Genetics Final
Short Answer Questions: The Jack jumper ant has a chromosome content of 2n=2. Draw a diagram of the chromosomes for A) a female somatic cell in metaphase., B) a female primary oocyte in anaphase I, and C) a male somatic cell in anaphase.
2n = 2 means that the Jack jumper ant is typically a diploid with exactly one pair of homologous chromosomes. Sex determination in ants is through haplodiploidy (see Ch. 4 notes). Females are diploid and males are haploid. A) Two duplicated chromosomes (X) lined up in the middle of the cell. B) Two duplicated chromosomes (X) separating from each other. C) Two unduplicated chromosomes (< and >) separating from each other
A chromosome with a centromere at the very end is called___________ . A. telocentric B. acentric C. acrocentric D. metacentric
A
A man with color vision and woman with red-green color-blindness are having a baby. If the baby is a girl, what is the chance that she will be color blind? A. 0% B. 50% C. 100% D. Not enough information
A
A maternal effect can cause offspring to deviate from classic Mendelian inheritance with the offspring's phenotype is determined by __________ and the offspring's genotype is determined by __________. A. the mother's genotype; both parents B. the mother's phenotype; both parents C. both parents; the mother's genotype D. both parents; the mother's phenotype
A
A prophage forms when a ______ bacteriophage enters the _______ cycle. A. temperate; lysogenic B. temperate; lytic C. virulent; lysogenic D. virulent; lytic
A
Crossing over usually occurs during ____________. A. prophase of meiosis !. B. prophase of meiosis II C. anaphase of meiosis I D. metaphase of mitosis
A
Elongation of a new DNA strand occurs ________. A. at the 3' end B. at the 5' end C. at either the 3' or 5' end depending on the template strand D. at either the 3' end or 5' end depending on the DNA polymerase enzyme
A
How do bacterial chromosomes and plasmids differ from each other? A. Generally, essential genes are only located on baterial chromosomes. B. only bacterial chromosomes can replicate C. Plasmids are linear and bacterial chromosomes are circular D. Chromosomes are composed of DNA and plasmids are composed of RNA
A
In which of the following individuals would you typically find hemizygous genes? A. A white-eyed male fly B. A tortoiseshell cat C. A Cameo male peafowl D. A woman who has a color-blind son
A
The Agouti locus in dogs influences the coat color and has 5 common alleles. How many genotypes may there be at this locus? A. 15 B. 25 C. 5 D. 10
A
The ability to curl one's tongue into a U-shape is a genetic trait. Curlers always have at least one curler parent but noncurlers can have one or both parents who are curlers. Using C and c to symbolize the alleles that control this trait, what is the genotype of a noncurler? A. cc B. CC C. Cc D. CC or Cc
A
The formation of the replication holoenzyme _____________. A. allows both lagging and leading strand to by synthesized together B. allows multiple Okazaki fragments to be made at the same time C. only occurs for theta replication D. occurs for both rolling circle and theta replication
A
What does DNA ligase do? A. it joins adjacent strand of newly synthesized DNA together B. It makes the short RNA strands used during DNA synthesis C. it replaces the short RNA strands used during DNA synthesis D. it uses an RNA strand to make a copy made from DNA
A
Which of the following accurately describes bacterial transformation? A. It depends on the amount of DNA in the environment. B. it only occurs between closely related species C. It only occurs under chemical-induced conditions in the lab D. it requires uptake of double-stranded DNA
A
Which of the following describes the way components are arranged along a single strand of DNA? A. Each sugar is attached to two phosphates and a nitrogenous base B. Each phosphate is attached to two sugars and a nitrogenous base C. Each base is attached to two phosphates and a sugar D. Each base is attached to a sugar and a phosphate
A
Which of the following is NOT true about genetic maps A. They are determined by the number of base pairs that separate loci B. They reflect that recombination is more frequent between different loci. C. They accurately predict recombination between locations less than 50 m.u. apart. D. They are associated with specific chromosomes
A
You have discovered mutant form of DNA polymerase in which the proofreading function has been destroyed but the ability to join nucleotides together is unchanged. Which of the following properties do you expect the mutant polymerase to have? A. It will be more likely to generate mismatched base pairs. B. It will polymerize in both the 5'-to3' direction and the 3'-to-5' direction C. It will polymerize more slowly than the normal polymerase. D. It will not be able to replace the RNA primer
A
Polyploidy most often results from _____________. A. the absence of cytokinesis during meiosis or mitosis B. nondisjunction C. increased maternal age D. double stranded breaks along chromosomes
A and B
A Manx cat is a breed of domestic cat that is notable for being tailless. The tailless phenotype is caused by a dominant allele that is homozygous lethal. If two Manx cat are mated, what percentage of the offspring are expected to be tailless? A. 75% B. 66% C. 50% D. 33%
B
A diploid species has a total of 46 chromosomes. How many chromosomes would be found in a monosomy, trisomy, and autotriploid? A. 23; 47; 92 B. 45; 47; 69 C. 45; 69; 47 D. 45; 47; 92
B
A hairpin conformation refers to ______________. A. a rare form of the DNA double helix that has a left-handed helix B. A common motif in RNA that involves base pairing between nearby regions. C. A complex structure formed by distinct regions in large RNA molecules. D. A hybrid structure consisting of RNA and DNA strands
B
A pea plant has a genotype of AaBbccDdEE. How many distinct gametes can this plant produce? A. 4 B. 8 C. 16 D. 25
B
A tall, purple flower plant with genotype Tt Pp is crossed with a tall, white flower plant of genotype Tt pp. 400 progeny are planted. How many of these progeny should you expect to have genotype TTpp? A. 25 B. 50 C. 100 D. 150
B
As DNA is replicated, both continuous and discontinuous replication occur. Discontinuous replication is the result of which specific feature of DNA. A. the supercoiling induced by topoisomerase B. The antiparallel orientation of the strands. C. The covalent bonds between the two strands. D. The presence of the major groove
B
Assume that the diploid number of chromosomes is 18 for a certain species of animal. How many DNA molecules will be found in metaphase II for this species? A. 9 B. 18 C. 36 D. 72
B
DNA replication is considered semiconservative because ____________________________. A. after many rounds of DNA replication, the original DNA double helix is still intact. B. each daughter DNA molecule consists of one strand from the parent DNA molecule and one new strand C. each daughter DNA molecule consists of two new strands copied from the parent DNA molecule D. new DNA strands must be copied from DNA template
B
Diploid cells are cells with _____ chromosomes. A. duplicated B. two sets of C. a single set of D. circular
B
Genes A and B are enzymes that convert a white (W) pigment to red (R) and purple (P) pigments in a species of flowering plant according to the following pathway: a b W>>>>R>>>>P A and B are completely dominant alleles over recessive alleles a and b. What is the expected phenotypic ratio of offspring when a plant with genotype AaBb is self-crossed? A. 12 purple: 4 red: 1 white B. 9 purple: 3 red: 4 white C. 9 purple: 4 red: 3 white D. 9 purple: 6 red: 1 white
B
If a crossover occurs between two homologous chromosomes that are misaligned, which of the following may occur? A. aneuploidy B. a chromosome duplication C. a reciprocal translocation D. a nonreciprocal translocation
B
If the monozygotic twin concordance rate is 42%, which value(s) for the dizygotic twin concordance rate implies that the trait has a significant genetic component? I. 44% II. 16% III. 8% A. All three values B. Both II and III C. Only I D. Only III
B
In a germ-line cell from a female grasshopper (XXXO sex determination system), when do the homologous X chromosomes segregate? A. they do not segregate; gametes contain a copy of X and a copy of Y B. during meiosis I, anaphase C. during meiosis II, anaphase D. during mitosis
B
In humans, the hypothetical gene BLD causes balding. For both males and females, individuals homozygous for the BLD allele are not bald and individuals homozygous for the wild-type BLD+ allele are bald. Interestingly, heterozygous males are bald and heterozygous females are not bald. From this information this trait is likely _______. A. autosomal dominance B. sex-influenced C. sex-limited D. sex-linked
B
In relaxed DNA, 1 turn occurs approximately every ____ bases. A. 8 B. 10 C. 12 D. 14
B
In the cell cycle, what is the "point of no return"? In other words, at what point during the cell cycle does a normally-growing cell become committed to dividing? A. as it finishes S phase B. At the G1/S checkpoint C. at the spindle assembly checkpoint D. as it enters the G0 phase
B
In which of the following organisms is gender/sex determined by the temperature during embryonic development? A. many snakes and birds B. many turtles and alligators C. fruit flies D. puzzlegrass
B
Meiosis I is called the ___________ division, and meiosis II is called the __________ division. A. mitotic; interphase B. reduction; equational C. slow; rapid D. equational; reduction
B
Negative supercoiling of DNA ________________. A. only occurs within bacterial plasmids B. makes it easier to separate the strands during replication C. takes up more space than relaxed DNA D. generates the Z-form of DNA with a left handed helix
B
Round seeds (R) are dominant to wrinkled seeds (r), and yellow seeds (Y) are dominant to green seeds (y). A true-breeding pea plant with round and yellow seeds is crossed to a true-breeding plant with wrinkled and green seeds. The F1 progeny are allowed to self-fertilize. What is the probability that an F2 plant will have the same genotype as its parent? A. 9/16 B. 1/4 C. 3/16 D. 1/16
B
Shugoshin binds to ________ during _________ to prevent ____________ from separating too early. A. centomeres; meiosis; homologous chromosomes B. cohesin; meiosis; sister chromatids C. cohesin; mitosis; sister chromatids D. telomeres; mitosis; sister chromatids
B
Some prokaryotes use short viral sequences to 'remember' old viral infections and fight off new ones. This strategy is known as _______________ A. Restriction modification system B. CRISPR C. viral entry prevention D. prohibitive polysaccharide coating
B
Stepwise condensation of linear DNA happens in five different packing processes. Which of the following four processes has a direct requirement for histone H1? A. formation of "beads-on-a-string" B. formation of 30nm fiber C. looping of 30 nm fiber D. packing of 300nm loops to form interphase chromosomes
B
The number of linkage groups within an organism is determined by _______________________. A. the number of gametes produced during meiosis B. the number of non-homologous chromosomes C. the total amount of DNA in the organism D. the total number of genes in the organism
B
When plated separately, two bacterial strains A and B form hundreds of colonies on complete media, and no colonies on minimal media. However, when the A and B strains are incubated together for 30 minutes, several dozen colonies grow on minimal media. Which of the following conclusions can be made? A. both A and B strains were Hfr strains B. One or more essential genes were transferred from one strain to the other C. One of the strains was infected with a virus D. The A and B strains fused together to form a diploid strain
B
Which of the following best describes the distinction between "Green eyes" and "Eye color" A. Green eyes is a genotype and eye color is a phenotype B. green eyes is a phenotype and eye color is a characteristic C. Green eyes is an allele and eye color is a characteristic D. Green eyes is a characteristic and eye color is a trait
B
Which of the following choices accurately describes bacterial diversity? A. lab have cultivated most bacterial species B. photosynthesis evolved first in bacteria C. bacteria are found in limited number of environments D. bacteria evolved from large eukaryotic cells.
B
Which of the following crosses would produce a 1:1 ratio of phenotypes in the next generation? A. Aa x Aa B. Aa x aa C. aa x aa D. AA x aa
B
Which of the following is typically NOT included in a pedigree? A. matings B. age C. bith order D. sex
B
Which of the following theories of inheritance is currently considered TRUE? A. blending inheritance B. Germ-plasm theory C. inheritance of acquired characteristics D. pangenesis
B
Why is recombination frequency always less than 50% A. because map units on chromosomes can only go up to 50. B. Unlinked genes have recombination frequencies near 50% and segregate independently C. F1 gametes always get 50% of their alleles from each parental gamete. D. The genotype of the F1 gametes will always be 50% parental and 50% recombinant
B
Within a pedigee, the proband refers to ____________________________________. A. mating between related persons B. the person who is first identified with the affected trait C. the oldest living relative identified with the affected trait D. the ancestor is which the mutation first occurred
B
You have just isolated a bacteria from a hot spring in Yellowstone. After purifying its DNA, you determined that 18% of the bases are guanine (G). What percentage of the bases are expected to be adenine (A)? A. 18% B. 32% C. 36% D. 64%
B
Short answer: A single Caenorhabditis elegans hermaphrodite is isolated and allow to generate 240 progeny through selffertilization. She has a roller phenotype because she is heterozygous for a dominant dpy-10 allele (gof). Her progeny consist of 69 wildtype worms (+/+), 129 rollers (gof/+), and 42 dumpy-rollers (gof/gof). A) Construct a Punnett square showing how her progeny is produced, including both genotype and phenotype for each combination. B) Calculate the number of progeny expected for each phenotype. C) Calculate the 2 statistic and degrees of freedom for the data. D) Using the table below, determine the upper limiting p-value for these results and write one sentence interpreting the result.
B) expected progeny is 60 wildtype, 120 rollers, and 60 dumpy-rollers. C) degrees of freedom is 2.
A Robertsonian translocation between chromosome 14 and 21 in humans results in ________________. A. re-green color blindess B. No observable phenotype C. Familial Down syndrome D. Primary Down syndrome
C
A form of a gene that has a slightly different sequence than other forms of the same gene but encodes the same type of an RNA or protein is called a(n) _____________________________. A. homologous chromosome B. locus C. Allele D. heterozygote
C
Approximately how many bases are in the human genome? A. three thousand B. three million C. three billion D. three trillion
C
Considering the pedigree below, which of the following choices is mostly likely to explain the inheritance pattern of the trait. A. Autosomal dominant B. X-linked dominant C. X-linked recessive D. Y-linked
C
Continuous replication ____________________. A. is slower than discontinuous replication B. involves the formation of Okazaki fragments C. proceeds in the same direction as unwinding of the template D. aneuploidy
C
F factor is important which one of the following processes in bacteria? A. Uptake of DNA from the environment B. bacterial transduction C. Formation of a sex pilus D. Replication of bacteriophage
C
Freckles are caused by a dominant allele. A man has freckles but one of his parents does not have freckles. What is the man's genotype? A. homozygous dominant B. homosygous recessive C. heterozygous
C
Gregor Mendel is generally recognized as the father of genetics because he ____________________. A. generated new varieties of pea plants by random crosses of natural varieties. B. discovered that inheritance of specific traits is associated with inheritance of particular chromosomes C. discovered the principles of heredity by crossing different varieties of pea plants and analyzing their traits in subsequent generations. D. All of the above
C
How is a large inversion on a chromosome likely to affect potential offspring? A. no impact because no information is lost B. possible minor affect due to altered gene dosage C. miscarriage or aborted embryo caused by defective gametes D. extra chromosome because of non-disjuction in the gametes
C
In humans, a single Barr body appears in cell nuclei of _______ because _________________________. A. men; his X chromosome is inactive B. men; he inherited two Y chromosomes C. women; one X chromosome is inactive D. women; she inherited three X chromosomes
C
In the snail Cepaea nemoralis, an autosomal allele causing a banded shell (BB ) is recessive to the allele for unbanded shell (BO ). Genes at a different locus determine the background color of the shell; here, yellow (CY ) is recessive to brown (CBw). A banded, yellow snail is crossed with a homozygous brown, unbanded snail. The F1 are then crossed with banded, yellow snails (a testcross). If these two loci are linked and located 20 map units apart, what percent of the progeny is expected to have a banded brown phenotype? A. 40% B. 50% C. 10% D. 20%
C
Prokaryotic chromosomes do NOT have telomeres because they _______________. A. do not go through DNA replication B. do not go through mitosis C. are circular D. are in the cytoplasm
C
Rolling circle elongation _____________. A. occurs in a discontinuous manner B. produces a double-stranded DNA intermediate C. does not require an RNA primer D. is how all bacteria replicate their genome
C
Suppose that a diploid cell contains 8 chromosomes (2n = 8). How many different combinations in the gametes are possible? A. 4 B. 8 C. 16 D. 64
C
Two first cousins get married and have one boy and two girls. One of the girls has a rare heart disorder that is absent in her parents and siblings. Her greatgrandfather (grandfather of both parents) died from a heart attack at 35 years old. What is the likely inheritance pattern for this heart disorder A. autosomal dominant B. cytoplasmic inheritance C. autosomal recessive D. X-linked recessive
C
What is the expected outcome for a human embryo with the XXXY chromosome constitution? A. it would likely develop into a fertile man with completely normal male phenotype B. it will always abort early in development before birth. C. It would likely develop into a sterile male with reduced testes. D. it would be likely to develop into a tall female who may be slightly cognitively impaired.
C
Which of the following choices most accurately describes a sex-linked gene? A. It is expressed only in one sex B. It is involved in sex determination C. It is located on a sex chromosome D. It is only inherited from the mother
C
Which of the following would have prevented Martha Hershey and Alfred Chase from determining the nature of the genetic material in T2 bacteriophage? A. If T2 phage protein and DNA both contained phosphate. B. If T2 phage protein and DNA both entered infected bacterial cells. C. Both A and B.
C
A 50% concordance rate means that _______________________________ A. 50% of all the twins have the trait in at least one member of the twin B. the trait has a significant genetic component C. the trait has a significant environmental component D. If one twin has the trait, the other twin has a 50% chance of having the trait too
D
A replication bubble consists of _____________. A. a replication fork with two lagging strands and another replication fork with two leading strands B. one leading and one lagging strand C. two origins of replication D. two replication forks, each with a lagging and leading strand
D
A testcross would typically be used to __________. A. determine which allele is dominant B. generate a homozygous recessive individual C. determine whether an individual is homozygous or heterozygous for a recessive allele D. determine whether an individual is homozygous or heterozygous for a dominant allele
D
According to Mendel's second law, when the different alleles for one trait separate into gametes, their separation ____________ A. occurs so as to prevent recessive alleles of two different genes from occupying the same gamete B. occurs so that recessive alleles of different genes always occupy the same gamete. C. is dependent on how different alleles for other traits separate D. is independent of how different alleles for other traits separate.
D
All organisms share a common coding system for their genomic information. The common features of heredity imply all of the following EXCEPT that _________________________________. A. genes from one organism will often function in another organism B. the study of one organism's genes often reveals principle that apply to other organisms. C. all life forms on Earth share a common ancestor D. every organism contains a similar amount of DNA
D
An XXY chromosome constitution produces _____ development in humans and _____ development in fruit flies. A. male, intersex B. male, male C. female, male D. male, female
D
Auxotrophic bacterial strains _________________. A. can grow in a liqid broth but not solid agar B. can grow on minimal media C. cannot grow on complete media D. require more supplements to grow than prototrophic strains
D
Dominance refers to ____________________. A. how different genes are expressed B. specific alleles C. specific phenotypes D. the relationship between two alleles
D
During meiosis, a single crossover between two loci results in ________ recombinant and ________ nonrecombinant gametes. A. two; zero B. four; zero C. one; one D. two; two
D
For a diploid organism, the loss of a single chromosome is an example ___________ A. haploidy B. deletion C. trisomy D. aneuploidy
D
How do interspersed repeated DNA sequences differ from tandemly repeated DNA sequences? A. Tandemly repeated DNA has been shown to disrupt genes and cause disease in humans, but interspersed repeated DNA is never associated with human disease. B. Genes are usually founf in tandemly repeated DNA, but not in interspersed repeated DNA. C. The repeats are longer than 1000 base pairs in tandemly repeated DNA, but shorter than 1000 base pairs in interspersed repeated DNA. D. Interspersed repeated DNA comes from transposable elements, but tandemly repeated DNA does not.
D
If two alleles E and F of linked loci are in trans configuration in a dihybrid, which of the following statements are true? A. They are located on non-homologous chromosomes B. They will have a different phenotype than a dihybrid that has them in a cis configuration C. In a testcross, more than 50% of the progeny will have the parental phenotypes. D. The E and F alleles came from different parents
D
In a DNA double helix, ______________________ A. the two DNA strands are identical B. purine pairs with purine C. thymine pairs with cytosine D. the two DNA strands run antiparallel
D
In a flowering plant, the male part of the flower (the stamen) produces haploid microspores. These microspores will then divide by _____ to eventually produce sperm. A. spermatogenesis B. gametogenesis C. meiosis D. mitosis
D
In species of birds, males are the homogametic sex and females the heterogametic sex. Which of the following statements is TRUE in this system of sex determination? A. the gender of the offspring is determined by the male parent B. female offspring have ZZ chromosome constitution C. male offspring have ZW chromosome constitution D. The gender of the offspring is determined by the female parent.
D
James Watson and Francis Crick ______________. A. demonstrated that bacteria can be transformed. B. determined that DNA was the genetic material C. isolated DNA from the cell nucleus D. made a model of the DNA double-helix
D
Non-identical twins have blood type AB and blood type O. From this information, which of the following choices lists ALL of the possible phenotypes for the mother? A. Blood types AB or O B. Blood types A, B, AB or O C. Blood types A, B or O D. Blood types A or B
D
Nucleosomes are composed of _____________. A. four dimers of H3 and H4 B. one copy of H1, H2, H3 and H4 C. two copies of H1, H2, H3 and H4 D. two copies of H2a, H2b, H3 and H4
D
Species in which individuals have only male or only female reproductive structures are called _______. A. hermaphrodites B. homogametic C. monoecious D. dioecious
D
The Baltimore system classifies plant and animal viruses according to which of the following? A. Whether the genome is RNA or DNA B. Whether the genome is single- or doublestranded C. Whether the virus uses reverse transcription D. All of the above
D
The N-terminal tails of histones can be extensively modified by enzymes, and depending on the number, location, and combination of these modifications, these changes may promote the formation of heterochromatin. What is a potential result of heterochromatin formation? A. an increase in gene expression B. displacement of histone H1 C. Early entry into mitosis D. epigenetic inheritance of reduced gene expression
D
The environment often influences each of the following EXCEPT for _____________________. A. epigenetic traits B. continuous traits C. variably expressed traits D. cytoplasmic inheritance
D
What commonsense observation makes the theory of preformationism unlikely? A. Anatomical changes such as loss of a limb are not seen in the offspring B. Evolution requires genetic change in population C. Offspring often look more like their parents than unrelated individuals D.An individual may inherit traits found in both of his or her parents.
D
Which of the following approaches are used to isolate mutant strains that have specific growth requirements. A. colony color assays B. colony growth on minimal agar plates C. liquid cultures D. replica plating
D
Which of the following occurs during prometaphase? A. the chromosomes align in a single plane B. the two sister chromatids separate C. DNA is replicated D. Microtubules attach to the kinetochores
D
Which of the following processes uses cross-overs (recombination) to stably inherit transferred DNA? A. Conjugation B. Transduction C. Transformation D. All of the above
D
If the genome of the bacterium E. coli requires about 20 minutes to replicate itself, how can the genome of the fruit fly Drosophila be replicated in only 3 minutes?
Drosophila DNA contains more origins of replication than E. coli DNA.
Short Answer: Give two examples of how a person's biological sex may be different than their chromosomal sex (assume two sex chromosomes). Describe the specific phenotype (male/female), the chromosomal karyotype, and briefly explain how it occurs.
Several possible answers, including XX individuals that present as male because the SRY gene is translocated to another chromosome, or XY individuals that present as female because the SRY gene is inactive or from androgeninsensitivity genome.
Short answer: Most people think that mutations are harmful and detrimental to species. Give two types of chromosal mutations that are beneficial for evolution. For each one, include the specific type of chromosomal mutation and explain how this type of chromosomal mutation is specifically beneficial in nature.
Several possible answers, including gene duplication which provides an extra copy that can vary during evolution without disrupting normal gene function, autopolyploidy which genome duplication played a role in vertebrate evolution, and inversions which prevent crossing over between genes in the region ensuring that they are inherited together.
What happens to the existing nucleosomes when DNA is replicated in eukaryotes?
They are rapidly reassembled with new histones and distributed to the new strands
