allowing the plants to
a) self pollinate b) cross pollinate c) assort independently d) segregate

_____35. The phenotype of an organism
a) represents its genetic composition
b) reflects all the traits that are actually expressed
c) occurs only in dominant pure organisms
d) cannot be seen

_____36. If an individual possesses two recessive alleles for the same trait, the individual is said to be
a) homozygous for the trait b) haploid for the trait c) heterozygous for the trait d) mutated

_____37. A genetic trait that appears in every generation of offspring is called
a) dominant b) phenotypic c) recessive d) superior

_____38. The law of segregation states that
a) alleles of a gene separate from each other during meiosis
b) different alleles of a gene can never be found in the same organism
c) each gene of an organism ends up in a different gamete
d) each gene is found on a different molecule of DNA

_____39. The difference between a monohybrid cross and dihybrid cross is that
a) monohybrid crosses involve traits for which only one allele exists, while dihybrid traits involve two alleles.
b) monohybrid crosses involve self pollination, while dihybrid crosses involve cross pollination
c) monohybrid crosses involve one gene, dihybrid crosses involve two genes.
d) dihybrid crosses require two Punnett squares, monohybrid crosses need only one.

_____40. A cross of two individuals for a single contrasting trait is called
a) monohybrid b) dihybrid c) dominant d) codominant

_____41. Which of the following best describes the parents in a testcross?
a) One individual has the dominant phenotype and the other has the recessive phenotype.
b) Both individuals are heterozygous.
c) Both individuals have a dominant phenotype.
d) Both individuals have the recessive phenotype.
e) Both individuals have an unknown phenotype.

_____42. If "A" represents a dominant allele and "a" represents the recessive allele, what are the genotypes of the
parents that produce 300 progeny with the dominant gene and 100 progeny with the recessive gene?
a) AA x AA b) AA x Aa c) AA x aa d) Aa x aa e) Aa x Aa

_____43. In peas the trait for tall plants is dominant (T) and the trait for short plants is recessive (t). The trait for yellow
seed color is dominant (Y) and the trait for green seed color is recessive (y). A cross between two plants results in 296 tall
yellow plants and 104 tall green plants. Which of the following are most likely to be the genotypes of parents?
a) TTYY x TTYY
b) TTyy x TTYy
c) TtYy x TtYy
d) TtYy x TTYy
e) TtYY x Ttyy

_____44. In horses, chestnut coat is dominant to black coat, and trotting gait is dominant to pacing. A horse that was hybrid
for both traits would have the genotype CcTt. If a horse who is a chestnut pacer is bred several times to a black trotter, and
they always have chestnut trotters and black trotters, what are the genotypes of the parents?
a) CcTT x ccTT
b) CcTt x ccTt
c) CCTT x Cctt
d) Cctt x ccTT
e) Cctt x ccTt

_____45. Alternative versions of the same gene are called
a) copies b) replicates c) homologues d) alleles e) rads

_____46. When an organism has two copies of the same allele it is said to be
a) homozygous b) heterozygous c) hemizygous d) zygotic e) replicative

_____47. When an organism has two different alleles of the same gene it is said to be
a) homozygous b) heterozygous c) hemizygous d) zygotic e) replicative

_____48. Different alleles
a) are alternative versions of the same gene.
b) specify different proteins.
c) may have an influence on the phenotype.
d) represent differences in the genotype.
e) All of the above.

_____49. Breeding two genetically distinct organisms is called
a) promiscuity b) randomization c) cross breeding d) cross pollination e) asexual reproduction

_____50. A convenient graphical method for determining all of the possible combinations of gamete alleles in a cross is called a(n)
a) dichotomous key b) intercalation c) pedigree chart d) Punnett square e) phenogram

_____1. The traits Mendel studied in garden peas showed
a) complete dominance b) incomplete dominance c) epistasis d) pleiotropy e) polygenic inheritance

_____2. A classical example of incomplete dominance is
a) ABO blood groups in humans
b) height of garden peas
c) pink flowers in heterozygous snapdragons
d) coat color in rabbits
e) albinism in humans and animals

_____3. A classical example of codominance is
a) ABO blood groups in humans
b) height of garden peas
c) pink flowers in heterozygous snapdragons
d) coat color in rabbits
e) albinism in humans and animals

_____4. What causes the effects of Marfan's syndrome?
a) the lack of pigment production
b) an extra 21 chromosome
c) the presence of two different codominant alleles
d) inability to produce normal connective tissue
e) the environment interacting with the genotype

_____5. A classical example of epistasis is
a) ABO blood groups in humans
b) height of garden peas
c) pink flowers in heterozygous snapdragons
d) coat color in rabbits
e) albinism in humans and animals

_____6. Marfan's disease in humans, with it numerous effects, is an example of
a) dominance modification
b) incomplete dominance
c) epistasis
d) pleiotropy
e) polygenic inheritance

_____7. A classical example of multiple alleles is
a) coat color spotting in cattle
b) height of garden peas
c) pink flowers in heterozygous snapdragons
d) coat color in rabbits
e) albinism in humans and animals

_____8.A gene interaction in which pairs of recessive genes at one locus prevents expression of a dominant allele at another locus is called
a) complete dominance b) incomplete dominance c) epistasis d) pleiotropy e) polygenic inheritance

_____9. What causes Down syndrome?
a) the lack of pigment production
b) an extra 21 chromosome
c) the presence of two different codominant alleles
d) inability to produce normal connective tissue
e) the environment interacting with the genotype

_____10. What causes the effects of albinism?
a) the lack of pigment production
b) the environment
c) inability to produce normal connective tissue
d) the presence of two different codominant alleles
e) an extra 21 chromosome

_____11. What is the hereditary cause of type AB blood?
a) an extra 21 chromosome
b) the presence of two different codominant alleles
c) inability to produce normal connective tissue
d) the lack of pigment production
e) the environment

_____12. Skin color in humans, caused by several genes at several loci, is an example of
a) multiple alleles at one locus
b) incomplete dominance
c) epistasis
d) pleiotropy
e) polygenic inheritance

_____13. The inheritance of skin color in humans is an example of which of the following?
a) Pleiotropy b) Codominance c) Epistasis d) Polygenic inheritance e) Gene linkage

_____14. X-linkage was discovered for the first time in
a) ants b) mice c) chickens d) fruit flies e) humans

_____15. Which statement is Not true about X-linked characteristics?
a) More males than females are affected.
b) Females can be carriers of the gene without showing it.
c) The characteristic often skips a generation, from a women's father to her son.
d) Males can have two copies of the allele for the trait, but females can have only one.

_____16. Which of the terms would be equivalent to 3n chromosomes?
a) tetraploidy b) monosomy c) diploidy d) triploidy e) etrasomy

_____17. Which refers to turning a chromosome segment around 180 degrees and rejoining it to the original chromosome?
a) inversion b) translocation c) deletion d) duplication e) monosomy

_____18. Which refers to the loss of a complete chromosome?
a) inversion b) translocation c) deletion d) duplication e) monosomy

_____19. Which refers to the movement of a piece of one chromosome to another nonhomologous chromosome?
a) inversion b) translocation c) deletion d) duplication e) monosomy

_____20. Which refers to the loss of a portion of a chromosome?
a) inversion b) translocation c) deletion d) duplication e) monosomy

_____21. Which refers to the addition of an extra segment of a chromosome?
a) inversion b) translocation c) deletion d) duplication e) monosomy

_____22. In incomplete dominance, there is no
a) genetic crossing b) homozygous phenotypes c) dominant or recessive alleles d) intermediate traits

_____23. Type AB blood is an example of
a) codominance b) incomplete dominance c) blending of alleles d) monogenic traits

_____24. Humans can have blood phenotypes of A, AB, B, or O. The four blood types result from
a) codominance b) incomplete dominance c) multiple alleles d) a polygenic trait

_____25. A human with the sex genotype XX is
a) a male b) a dwarf c) a female d) carrying an extra chromosome

_____26. People with Down syndrome have
a) 45 chromosomes b) 46 chromosomes c) 47 chromosomes d) no X chromosome

_____27. Trisomy is a mutation that results in a cell having an extra
a) allele b) codon c) chromosome d) gene

_____28. The X and Y chromosomes are called the
a) extra chromosomes b) phenotypes c) sex chromosomes d) autosomes e) female chromosomes

_____29. A change in a gene due to damage or being copied incorrectly is called
a) evolution b) meiosis c) segregation d) a mutation

_____30. Which of the following describes hemophilia?
a) multiple-allele trait b) dominant trait c) sex-link trait d) codominant trait

_____31. Human skin color is determined by three different genes working together to produce a wide range of possible
skin tones. This is an example of
a) Blending inheritance b) Codominance c) Polygenic trait d) Polyploidy e) Multiple alleles

_____32. A human male has _____ chromosomes with ____ sex chromosomes.
a) 46, XY b) 48, XY c) 46, XX d) 48, XX e) 46, YY

_____1. Which of the following is Not true about a karyotype?
a) Homologous chromosomes are paired.
b) Sex chromosomes are identified separately from autosomes.
c) Chromosome pairs are numbered from smallest to largest.
d) Chromosome pairs are assorted by both size and shape.
e) Banding patterns are used in paring.

_____2. Karyotyping can be used to diagnose which of the following genetic disorders?
a) Down syndrome b) phenylketonuria c) neurofibromatosis d) cystic fibrosis e) hemophilia

_____3. Chorionic villus sampling uses what tissue to analyze the fetal cells and provide a karyotype?
a) fetal blood tissue
b) cells floating in the amniotic fluid
c) a small biopsy from the embryo itself but it readily heals
d) membrane tissue from the embryo side of the placenta
e) membrane tissue from the mother's side of the placenta

_____4. When homologous chromosomes fail to separate during meiosis, this is termed
a) cross over b) RFLP c) linked genes d) disjunction e) nondisjunction

_____5. Generally, it is not possible to determine whether nondisjunction failed to occur in oogenesis or spermatogenesis.
However, it is possible to assert that _____ results in nondisjunction in _____.
a) XXY; oogenesis
b) XXY; spermatogenesis
c) XXX; oogenesis
d) XYY; spermatogenesis
e) XO; oogenesis

_____6. In some cases of Down syndrome, there is a translocation between chromosomes
a) 21 and 13 b) 21 and 14 c) 21 and 18 d) 21 and 22 e) X and Y

_____7. Which statement is Not true about Down syndrome?
a) It is caused by a third copy of chromosome 21.
b) Greatly increased incidence occurs with fathers over age 35.
c) It is associated with chromosomal nondisjunction in meiosis.
d) Characteristics include mental retardation and extra eyelid folds.
e) Affected individuals have a considerably shortened life expectancy.

_____8. Considering that males are produced by Klinefelter (XXY) syndrome, XYY and normal XY chromosome combinations,
and females are produce by Turner (XO) syndrome, triple-X (XXX) and normal XX combinations, it is obvious that
a) maleness is caused by the presence of only one X chromosome.
b) femaleness is caused by the presence of two or more X chromosome.
c) maleness is caused by the minimal presence of one Y chromosome.
d) maleness occurs in the absence of two or more X chromosomes.
e) sex determination is a delicate balance between X and Y chromosomes.

_____9. Which genetic trait is Not associated with the chromosome involved in Down syndrome?
a) cataracts b) mental retardation c) Alzheimer disease d) Cystic fibrosis e) increase incidence of leukemia

_____10. Which one of these is caused by repeats of base triplets rather than a whole chromosome?
a) Down syndrome b) Edward syndrome c) Klinefelter syndrome d) fragile-X syndrome e) Turner syndrome

_____11. Which sex chromosome abnormally is correctly associated with the proper genotype?
a) Turner syndrome – XXY b) triple-X – XO c) Klinefelter syndrome - XXY

_____12. A male with underdeveloped testes, breast development, subnormal intelligence, and an abnormal karyotype is likely to have
a) Turner syndrome b) Huntington disease c) Klinefelter syndrome d) Down syndrome e) Edward syndrome

_____13. In a pedigree chart, which is correct?
a) Circles = males; Squares = females
b) A line between a circle and a square represents a mating.
c) A carrier with a normal phenotype is represented by a black circle or square.
d) Offspring are represented by triangles.

_____14. Which of the following diseases is not inherited as an autosomal recessive?
a) neurofibromatosis b) Tay-Sachs disease c) phenylketonuria d) albinism e) cystic fibrosis

_____15. Huntington disease is
a) caused by a mutated recessive gene on chromosome 21.
b) usually fatal before the individual reaches reproductive age.
c) usually inherited from a gene from the father.
d) due to a lack of an enzyme needed to metabolize phenylalanine, and damage can therefore be controlled by a diet lacking this amino acid.
e) All of the above are correct.

_____16. The most common lethal genetic disorder among Caucasians is
a) neurofibromatosis b) Tay-Sachs disease c) phenylketonuria d) albinism e) cystic fibrosis

_____17. Which of the following diseases is most prevalent in the Jewish community?
a) neurofibromatosis b) Tay-Sachs disease c) phenylketonuria d) albinism e) cystic fibrosis

_____18. Phenylketonuria is
a) caused by mutated gene on chromosome 12.
b) easily detested by high levels of phenylalanine in urine or blood.
c) the most common inherited disease of the nervous system.
d) due to a lack of an enzyme needed to metabolize phenylalanine, and damage can therefore be controlled by a diet lacking this amino acid.
e) All of the above are correct.

_____19. Which type of inheritance results in continuous variation - often a bell shaped curve - because genes at many loci are involved?
a) polygenic b) autosomal dominant c) autosomal recessive d) X-linked e) sex-influenced

_____20. Which is associated with the inability to produce factor VIII in the blood?
a) male pattern baldness
b) sickle-cell disease
c) color blindness
d) hemophilia
e) Duchenne muscular dystrophy

_____21. If the parents are AO and BO genotypes for the ABO blood group, their children could include which of the following genotypes?
a) AO and BO only
b) AO, BO and AB only
c) AA, BB and AB only
d) AO, BO, and OO only
e) AO, BO, AB and OO only

_____22. Which disease results in deformed red blood cells, poor circulation, and anemia?
a) male pattern baldness
b) sickle-cell disease
c) color blindness
d) hemophilia
e) Duchenne muscular dystrophy

_____23. Which provides protection against malaria in the heterozygote?
a) Duchenne muscular dystrophy
b) hemophilia
c) sickle-cell disease
d) male pattern baldness
e) color blindness

_____24. If a women is a carrier for the color-blindness recessive allele and her husband is normal, what are their chances that a son will be color blind?
a) None since the father is normal.
b) 50 percent since the mother is the only carrier.
c) 100 percent because the mother has the gene.
d) 25 percent because the mother is a hybrid.
e) None since he will also be just a carrier.

_____25. Autosomal dominant inheritance is shown by all but which of the following?
a) Marfan syndrome b) color blindness c) brachydactyly d) hypercholesterolemia e) achondroplastic dwarfism

_____26. Queen Victoria and some of her descendants carried an X-linked gene for
a) Duchenne muscular dystrophy
b) sickle-cell disease
c) hemophilia
d) male pattern baldness
e) color blindness

_____27. A genetic disorder (not counting disjunction) is more likely to be common in the population if it
does not manifest itself until after reproductive age has passed.
a) is recessive.
b) bestows some benefit in a heterozygous state.
c) is not sex-linked if recessive.
d) all of the above would increase the survival of a deleterious gene.

_____28. Which is inherited as a dominant in males but only expresses in the presence of testosterone?
a) pattern baldness
b) Duchenne muscular dystrophy
c) sickle-cell disease
d) color blindness
e) hemophilia

_____29. Which of the following is an X-linked condition?
a) Hemophilia b) Tay-Sachs disease c) Huntington's disease d) Cystic fibrosis e) Sickle-cell anemia

_____30. A child is diagnosed with Tat-Sachs disease. Which of the following organelles is most likely affected?
a) lysosome b) ribosome c) Golgi apparatus d) rough endoplasmic reticulum e) Peroxisomes

_____31. In a pedigree, you notice that individuals who have a single parent with the condition have the condition themselves
50 percent of the time. Of the following, which condition has an inheritance pattern that best fits the description?
a) Tay-Sachs disease b) Huntington's disease c) Cystic fibrosis d) Sickle-cell anemia e) Phenylketonuria

_____32. From which parent(s) did a male with red-green color blindness inherit the defective allele?
a) Only the mother.
b) Only the father.
c) The mother or father, but not both.
d) Both the mother and the father.
e) It is impossible to determine with certainly using only the given information.

_____33. A human genetic defect that is caused by nondisjunction of the sex chromosomes is
a) Sickle-cell anemia b) Hemophilia c) Down syndrome d) Turner syndrome e) red-green color blindness

_____34. Duchenne's muscular dystrophy is inherited as a sex-linked recessive allele. From whom does a male with
this disease inherit the defective allele?
a) Only his mother.
b) Only his father.
c) The mother or father, but not both.
d) Both the mother and the father.
e) It is impossible to determine with certainly using only the given information.

_____35. Turner syndrome occurs in humans whose cells are missing the Y chromosome. all of the following are
True about Turner syndrome Except
a) A Turner syndrome zygote results when a sperm missing a Y chromosome fertilizes a normal egg.
b) A Turner syndrome zygote results when a normal sperm bearing an X chromosome fertilizes an egg missing an X chromosome.
c) During meiosis, nondisjunction occurs to produce one of the gametes used to form the Turner syndrome zygote.
d) The zygote has 45 chromosomes.
e) Barr bodies form in the nuclei of Turner syndrome individuals.

_____36. Color blindness in humans is
a) caused by a recessive allele
b) in equal proportion in both sexes
c) caused in females by a heterozygous genotype
d) caused in males by a homozygous genotype

_____37. If a characteristic is sex-linked it
a) occurs most common in males c) occurs only in females
b) can never occur in females d) is always fatal

_____38. Both sickle cell anemia and hemophilia
a) are caused by genes coding for defective protein c) are seen in homozygous dominant individuals
b) provide resistance to malaria infection d) are extremely common throughout the world

_____39. A diagram in which several generations of a family and the occurrence of certain genetic characteristics are shown is called a
a) Punnett square b) monohybrid cross c) pedigree d) family karyotype

_____40. Which of the following describes hemophilia?
a) multiple allele trait b) dominant trait c) sex-linked trait d) codominant trait

_____41. Charts that show how a trait is inherited are called
a) Punnett squares b) pedigrees c) karyotype charts d) genetic charts

_____42. A photograph that show chromosomes in homologous pairs is called a what?
a) karyotype b) pedigree c) phenotype d) genotype

_____43. In a pedigree, a shaded circle or square indicates a person who has
a) an allele for a trait only. c) the trait as well as its allele.
b) a male allele. d) a female allele.

_____44. Which of the following is shown in a karyotype?
a) a pedigree chart b) DNA models c) chromosomal abnormalities d) ultrasound

_____45. Turner syndrome is a disorder in which a person has one X chromosome and
a) one Y chromosome c) two Y chromosomes
b) no other sex chromosome d) one other sex chromosome

_____46. An example of a disorder caused by a defective chromosome structure is
a) Klinefelter syndrome b) Cri-du-chat syndrome c) nondisjunction d) Turner syndrome

_____47. People with Down syndrome are often prone to
a) heart defects b) sterility c) loss of hair d) a cry that sounds like a cat

_____48. Males with Klinefelter syndrome may have
a) excessively hairy bodies c) no Y chromosome
b) large heads d) breast development

_____49. A genetic disorder that causes secretion of mucus from some organs is
a) cystic fibrosis b) Tay-Sachs disease c) Huntington's disease d) sickle-cell anemia

_____50. People with Huntington's disease develop deterioration of the
a) circulatory system b) reproductive system c) heart d) nervous system

_____51. The allele for Tay-Sachs disease is found most often among
a) African Americans b) Caucasians c) Jewish people d) Hispanic people

_____52. Sickle cell disease results in production of abnormal
a) nerve cells b) hemoglobin c) color vision d) muscle tissue

_____53. Two examples of sex-linked disorders are.
a) hemophilia and color blindness c) color blindness and sickle-cell anemia
b) hemophilia and cystic fibrosis d) hemophilia and malaria

_____54. Phenylketonuria is a disorder that causes inability to use
a) hemoglobin b) oxygen c) a single amino acid d) all proteins

_____55. Since the allele for colorblindness is located on the X chromosome, colorblindness
a) cannot be inherited c) occurs only in adults
b) is sex-linked d) only occurs in females

_____56. If nondisjunction occurs,
a) there will be too many gametes produced
b) no gametes will be produced
c) a gamete will receive too many or too few homologues of a chromosome
d) mitosis cannot take place

_____1. Which is Not a major function of the genetic material?
a) store information c) catalyze chemical reactions
b) replicate itself d) undergo mutations

_____2. DNA was discarded as a possible candidate for the genetic material because
a) with only four types of nucleotides, it was a very simple, repetitive molecule that could not account for 20 different amino acids.
b) is had been shown that proteins were more important in transferring genetic information than nucleic acids.
c) proteins and carbohydrates were of more interest.
d) it was thought that RNA was more likely to be the genetic material.

_____3. The process of transformation in bacteria involves
a) transfer of genes for making a mucous capsule.
b) infection with a virus called bacteriophage.
c) production of a cancer cell.
d) the matting of two different kinds of live bacteria.

_____4. DNA was first proven to be the transforming factor on bacterial cells by
a) Meischer b) Watson and Crick c) Griffin d) McClintock e) Avery

_____5. Hershey and Chase experimented with radioactively labeled phosphorus and sulfur to determine that DNA and not
protein is the genetic material. Which of the following was essential to this confirming experiment?
a) Sulfur is present in amino acids in the protein coat of bacteria.
b) Phosphorus is present in high amounts in DNA.
c) Sulfur is not present in DNA.
d) Phosphorus is not present in amino acids in the protein coat of bacteria.
e) All of the above were critical to demonstrating DNA is involved in genetic material.

_____6. DNA was proven to be the transforming substance when only the _____ enzymes could inhibit transformation.
a) proteinase b) RNase c) DNase d) lipase

_____7. One of Chargaff's rules state
a) A + T = G + C b) A + G = T + C c) A = G, T = C d) A = C, T = G

_____8. The amount of adenine is always equal to the amount of ____ in DNA.
a) cytosine b) uracil c) guanine d) thymine e) ATP

_____9. The x-ray diffraction photography of Rosalind Franklin and Maurice was critical evidence of DNA
a) indicating that DNA has a double helix structure.
b) showing equal number of purines and pyrimidines.
c) showing the bases of DNA were held together by hydrogen bonds.
d) revealing the structure of the deoxyribose sugar.
e) of the location of each adenine, guanine, cytosine, and thymine.

_____10. In the Watson and Crick model of DNA, the "steps" of the ladder are composed of
a) sugars
b) a purine and a pyrimidine
c) two purines
d) two pyrimidines
e) a sugar and a phosphate molecule

_____11. Which of the following statements about DNA replication is Not correct?
a) Unwinding of the DNA molecule occurs as hydrogen bonds break.
b) Replication occurs as each base is paired with another exactly like it.
c) The process is known as semiconservative replication because one old strand is conserved in the new molecule.
d) The enzyme that catalyzes DNA replication is DNA polymerase.
e) Complementary base pairs are held together with hydrogen bonds.

_____12. Because one original strand of the double stranded helix is found in each daughter cell,
the replication process is called
a) proofreading b) semiconservative c) redundant d) freeing DNA e) mutation positive

_____13. Which does Not describe a function of the DNA polymerase molecule?
a) recognize the free nucleotide that pairs with the base on the template strand of DNA
b) read the strand of template DNA and recognize the base there
c) proofread to ensure that the proper base has been incorporated
d) make the proper nucleotide to match with the base read on the template strand
e) cut out an improperly paired nucleotide and replace it with the proper one

_____14. Which statement is Not true about DNA replication?
a) It proceeds in a 5' to 3' direction only.
b) One strand of new DNA is replicated faster than the other strand at the replication fork.
c) DNA can only replicate at one point on a chromosome at one time.
d) It occurs more rapidly in bacteria than in eukaryotes.
e) Replication can only begin at a special origin of replication.

_____15. Which statement is Not correct about the repetitive DNA sequence?
a) They are found in both prokaryotic and eukaryotic cells.
b) Highly repetitive DNA is repeated 100,000 to 1 million times per cell.
c) Repetitive DNA separates regions that direct the synthesis of proteins.
d) The number of repeats of highly repetitive DNA in an individual is used in DNA fingerprinting.
e) Moderately repetitive DNA is seen in genes that code for ribosomal RNA.

_____16. Which statement is Not true about DNA replication in prokaryotes?
a) Replication begins at a single origin of replication.
b) Replication is bidirectional from the origin(s).
c) Replication occurs at about 1 million base pairs per minute.
d) Since bacterial cells replicate so rapidly, a second round of replication may begin before the first has completed.
e) There are numerous different bacterial chromosomes, with replication occurring in each at the same time.

_____17. Which statement is Not true about DNA replication in eukaryotes?
a) Replication of the entire genome takes about ten minutes.
b) A replication fork occurs at each growing point of the replicating chromosome(s).
c) Eukaryotes have numerous different chromosomes, with replication occurring in each at the same time.
d) Replication occurs at the rate of about 500 - 5000 base pairs per minute.
e) Multiple sites of replication are present on each chromosome.

_____18. The two strands of a DNA molecule are held together by
a) ionic bonds b) covalent bonds c) peptide bonds d) hydrogen bonds

_____19. According to the base pairing rules, guanine binds with
a) cytosine b) adenine c) thymine d) guanine

_____20. During DNA replication, the enzyme DNA polymerase
a) separates the two nucleotide chains of a DNA molecule.
b) constructs new nucleotide chains that are complementary to the chains in the original DNA molecule.
c) breaks down the original DNA molecule into individual nucleotides.
d) joins two DNA molecules into a single molecule.

_____21. If the sequence of nucleotides in one chain of a DNA molecule is T-C-A-A-G-C, a new
nucleotide chain will be produced during replication with the complementary sequence
a) T-C-A-A-G-C b) A-G-T-T-C-G c) C-T-G-G-A-T d) G-A-C-C-T-A

_____22. Complementary base pairing links
a) amino acids b) nitrogen containing bases c) phosphate groups d) proteins

_____23. Damage to DNA is usually repaired by
a) purines b) nucleotides c) enzymes d) replication forks

_____24. During replication, the two strands of DNA separate at a point called a(n)
a) helicase b) purines c) replication fork d) phosphate group

_____25. Each nucleotide in a DNA molecule is constructed of
a) a sulfur group, a five carbon sugar molecule, and a nitrogen base.
b) a phosphate group, a six carbon sugar, and a nitrogen base.
c) a phosphate group, a five carbon sugar, and a oxygen base.
d) a phosphate group, a five carbon sugar, and a nitrogen base.

_____26. In DNA replication,
a) each new single helix is composed of 50 percent protein and 50 percent DNA protein.
b) each new triple helix is composed of one old DNA strand and two new DNA strands.
c) each new double helix is composed of one old protein strand and one new protein strand.
d) each new double helix is composed of one old DNA strand and one new DNA strand.

_____27. Which of the following is a pyrimidine base?
a) adenine b) guanine c) thymine d) colchicines e) None of the above.

_____28. Which of the following is Not one of the four bases that makes up DNA?
a) adenine b) uracil c) guanine d) cytosine e) thymine

_____29. The diameter of the DNA ladder is always
a) 3.0 nm b) 2.0 nm c) 1.5 nm d) 2.5 nm e) 3.4 nm

_____30. Each complete turn of the DNA helix is how long?
a) 3.0 nm b) 2.0 nm c) 3.4 nm d) 2.1 nm d) 5.0 nm

_____31. Which of the following is a purine base?
a) cytosine b) thymine c) adenine d) malomine e) All of the above.

_____32. The structure of DNA is most like a
a) figure eight b) double triangle c) double helix d) double ellipse e) None of the above.

_____33. Which of the following is Not a proper base pairing for DNA?
a) A – C b) T – G c) C – A d) G – T e) All of the above.

_____34. Griffin did an experiment in which live R bacteria was changed by dead S bacteria.
Such a change is an example of
a) translocation b) transduction c) fertilization d) transformation

_____35. Chargaff's rule state that in DNA, the amount of adenine equals
a) the amount of cytosine c) the amount guanine
b) the amount of thymine d) the amount of guanine and thymine

_____36. Rosalind Franklin helped reveal the structure of DNA by using
a) X-ray crystallography b) cytosine analysis c) centrifuge analysis d) bacteriaphages

_____37. The correct structure of DNA is a(n)
a) double helix b) diamond c) octagon d) single strand

_____38. The term replication refers to DNA's ability to
a) respond to X-ray photography c) attack bacteriaphages
b) make copies of itself d) twist into a helix

_____39. Which is Not a characteristic of DNA?
a) cytosine
b) long strands of nucleotides
c) a "backbone" of sugar and phosphate
d) uracil
e) double helix

_____40. The direction of replication of DNA is
a) 5' to 3' b) 3' to 5' c) 5' to 5' d) 3' to 3' e) variable

_____41. If a change is made when DNA copies itself, a ________ results.
a) clone b) death c) mutation d) base pair

_____42. A section of DNA with bases A-T-T-C-G-C will line up with bases
a) T-A-A-G-G-C c) A-T-T-C-G-C
b) T-A-A-G-C-G d) T-A-A-G-C-C

_____1. The concept of an "inborn error of metabolism" was the first recognition of the relationship between
gene activity and metabolic disease, made by
a) Beadle and Tatum with parasitic molds.
b) Pauling and Itano with sickle cell anemia.
c) Sir Archibold Garrod from general family inheritance patterns.
d) Watson and Crick, as a natural outcome of their model of DNA.
e) Gregor Mendel, who extrapolated his pea plant data to human disease.

_____2. Studies by Beadle and Tatum that produced the "one gene-one enzyme hypothesis"
were conducted using the
a) bread mold Neurospora crassa
b) bacterium Streptococcus pneumoniae
c) bacterium E. coli
d) mouse
e) human

_____3. The idea that a single gene coded a polypeptide rather than an enzyme was evident from the
a) use of X-rays to make nutritional mutants in bread mold.
b) transformation of bacteria from rough and nonvirulent to smooth and virulent.
c) presence of a mutation in one chain of hemoglobin but not in the other.
d) discovery that mutated genes changed enzymes in a biochemical pathway.
e) finding that some genes in eukaryotes are split by introns.

_____4. Today, it is most appropriate to state that a gene controls
a) one enzyme
b) one protein
c) one polypeptide chain
d) one amino acid
e) one starch, amino acid or lipid molecule

_____5. Which of the following classes of RNA molecules carries the genetic information as it is needed
for the construction of a protein?
a) ribosomal RNA b) transfer RNA c) messenger RNA d) primary mRNA transcript

_____6. Which of the following classes of RNA molecules carries the amino acids that are added to the
growing polypeptide chain?
a) ribosomal RNA b) transfer RNA c) messenger RNA d) primary mRNA transcript

_____7. Which of the following classes of RNA molecules is found in almost no prokaryotes?
a) ribosomal RNA b) transfer RNA c) messenger RNA d) primary mRNA transcript

_____8. Which of the following classes of RNA molecules is linked with proteins in forming the large and
small subunits of a cytoplasmic structure?
a) ribosomal RNA b) transfer RNA c) messenger RNA d) primary mRNA transcript

_____9. Prior to protein synthesis, the DNA
a) attracts tRNAs with appropriate amino acids.
b) must first undergo replication.
c) contains anticodons that must become codons.
d) serves as a template for the production of mRNA.
e) adheres to ribosomes for protein synthesis.

_____10. Which of the following classes of RNA molecules is never found in the cytosol?
a) ribosomal RNA b) transfer RNA c) messenger RNA d) primary mRNA transcript

_____11. The first codon to be deciphered was _______, which codes for ______.
a) AAA, praline b) GGG, alanine c) UUU, phenylalanine d) TTT, arginine e) CCC, glycine

_____12. Transcription of a part of a DNA molecule with a nucleotide sequence of A-A-A-C-A-A-C-T-T
results in a mRNA molecule with the complementary sequence of
a) G-G-G-A-G-A-A-C-C
b) U-U-U-G-U-U-G-A-A
c) T-T-T-G-A-A-G-C-C
d) C-C-C-A-C-C-T-C-C
e) None of the above.

_____13. If one strand of DNA has the base sequence A-A-G-C-A-A, the complementary strand
has which of the following sequences?
a) U-U-C-G-U-U b) T-T-C-G-T-T c) A-A-G-C-A-A d) U-T-C-G-T-U e) T-T-C-G-T-G

_____14. Which is the process that synthesizes mRNA, tRNA, or rRNA?
a) translation b) transcription c) transposition d) transformation

_____15. Which of the following nucleotide bases is found only in RNA, not in DNA?
a) guanine b) adenine c) thymine d) uracil e) cytosine

_____16. Which of the following nucleotide bases is found only in DNA, not in RNA?
a) guanine b) adenine c) thymine d) uracil e) cytosine

_____17. An intervening sequence in a eukaryotic gene that is not an active part of the gene is called a(n)
a) exon b) intron c) replicon

_____18. A ribozyme is
a) a section of the DNA that is expressed in the mRNA.
b) a self splicing intron that acts like an enzyme.
c) a complex made up of many ribosomes replicating the same strand of mRNA.
d) one of the small ribosomal subunits.
e) the enzyme that attaches amino acids to tRNA.

_____19. Which is the process by which a protein is constructed?
a) translation b) transcription c) transposition d) transformation

_____20. In order to produce many copies of a protein fast, the cell uses
a) DNA replication
b) intron self splicing
c) codon-anticodon reciprocal duplication
d) many RNA polymerase molecules to produce mRNA transcripts at the same time

_____21. Which is most directly responsible for the sequence of amino acids in a protein?
a) the sequence of the anticodons
b) the number of codons in mRNA
c) the enzyme that attaches the amino acid to tRNA
d) the proteins associated with rRNA
e) the sequence of codons in mRNA

_____22. Which is Not true about the genetic code?
a) It is exactly the same in all organisms.
b) It is composed of triplet code of three bases per codon.
c) It produces 64 different possibilities of base sequences.
d) It was cracked through the use of a cell free system of enzymes.

_____23. For translation to take place, which of the following would Not be required to be present?
a) DNA b) mRNA c) RNA-amino acid complex d) rRNA e) ribosome

_____24. Which of the following processes does Not take place during translation?
a) Growth of a polypeptide chain.
b) Attachment of a ribosome to mRNA.
c) Binding of two tRNA molecules per ribosome.
d) Liberation of polypeptide from ribosome.
e) Production of mRNA.

_____25. The correct sequence of events in the production of a polypeptide is
a) initiation, termination, elongation
b) elongation, termination, initiation
c) termination, elongation, initiation
d) elongation, initiation, termination
e) initiation, elongation, termination

_____26. Which of the following is Not a form of ribonucleic acid, or RNA?
a) messenger RNA b) ribosomal RNA c) transfer RNA d) translation RNA

_____27. During transcription, the genetic information is rewritten as a molecule of
a) messenger RNA b) ribosomal RNA c) transfer RNA d) translation RNA

_____28. In a cell, the equipment for translation is located in the
a) cytosol b) nucleus c) plasma membrane d) centrioles

_____29. The number of nucleotides required to specify one amino acid is called a
a) genome b) codon c) radon d) intron e) exon

_____30. Each codon is how many nucleotides long?
a) 3 b) 4 c) 5 d) 6 e) 9

_____31. Each codon specifies a(n)
a) genetic sequence b) amino acid c) nucleotide d) intron e) exon

_____32. Codon that signal the end of a polypeptide chain are called
a) silent codons b) secret codons c) stop codons d) stop introns

_____33. How many amino acids are there?
a) 8 b) 9 c) 10 d) 20 e) 64

_____34. The process by which DNA transfers its information to RNA is called
a) transmutation b) transmittal c) translation d) transcription

_____35. During transcription, the information in the DNA is rewritten, or transcribed, in the form of
a) RNA b) proteins c) codons d) polypeptides

_____36. The RNA copy of the information from DNA is composed of
a) tRNA b) mRNA c) pRNA d) rRNA

_____37. The conversion of the message carried by the RNA into polypeptides is called
a) transmutation b) transmittal c) translation d) transcription

_____38. The starting signal for mRNA synthesis is a special sequence of DNA called a
a) promoter b) director c) polymerase d) primer

_____39. In eukaryotes transcription factors lead the RNA polymerase to the
a) adjacent polypeptide b) promoter c) codon d) primer

_____40. Both eukaryotes and prokaryotic RNA polymerase stop transcription at a special sequence called
a) transcriptors b) terminal codons c) terminators d) translation ends

_____41. Interruptions in pre-mRNA, or intervening sequences, are called
a) positrons b) interrupters c) introns d) mistakes

_____42. In RNA, thymine is replaced by
a) adenine b) guanine c) cytosine d) uracil

_____1. Which gene in an operon is incorrectly matched with its function?
a) promoter - where RNA polymerase first binds to DNA
b) regulator - binds to the repressor protein
c) structural - make mRNA by transcription
d) operator - if unbound, allows RNA polymerase to bind to DNA

_____2. Which statement is Not correct about the lac operon?
a) It regulates the production of a series of five enzymes.
b) It is normally turned off if glucose is present.
c) Lactose binds to the repressor protein and inactivates it.
d) It is an inducible system.
e) The structural genes make products that allow lactose metabolism.

_____3. Which statement is Not correct about the trp operon?
a) The structural genes make products that act in a metabolic pathway to produce tryptophan.
b) It is normally turned off if tryptophan is present.
c) Tryptophan acts as the corepressor.
d) The regulator gene product is inactive by itself.
e) Tryptophan binds to the repressor protein and inactivates it.

_____4. Which statement is Not true about genetic control in prokaryotes?
a) RNA polymerase must bind to a promoter on the DNA to begin RNA synthesis.
b) Most gene expression is regulated at the level of translation.
c) An active repressor protein keeps RNA polymerase from binding to DNA.
d) Structural genes produce enzymes that act in a metabolic pathway.

_____5. Stopping mRNA from being continuously translated into protein is an important mechanism when
enough protein product is available. How is this accomplished?
a) Transcribe antisense RNA from ordinarily inactive DNA; this will bind with sense mRNA and prevent the
ribosome from further translating it.
b) Regulator genes produce repressor proteins that physically bind to mRNA and stop its activity in ribosomes.
c) mRNA contains stop units encoded in its sequence so only a limited number of passes can be made
through ribosomes.
d) The protein products of mRNA translation are feedback repressors that limit translation.
e) Other genes turn on to produce enzymes that digest mRNA.

_____6. The universal regulatory mechanism in eukaryotes for controlling gene expression includes
a) control of the genes transcribed and the rate they are transcribed.
b) control of the processing of mRNA after it is transcribed from DNA but before it leaves the nucleus,
and control of the rate it leaves the nucleus.
c) control the mRNA in the cytoplasm after it leaves the nucleus, including changes to mRNA
before translation begins.
d) control of polypeptides after they have been synthesized but before they are functional.
e) All of the above are used; there is no single universal mechanism.

_____7. The first level of primary control in eukaryotic gene activity is ________ control.
a) feedback b) translational c) transcriptional d) posttranscriptional e) posttranslational

_____8. Which level of primary control in eukaryotic gene activity involves the life span of the mRNA molecule
and the ability of the mRNA to bind to ribosomes?
a) feedback b) translational c) transcriptional d) posttranscriptional e) posttranslational

_____9. Which level of primary control in eukaryotic gene activity involves processing earl RNA transcripts to
mRNA and control of the rate at which mRNA leaves the nucleus?
a) feedback b) translational c) transcriptional d) posttranscriptional e) posttranslational

_____10. Which level of primary control in eukaryotic gene activity involves changes in the polypeptide
chain before it becomes functional?
a) feedback b) translational c) transcriptional d) posttranscriptional e) posttranslational

_____11. A form of active chromatin might also be referred to as
a) a Barr body b) heterochromatin c) a chromosome d) euchromatin

_____12. An enhancer site is
a) part of an operon c) found only in prokaryotes
b) located at a distance from genes it effects d) an attachment site for RNA polymerase

_____13. A form of gene regulation that occurs while RNA is still in the nucleus is
a) differential intron removal and splicing
b) feedback control
c) binding of the repressor protein to DNA
d) enzymatic cleavage of a polypeptide
e) rate of binding to ribosomes

_____14. "Jumping genes" that have the ability to move within and between chromosomes are called
a) introns b) exons c) transposons d) retroviruses e) oncogenes

_____15. A deletion of one base pair that alters the sequence of codons, as the loss of "A" in
C-C-G-T-A-G-C to form C-C-G-T-G-C is called a(n)
a) transposon b) point mutation c) carcinogen d) oncogene e) frameshift mutation

_____16. All of these are considered carcinogens Except
a) cigarette smoke
b) ultraviolet light
c) cabbage and related vegetables
d) certain viruses
e) radon

_____17. An oncogene is
a) a viral gene with no relation to the host cell's genes.
b) a mutated form of a proto-oncogene.
c) a bacterial gene that causes cancer in the host.
d) always seen in human cancer cells.
e) a gene that turns off cellular reproduction.

_____18. You are more likely to develop some forms of cancer.
a) are exposed to higher doses of radiation including X rays.
b) are exposed to carcinogens.
c) have a high incidence of cancer in your family.
d) have an immunodeficiency.
e) All of the above are correct.

_____19. Carcinogens promote mutations in genes that control the cell cycle at the most critically regulated phases at
a) G2 to S and G1 to mitosis
b) S to G1 and G2 to mitosis
c) S to G2 and G1 to mitosis
d) G1 to S and G2 to mitosis
e) all stages

_____20. A gene is expressed when it is
a) present in the genome of an individual
b) prevented from interacting with RNA polymerase
c) transcribed into mRNA and that mRNA is translated into protein
d) duplicated during the replication of DNA

_____21. In the lac operon of E. coli, lactose functions as
a) a promoter b) an operator c) a repressor protein d) an inducer

_____22. In eukaryotic cells, transcription occurs
a) on parts of the DNA that are uncoiled c) only on introns
b) only on exons d) on all parts of the DNA

_____23. Unlike gene expression in prokaryotes, gene expression in eukaryotes
a) cannot be regulated before transcription has occurred
b) can be regulated after transcription has occurred
c) does not involve promoters
d) involves the transcription of groups of genes called operons

_____24. Enhancers
a) code for proteins called inducers c) must be located close to the genes they activate
b) are found only in prokaryotic genomes d) facilitate transcription by binding to transcription factors

_____25. The major distinguishing characteristic of cancer is
a) uncontrolled cell division c) rapid cell division
b) metastasis d) tumor formation

_____26. A gene whose normal function is to prevent uncontrolled cell division is
a) an oncogene b) a cancer gene c) a homeotic gene d) a tumor suppressor gene

_____27. The spread of cancer cells beyond their original site is called
a) gene expression b) morphogenesis c) metastasis d) cell differentiation

_____28. Pre mRNA is a form of RNA that contains
a) euchromatin b) prokaryotic transcription factors c) introns and exons d) only exons

_____29. Operons have been identified in
a) prokaryotes only b) eukaryotes only c) archaebacteria only d) both prokaryotes and eukaryotes

_____30. Active transcription in eukaryotes occur within
a) an operon b) an operator c) euchromatin d) an enhancer

_____31. The activation of a gene that results in the formation of a protein is called
a) translation b) gene expression c) enhancement d) gene repression

_____32. An operon consists of
a) a group of operators c) a group of structural genes
b) an operator, a promoter, and structural gene d) lactose, polymerase, and operators

_____33. Normal genes that control a cell's growth and differentiation are called
a) tumor suppressor genes b) oncogenes c) proto-oncogenes d) growth factors

_____34. The lac operon
a) is found in eukaryotic cells
b) codes for the sequence of amino acids in lactose
c) regulates the translation of mRNA
d) regulates transcription by turning on or off the production of a repressor protein
e) regulates DNA replication by turning on or off the production of inducer protein

_____35. Which of the following carries the code that determines the sequence of monomers in a protein?
a) rRNA b) tRNA c) mRNA d) The large ribosome subunit e) DNA polymerase

_____36. Which of the following is a frameshift mutation?
a) CAT HAS HIS TO - CAT HAS HIT
b) CAT HAS HIS TO - CAT HSH IST
c) CAT HAS HIS TO - CAT HIS HAT
d) CAT HAS HIS TO - CAT WAS HIT
e) CAT HAS HIS TO - CCT HAS HIT

_____37. A mutation that causes premature completion of protein synthesis due to a substitution error is known as a(n)
a) Frameshift mutations
b) Missenese mutations
c) Nonsense (Point) mutations
d) Thymine dimmer
e) Duplication error

_____38. The correct order of molecules involved in protein synthesis is
a) messenger RNA, transfer RNA, DNA, polypeptide
b) DNA, messenger RNA, polypeptide, transfer RNA
c) polypeptide, DNA, messenger RNA, transfer RNA
d) DNA, messenger RNA, transfer RNA, polypeptide
e) transfer RNA, polypeptide, messenger RNA, DNA

_____39. A tumor suppressor gene can prevent replication of damaged DNA by
a) degrading the damage DNA
b) blocking the cell cycle at the G1 checkpoint
c) activating a newly transcribed DNA molecule
d) initiating lysis of the cell containing the damage DNA
e) methylating the defective nucleotides

_____40. Some portions of chromatin remain condensed permanently, even during the uncoiling after division.
This chromatin is
a) euchromatin b) heterochromatin c) chromatid d) prochromatin e) histone

_____41. When eukaryotic gene is transcribed, the primary RNA transcript contains
a) sequence complementary to the entire gene, but prior to protein synthesis, the introns are cut out.
b) sequence complementary to the entire gene, but prior to protein synthesis, the exons are cut out.
c) only the exons that will be used in translation.
d) only the introns that will be used in translation.
e) defective sequences that will be excised by DNA polymerase prior to translation.

_____42. Which of the following can influence the amount of gene expression in prokaryotes?
a) Introns b) Enhancers c) Poly-A-tail d) 5 prime guanine cap e) None of the above.

_____43. After mRNA has been transcribed,
a) its introns are cut out c) its exons are joined together
b) it leaves the nucleus by way of pores d) All of the above.

_____44. In prokaryotic cells, group of genes that code for functionally related proteins is a(n)
a) exon b) intron c) operon d) riboson

_____45. The function of an operator is to
a) regulate access to RNA polymerase to structural genes c) turn on and off the molecules of tRNA
b) control the process of transcription within the nucleus d) generate amino acids for protein synthesis

_____46. A repressor protein
a) prevents DNA synthesis c) blocks movement of RNA polymerase
b) attaches to ribosomes during translation d) destroys amino acids before protein synthesis occurs

_____47. Inducer molecules allow the transcription to proceed by
a) destroying repressor molecules c) unwinding the cell's DNA molecules
b) activating the ribosomes d) changing the shape of repressor molecules

_____48. What type of gene codes for a repressor?
a) regulator b) promoter c) operon d) enhancer

_____49. An inducer molecule functions by
a) causing DNA replication c) binding the rRNA subunits of a ribosome
b) removing a repressor molecule from an operator d) digesting lactose molecules in bacteria cells

_____50. The balance between a stimulatory signals and inhibitory signals determines whether
a) a cell is normal or malignant.
b) a cell conducts normal metabolism or undergoes apoptosis.
c) proto-oncogenes are active.
d) tumor-suppressor genes are active.
e) Both C and D.

_____1. What is the function of a vector in genetic engineering?
a) cut DNA into many fragments
b) carry DNA into a new cell
c) link together newly joined fragments of DNA
d) make millions of copies of a specific segment of DNA
e) separate fragments of DNA by their length and electrical charges

_____2. Which of the following molecules forms lengths of DNA with "sticky ends"?
a) DNA ligase b) DNA polymerase c) RNA polymerase d) reverse transcriptase e) restriction enzyme

_____3. What is the function of a restriction enzyme in recombinant technology?
a) cut DNA into many fragments
b) carry DNA into a new cell
c) link together newly joined fragments of DNA
d) make millions of copies of a specific segment of DNA
e) separate fragments of DNA by their length and electrical charges

_____4. What is the function of DNA ligase in recombinant technology?
a) make millions of copies of a specific segment of DNA
b) carry DNA into a new cell
c) separate fragments of DNA by their length and electrical charges
d) cut DNA into many fragments
e) link together newly joined fragments of DNA

_____5. What is complementary DNA (cDNA)?
a) the strand of DNA opposite the strand used to make mRNA
b) a sequence of DNA as it is found in the genome
c) any sequence of cloned DNA
d) DNA made from a mature mRNA template
e) DNA made through the polymerase chain reaction

_____6. What is Not useful as a possible DNA probe?
a) a protein that binds to DNA specifically
b) a sequence of mRNA that binds to a particular site on DNA
c) DNA produced by DNA synthesizer to have a particular base sequence
d) cDNA that is complementary to a particular region of the genome DNA
e) a sequence of single-stranded, radioactive DNA that binds to the gene of interest

_____7. What is the function of the polymerase chain reaction in genetic engineering?
a) separate fragments of DNA by their length and electrical charges
b) cut DNA into many fragments
c) make millions of copies of a specific segment of DNA
d) link together newly joined fragments of DNA
d) carry DNA into a new cell

_____8. All of the following statements are true about restrictive enzymes Except
a) They are made by bacteria and viruses
b) The first one was isolated in 1970.
c) Hundred of different ones have been isolated and purified.
d) The produce single-stranded complementary ends that can join together two different DNA strands.
e) Each enzyme cuts DNA at a different specific base sequence.

_____9. For "DNA fingerprinting" to associate a blood sample with the criminal, or estimate the evolutionary similarity
of an extinct quagga as closer to a zebra than a horse, what is minimally required?
a) one sample of DNA, PCR amplification, restriction enzymes, and gel electrophoresis
b) one sample of DNA, restriction enzymes, a DNA synthesizer, and gel electrophoresis
c) two samples of DNA, PCR amplification, restriction enzymes, and gel electrophoresis
d) two samples of DNA, PCR amplification, a DNA synthesizer, and gel electrophoresis
e) two samples of DNA, PCR amplification, restriction enzymes, and a DNA synthesizer

_____10. To carry out a polymerase chain reaction (PCR), you must have the catalytic DNA polymerase and
a) a blueprint or gene map of the sequence you wish to copy.
b) a number of "primers" from either side of the target DNA in order to get the polymerase replication process going.
c) two of the four nucleotides since the other half will naturally fall in place.
d) a DNA synthesizer machine.
e) a DNA probe.

_____11. Which best describes a transgenic organism?
a) one that acts as the donor for DNA to be moved into another organism
b) one produced by cloning a mutant cell
c) one that contains a foreign gene and is free living in the environment
d) one produced by the polymerase chain reaction
e) any genetically modified organism resulting from laboratory research

_____12. Which is Not one of the major categories of biotechnology products?
a) hormones and similar proteins c) DNA probes
b) toxins for use in pest control d) vaccines

_____13. Plants are expected to be genetically engineered to have
a) a requirement for more fertilizer.
b) an increase water requirement.
c) the ability to produce all the essential amino acids.
d) increase susceptibility to herbicides.
e) All of the above.

_____14. Which of these methods of transferring DNA is useful in bacteria and plants, but Not in animals?
a) virus infection
b) bacteriophage infection
c) plasmid transfer
d) microinjection of DNA
e) laser irradiation of cells in a fluid containing DNA.

_____15. A human product that is being made in genetically engineered microorganisms includes
a) human growth hormone.
b) insulin.
c) tissue plasminogen activator.
d) clotting factor VIII.
e) All of the above.

_____16. Which statement is True about the Human Genome Project?
a) It will immediately reveal the causes of all human diseases.
b) It will allow drugs to be used with universal effectiveness.
c) Linkage data will be more rapidly collected through the use of DNA markers and RFLPs.
d) It is pure research and therefore will only be done through government research funding.
e) It will probably take another 20 years to complete.

_____17. What is the function of gel electrophoresis in genetic engineering?
a) cut DNA into fragments
b) carry DNA into a new cell
c) link together newly joined fragments of DNA
d) make millions of copies of a specific segment of DNA
e) separate fragments of DNA by their length and electrical charges

_____18. Gene therapy in humans involves all Except
a) insertion of the gene for bovine growth hormone.
b) alternation of lymphocytes to contain an enzyme for the maturation of T and B cells.
c) alternation of bone marrow stem cells to allow synthesis of the product in all kinds of blood cells.
d) use of reverse transcriptase to move recombinant RNA into the chromosome as recombinant DNA.
e) treatment of endothelial cells lining blood vessels with a special delivery system.

_____19. When bone marrow stem cells are removed from the blood and infected with a retrovirus that carries
a normal gene, this is an example of
a) PCR b) chemotherapy c) viral disinfection d) in vivo gene therapy e) ex vivo gene therapy

_____20. Which of the following techniques is Not used in preparing DNA fingerprints?
a) gene therapy b) RFLP analysis c) gel electrophoresis d) polymerase chain reaction

_____21. In gel electrophoresis, DNA fragments migrate toward on end of the gel because they are
a) pulled toward that end by gravity.
b) attracted to complementary DNA fragments at that end of the gel.
c) attracted to the positively charged end of the gel.
d) repelled by hydrophobic molecules at the other end of the gel.

_____22. The accuracy of DNA fingerprinting can be increased by comparing
a) segments of DNA that tend to vary the least from person to person.
b) noncoding segments where the DNA repeats over and over.
c) DNA from identical twins.
d) repeat patterns at only one or two sites in the genome.

_____23. In addition to DNA polymerase, and primers, the polymerase chain reaction also requires
a) a large amount of DNA. c) restriction enzymes.
b) a supply of the four DNA nucleotides. d) complementary sequences of RNA.

_____24. One of the goals of the Human Genome Project is to
a) increase the number of genes in he human genome.
b) map the location of only the most important genes on each chromosome.
c) clone the entire human genome in bacteria.
d) determine the nucleotide sequence of the entire human genome.

_____25. An advantage of genetically engineered vaccines over traditional vaccines is that they
a) are effective against unidentified pathogens. c) may be safer.
b) are more specific to the disease they protect against. d) are easier to produce.

_____26. An exact copy of a gene is called a
a) plasmid b) donor gene c) cloning vector d) gene clone

_____27. Gene therapy currently
a) can be used to treat certain diseases, such as cystic fibrosis.
b) can be used to cure certain diseases, such as cystic fibrosis.
c) provides cures for diseases that can be passed on to the chromosomes of humans.
d) All of the above.

_____28. Which of the following is Not a current application of genetic engineering?
a) the insertion of pest-resistance genes into crop plants.
b) the production of human insulin by bacterial cells.
c) the construction of genomic libraries and the identification of specific genes.
d) the insertion of normal genes into human fetuses that carry defective genes.

_____29. Restrictive enzymes
a) cleave DNA between G and A in a GAATTC nucleotide sequence.
b) cleave DNA at specific sites within specific sequences of DNA.
c) recognize specific genes and cleave them out of a DNA molecule.
d) All of the above.

_____30. Recombinant DNA is
a) plasmid DNA which a piece of foreign DNA has been added.
b) any combination of DNA from a bacterium and a eukaryote.
c) any combination of DNA from two or more different sources.
d) bacterial DNA to which a cloning vector has been added.

_____31. A pattern of bands made up of a specific DNA fragments is a
a) restriction enzyme. b) cloning vector c) homeotic gene d) DNA fingerprint

_____32. The process that separates DNA fragments according to their size and charge is
a) gel electrophoresis b) RFLP analysis c) polymerase chain reaction d) the isolation of a gene

_____33. DNA technology is being used to produce medicines by
a) growing genetically engineered bacteria and collecting human DNA that they produce.
b) growing genetically engineered bacteria and collecting human proteins that they produce.
c) Neither A or B
d) Both A and B

_____34. To cut DNA molecules into pieces at specific sequences of nucleotides, genetic engineers use
a) cloning vectors b) insulin c) bacteria d) restriction enzymes

_____35. A ring of DNA found in bacterium in addition to the bacterium's main chromosome is called a
a) sticky end b) plasmid c) donor gene d) gene clone

_____36. To obtain bacteria that produce insulin, genetic engineers
a) remove repressor proteins that inhibit the expression of the bacterial insulin gene.
b) insert a vector containing the human gene for insulin into bacteria.
c) search for bacteria that can grow in a medium that lacks insulin.
d) grow normal bacteria in a nutrient medium that contains a large amount of sugar.