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Genetics Final Fall23

Total questions: 87

Worksheet time: 44mins

Name
Class
Date
1.

In many species, there are two representatives of each chromosome. In such species, the characteristic number of chromosomes is called the _______ number. It is usually symbolized as ______.

a)

diploid; n

b)

polyploid; n

c)

haploid; 2n

d)

diploid; 2n

e)

haploid; n

2.

Genetics is defined as the branch of biology associated with______.

a)
Heredity and variation
b)

replication and recombination

c)

transcription and translation

d)

diploid and haploid

e)

mutation and recession

3.

Early in the twentieth century, Walter Sutton and Theodor Boveri noted that the behavior of chromosomes during meiosis is identical to the behavior of genes during gamete formation. They proposed that genes are carried on chromosomes, which led to the basis _______.

a)

of predicting patterns of inheritance

b)

of the law of independent assortment

c)

for the determination of DNA a genetic material

d)

of the germ-plasm theory

e)

of the chromosome theory of inheritance

4.

The observable feature of an organism is referred to as a ______.

a)

phenotype

b)

genotype

c)

bryophyte

d)

prototype

e)

karyotype

5.

A primary discovery to generate recombinant DNA molecules was the use of ______.

a)

x-ray diffraction

b)

microscopes

c)

bioinformatics

d)

spliceosomes

e)

restriction enzymes

6.

A _____ is an organism produced by biotechnology that involves the transfer of hereditary traits across species

a)

transgenic organism

b)

vector

c)

frankenfood

d)

mutant

e)

clone

7.

The study of structure, function, and evolution of genes and genomes is referred to as ______.

a)

bioinfomatics

b)

cell theory

c)

proteomics

d)

genomics

e)

genetics

8.

______ is a discipline involved in the development of both hardware and software for processing, storing, and retrieving nucleotide and protein data.

a)

cloning

b)

genomics

c)

proteomics

d)

recombinant DNA technology

e)

bioinformatics

9.

Organisms that are well understood from a scientific standpoint and are often used in basic biological research are often called ______.

a)

model organisms

b)

recombinant DNA technology

c)

clones

d)

restriction enzymes

e)

vectors

10.

What is the outcome of synapsis, a significant event in meiosis?

a)

side-by-side alignment of homologous chromosomes

b)

dyad formation

c)

chiasma segregation

d)

monad movement to opposite poles

e)

side-by-side alignment of nonhomologous chromosomes

11.

Which of the following is not a source of genetic variation in meiosis?

a)

law of independent assortment

b)

crossing over

c)

the random lining up of chromosomes on the metaphase plate

d)

polar body formation

e)

tetrad formation

12.

Which of the following is incorrect?

a)

an allele is an alternate form of the same gene

b)

a locus is a gene site on a chromosome

c)

a karyotype is generated from a metaphase spread

d)

homologous chromosomes contain identical genetic information

e)

sex chromosomes are not strictly homologous

13.

Which of the following is true about sex-determining chromosomes?

a)

They are independent during meiosis

b)

They act like homologous chromosomes during meiosis so each gamete will get one sex chromosome

c)

They do not participate in meiosis

d)

They have the same gene configuration and same loci

e)

They are always metacentric

14.

A cross between two individuals with different phenotypes that resulted in approximately 50% of each type of offspring would indicate the cross was ______.

a)

true dominant to a heterozygous dominant

b)

a heterozygous dominant crossed to a homozygous recessive

c)

a heterozygous dominant crossed to a heterozygous recessive

d)

true breeding dominant to recessive

e)

a homozygous recessive crossed to a heterozygous recessive

15.

Which of the following describes the product law?

a)

the probability of two or more independent events occurring simultaneously is equal to the product of their individual probabilities

b)

The product of the sum of the probabilities of two simultaneous events describes the ability of those two events to occur together

c)

The probably of two linked events occurring simultaneously is equal to the probabilities of each individual event

d)

The probability of two or more independent events occurring simultaneously is equal to the sum of their individual probabilities

e)

The probabilities of two events occurring in a specific sequence are the product of their individual probabilities squared

16.

Which genotypic ratio is likely to occur in crosses of two completely dominant, independently segregating gene pairs when both parents are fully heterozygous?

a)

2:4:6:8

b)

1:1:1:1

c)

9:3:3:1

d)

3:2:3:1

e)

3:1

17.

When performing a dihybrid cross for the traits round/wrinkled and yellow/green, which of the following results best demonstrates that the unit factors from each trait was assorting independently?

a)

finding the Punnett square and branched diagram methods yielded the same results

b)

finding only two visible traits in the F1 generation, but four visible traits among the F2 offspring

c)

finding that round is dominant to wrinkled and yellow is dominant is green

d)

the 9:3:3:1 ratio of the F2 generation

e)

finding a 3:1 ratio of round:wrinkled and a 3:1 ratio of yellow:green in the F2 generation

18.

How many kinds of gametes will be expected from an individual with the genotype PpCcTTRr?

a)

16

b)

4

c)

1

d)

2

e)

8

19.

According to Mendel's model, because of the _____ of chromosomes during meiosis, all possible combination of gametes will be formed in equal frequency.

a)

chromosomal theory of inheritance

b)

independent assortment

c)

law of segregation

d)

law of unit factors

e)

product rule

20.

For which of the following questions would you use the sum law?

a)

determining the chance of pulling an ace from a deck of cards

b)

determining the chance of pulling either a club or a heart from a deck of cards

c)

determining the chance of rolling a 5 on a six-sided die

d)

determining the chance of having a baby girl

e)

determining the chance of having a tall plant with purple flowers

21.

In a pedigree analysis a male child with a particular trait has two parents that do not exhibit the that trait. Which of the following represents the most likely scenario?

a)

the trait is inherited as an autosomal recessive and the genotypes of the child a his parent can be determined

b)

the trait is inherited as an autosomal recessive an the genotypes of the child and parents cannot be determined

c)

the trait is inherited as an autosomal dominant and the genotype of the child and his parents can be determined

d)

the trait is inherited as an autosomal recessive and the genotype of the child can be determined but not the genotypes of parents

e)

the traits inherited as an autosomal dominant and the genotypes of the child and parents cannot be determined

22.

Rare autosomal dominant diseases are ______.

a)

typically more severe in homozygous dominant individuals

b)

typically more severe in homozygous recessive individuals than in homozygous dominant individuals

c)

typically similar in severity in homozygous dominant and heterozygous individuals

d)

typically less severe in homozygous dominant individuals than heterozygous individuals

e)

typically not passed on to offspring

23.

To test Mendel's Law of Segregation, the experimenter needs ______.

a)

at least 500 offspring to count

b)

the ability to perform a test cross

c)

a DNA sequencing apparatus

d)

a minimum of two contrasting forms of a gene

e)

access to several generations of data

24.

You have identified a plant in your garden with a new flower color. You want to determine if this phenotype is dominant or recessive. Which cross would tell you this?

a)

crossing the new plant to one you know has the dominant trait

b)

selfing the plant

c)

crossing the plant to one you know has the recessive trait

d)

sequencing the DNA for the trait

e)

crossing the plant to a plant of the same type of any color

25.

Which of the following represents the trihybrid ratio if AaBbCc is selfed?

a)

9:3:3:1

b)

16:9:9:6:6:3:3:1

c)

27:9:9:9:3:3:3:1

d)

18:12:15:9:9:3:3:1

e)

1:1:1:1:1:1:1:1

26.

What information can be obtained from a human pedigree?

a)

Pedigree analysis can help determine how a trait is inherited

b)

Pedigree analysis can help determine where the gene is located on a chromosome

c)

Pedigree analysis can help determine can help determine the type of mutation that caused a specific genetic trait

d)

Pedigree analysis can help identify the chromosome that carries a particular mutation

27.

The following pedigree follows the inheritance of myopia (near-sightedness) in humans. What is the most likely mode of inheritance for this disease? Why?

a)

Recessive, because normal parents can produce affected children

b)

Recessive, because a couple of normal and affected individuals can produce both normal and affected children

c)

Dominant, because a couple of normal and affected individuals can produce both normal and affected children.

d)

Dominant, because normal parents can produce affected children

28.

A mutation in gene that results in a loss of a functional product of that gene best defines what type of mutation?

a)

incomplete dominance

b)

multiple allelism

c)

gain of function

d)

null

e)

codominance

29.

Which of the following is not a characteristic of the ABO gene locus?

a)

dominance/recessiveness

b)

four possible phenotypes

c)

epistasis

d)

multiple alleles

e)

codominance

30.

With which of the following would hemizygosity most likely be associated?

a)

X-linked inheritance

b)

sex-limited inheritance

c)

autosomal dominance

d)

incomplete dominance

e)

codominance

31.

Which of the following statements would be the most likely scenario of offspring of a woman exhibiting an X-linked recessive disorder and a man that does not exhibit the trait?

a)

all offspring will not have the disorder

b)

all daughters will not have the disorder and half the sons will have the disorder

c)

half the daughters and half the sons will have the disorder

d)

all offspring will have the disorder

e)

all daughters will not have the disorder and all sons will have the disorder

32.

A deficiency of the enzyme glucose-6-phosphate dehydrogenase (G6PD) is inherited as an X-linked recessive trait in humans. A phenotypically normal woman (whose father had G6PD) is married to a man with normal G6PD function. What fraction of their sons would be expected to have G6PD deficiency?

a)

1/2

b)

1/4

c)

all

d)

0

e)

not enough information available to determine

33.

Below is a pedigree of a fairly common human hereditary trait in which the boxes represent males and the circles represent females. Shading symbolizes the abnormal phenotype.

Given that one gene pair is involved, what is/are the possible mode(s) of inheritance?

a)

autosomal recessive, X-linked recessive, or X-linked dominant

b)

autosomal recessive

c)

X-linked recessive

d)

autosomal recessive or X-linked recessive

e)

autosomal dominant

34.

Pattern baldness is a sex-influenced trait, with heterozygous males exhibiting the trait. What would be the probability of the daughters exhibiting the trait from a woman with pattern baldness and a male without pattern baldness?

a)

100%

b)

0%

c)

50%

d)

25%

e)

not enough information to determine

35.

A trait exhibited in one sex but not the other is referred to as _____.

a)

sex-limited

b)

sex-linked

c)

genomic imprinting

d)

sex-influenced

36.

90% of children that inherit a mutated retinoblastoma gene develop the disease. This represents an example of ______.

a)

expressivity

b)

a conditional mutation

c)

pleiotropy

d)

genetic imprinting

e)

penetrance

37.

Assume that a cross is made between two organisms that are both heterozygous for a gene that shows incomplete dominance. What phenotypic and genotypic ratios are expected in the offspring

a)

3:1, 1:1

b)

3:1, 1:2:1

c)

1:2:1, 1:2:1

d)

3:1, 3:1

e)

1:1, 1:1

38.

The MN blood group is a codominant trait as a result of which of the following?

a)

presence of M cell surface glycoproteins on some blood cells and N glycoproteins on others

b)

presence of M, M/N intermediate, and N cell surface glycoproteins on blood cells

c)

presence of either M , M/N intermediate, or N cell surface glycoproteins on different blood cells

d)

presence of a M/N intermediate cell surface glycoprotein on blood cells

e)

presence of both M and N cell surface glycoproteins on the same blood cell

39.

What is the probability of having a child with the N blood type, if both parents are MN?

a)

1/4

b)

1.0

c)

3/4

d)

0

e)

1/2

40.

A recessive gene for red-green color blindness is located on the X chromosome in humans. Assume that a woman with normal vision (her father is color-blind) marries a colorblind male. What is the likelihood that this couple's first con will be color-blind?

a)

0%

b)

25%

c)

50%

d)

75%

e)

100%

41.

How do mammals, including humans, solve the "dosage problem" caused by the presence of an X and Y chromosome in one sex and two X chromosomes in the other sex?

a)

They don't, the fact that females have twice as much X chromosome protein products as males is critical for sex determination in mammals

b)

Females produce twice the RNA transcripts as males do, but in females half of them are destroyed before being translated

c)

In males, the X chromosome is up-regulated so that its genes are transcribed and translated twice as much as the X chromosomes in females

d)

In females, one of the X chromosome is condensed and largely inactive so that each sex has one active X chromosome

e)

They don't, but the X chromosome contains genes whose expression is not quantitively sensitive, so the differences are not important

42.

Which of the following is NOT correct for properties of a Barr body?

a)

It is formed as a part of a mechanism for dose compensation

b)

It is a darkly stained region near the nuclear envelope of interphase cells

c)

It is an inactivated X chromosome

d)

It is the same X chromosome in every cell

43.

Which of the following statements about nondisjunction is FALSE?

a)

It only occurs during meiosis I

b)

It may fail to separate maternal from paternal chromosomes

c)

It may fail to separate maternal chromatids from one another or paternal chromatids from one another

d)

It occurs more frequently in human females over age 35

44.

Although the most frequent forms of Down Syndrome are caused by a random error, nondisjunction of chromosome 21, Down syndrome occasionally runs in families. The cause of this form of familial Down Syndrome is _____,

a)

an inversion involving chromosome 21

b)

a chromosomal aberration involving chromosome 1

c)

too many X chromosomes

d)

a translocation between chromosome 21 and 14

e)

a maternal age effect

45.

How many chromosomes would be found in an allopolyploid plant if its parents had diploid numbers of 4 and 6 respectively?

a)

Haploid number of 5

b)

tetraploid number of 10

c)

diploid number of 10

d)

haploid number of 12

46.

How can duplications arise?

a)

uneven crossing over during meiotic prophase

b)

a chromosome break and exchange

c)

spindle failure during chromosome separation

d)

the loss a of telomere

47.

Which of the following statements about the products produced when nondisjunction occurs during meiosis I is true?

a)

Three products of the second meiotic division have too many chromosomes, while one is missing a chromosome for a particular set

b)

Both products of the first meiotic division have too many chromosomes

c)

two products of the second meiotic division have both the maternal and paternal chromosomes of a set and the other two products have none for that set

d)

Both products of the first meiotic division contain dyads representing one chromosome of each homologous pair

48.

What is the specific term that described the loss of one chromosome?

a)

Aneuploidy

b)

Trisomy

c)

monosomy

d)

polyploidy

49.

Cri-du-chat syndrome is due to a _____ in the short arm of chromosome 5.

a)

duplication

b)

segmental deletion

c)

translocation

d)

inversion

50.

Which one of the following statements best describes the evidence that suggests that Down syndrome is more often the result of nondisjunction during oogenesis rather than during spermatogenesis?

a)

The incidence of Down syndrome is due to increasing maternal age is higher than the incidence due to increasing paternal age

b)

Mothers, but not fathers with Down Syndrome can have children with Down Syndrome

c)

The incidence o Down syndrome due to increasing paternal age is higher than the incidence due to increasing maternal

d)

Fathers, but not mothers with Down Syndrome can have children with Down Syndrome

51.

A Robertsonian translocation is considered non-reciprocal because ______.

a)

trisomies of chromosome 21 are viable, whereas monosomies of the same chromosome are not

b)

the smaller of the two reciprocal products of translocated chromosomes is lost

c)

an uneven number of gametes is produced in each meiosis

d)

for every viable gamete formed, there are two inviable gametes formed

52.

Certain varieties of chrysanthemums contain 18, 36, 54, 72, and 90 chromosomes; all are multiples of a basic set of 9 chromosomes. How would you describe these varieties genetically?

a)

aneuploids

b)

autopolyploids

c)

allopolyploids

d)

amphipolyploids

53.

Shown below are two graphs that plot the percentage of fertilized eggs containing males against the atmospheric temperature during early development in (a) snapping turtles and (b) most lizards.

Which of the following TWO statements are consistent with the data presented?

a)

In snapping turtles, sex determination is strongly influenced by temperatures such that males are favored in the 26-34°C range

b)

In snapping turtles, sex determination is strongly influenced by temperatures such that females are favored in the 26-34°C range

c)

Lizards appear to have their sex determined by factors other than temperature in the 20-40°C range

d)

In snapping turtles, sex determination is strongly influenced by temperatures, but there is not range of temperature that favors females

54.

A couple has a son with XYY syndrome, a condition in which an extra copy of the Y chromosome is present. This condition results from nondisjunction. During which meiotic division, and in which parent, could nondisjunction have occurred to produce a child with this condition?

a)

Meiosis I in the mother

b)

Meiosis II in the mother

c)

Meiosis I in the father

d)

Meiosis II in the father

55.

Which of the following elements in responsible for determining male sex in humans?

a)

Pseudoautosomal regions

b)

X-inactivation center

c)

Sex-determining region Y

d)

Male-specific region of the Y

e)

X-inactive specific transcript

56.

Which of the following elements represents a large untranslated transcript involved in inactivation?

a)

Pseudoautosomal regions

b)

X-inactivation center

c)

Sex-determining region Y

d)

Male-specific region of the Y

e)

X-inactive specific transcript

57.

What are pseudoautosomal regions on the sex chromosomes?

a)

They are regions of the X and Y chromosomes that do not recombine during meiosis

b)

They are homozygous regions of autosomal chromosomes

c)

They are homologous regions of the X and Y chromosomes

d)

They are hemizygous regions of the X and Y chromosomes

58.

A human with the karyotype 48, XXXY forms ____ Barr bodies?

a)

0

b)

1

c)

2

d)

3

59.

A male patient with a family history of Fragile-X comes in to have his CGG copy number tested and finds that it is 102. What will be possibilities which he can pass Fragile-X to his kids?

a)

He can pass it on to all his sons.

b)

He can pass it on to some of his sons

c)

He cannot pass it on to any of his sons

d)

He can pass it on to some of his daughters

60.

What is the theoretical limit of observed recombination due to crossing over?

a)

1%

b)

25%

c)

50%

d)

100%

61.

A linkage group ______.

a)

represents some of the genes located on the same chromosome

b)

is a collection of genes that never produce recombinant gametes

c)

is a chromosomal region in which crossing over cannot occur

d)

can occur only on an autosome

62.

If two genes on the same chromosomes exhibit complete linkage, what is the expected F2 phenotypic ratio from a selfed heterozygote with the genotype a+b// ab?

a)

3:1

b)

1:1

c)

9:3:3:1

d)

1:1:1:1

63.

How can the order of three linked genes (A, B, and C) on the same chromosome be determined?

a)

Look for single-crossover phenotypes involving the wild-type and mutant alleles of genes A, B, and C.

b)

Look for parental phenotypes

c)

Gene order cannot be determined by looking at the results of a cross

d)

Look for double-crossover phenotypes involving the wild-type and mutant alleles of genes A, B, and C.

64.

Genes A and B are 10 map units apart and genes B and C are 20 map units apart, with gene B located between genes A and C. What would be the expected amount of double crossovers for a trihybrid test cross?

a)

20%

b)

0.2%

c)

15%

d)

2.0%

e)

30%

65.

What is the unit of distance between genes based on a physical map?

a)

inches

b)

centiMorgans

c)

map units

d)

base pairs

e)

lod scores

66.

What percentage of the human genome codes for the proteins in humans?

a)

15%

b)

23%

c)

about 2%

d)

about 7.5%

e)

70%

67.

The genetic rearrangement that Barbara McClintock discovered was called ______ and the mobile genetic elements she discovered were called _____.

a)

transposition, transposable elements

b)

transposable elements, transposition

c)

transference, transferable elements

d)

mutation, mutable elements

e)

transposition, transposables

68.

Some organisms contain much larger amounts of DNA than are apparently "needed." This is more typical in _____.

a)

viruses than in bacteria

b)

RNA viruses than in DNA viruses

c)

eukaryotes than in prokaryotes

d)

haploids rather than diploids

e)

prokaryotes than in eukaryotes

69.

Which of the following characteristics do bacterial chromosomes share with eukaryotic chromosomes? Both are composed of _____.

a)

single-stranded DNA

b)

single-stranded RNA

c)

double stranded DNA

d)

linear RNA

e)

circular DNA

70.

Which of the following statements regarding mitochondria and chloroplasts is false?

a)

They both typically contain circular, double-stranded DNA

b)

They are inherited through maternal cytoplasm in most organisms

c)

Mitochondria typically contain many more introns than chloroplasts

d)

They contain genetic information remarkably similar to bacteria and viruses.

71.

With which of the following structures does histone H1 directly associate?

a)

nucleosome core particle

b)

H2A/H2B tetramer

c)

the histone octamer

d)

linker DNA

e)

H3/H4 tetramer

72.

Which of the following characteristics is not associated with histones?

a)

Histones octamers are found within nucleosome

b)

Histones are negatively charged

c)

There are five types of histones

d)

Histones play a role in DNA folding

e)

Histones can be chemically modified

73.

Which of the following characteristics is true of heterochromatin?

a)

include regions of DNA that remain largely uncoiled

b)

found in genetically active regions of chromosome

c)

stain more deeply during interphase

d)

replicates early during S phase

e)

not located within centromeres or telomeres

74.

Which type of DNA repair removes via cut-and-patch mechanism a variety of bulky lesions, like pyrimidine dimers and nucleotides to which various chemical groups have been attached?

a)

nucleotide excision repair

b)

base excision repair

c)

mismatch repair

d)

double-strand breakage repair

e)

all of these are correct

75.

What is the proper order of the steps involved in nucleotide excision repair?

1. Release of the damaged DNA segment between the incisions

  1. 2. Sealing of strand by DNA ligase

3. Lesion recognition

  1. 4. separation of the duplex's two strands in the region of the lesion in preparation for its removal

  2. 5. Filling of gap by DNA polymerase

  1. 6. Cutting of the damaged strand on both sides of lesion by endonucleases


a)

3-4-6-5-1-2

b)

3-4-6-1-2-5

c)

3-6-4-1-5-2

d)

3-4-6-1-5-2

e)

3-6-4-2-1-5

76.

Which DNA repair mechanism recognizes a distortion in double helix geometry caused by DNA polymerase's insertion of an incorrect nucleotide during replication, one that escaped the enzyme's proofreading exonuclease?

a)

nucleotide excision repair

b)

base excision repair

c)

mismatch repair

d)

double-strand breakage repair

e)

transcription-coupled pathway

77.

What must the mismatch repair system be able to distinguish in order to tell which nucleotide of a mismatched pair to replace?

1) It must be able to distinguish the newly-made strand from the parental strand.

2.) It must be able to distinguish which chain possesses the newest phosphate groups.

3) It must be able to distinguish which chain contains the ribose sugars

4) It must be able to distinguish which contains the oldest phosphate groups.

a)

1

b)

2

c)

3

d)

4

e)

1 and 2

78.

In mammalian cells, a complex of proteins binds to the broken ends if the DNA duplex and catalyzes a series of reactions that rejoin the broken strands. This is an example of what kid of repair?

a)

nucleotide excision repair

b)

base excision repair

c)

mismatch repair

d)

double-strand breakage repair

e)

nonhomologous end joining

79.

A double-stranded breakage repair pathway that requires the presence of a second chromosome carrying the same sequence of genes as the damaged chromosome is called _____.

a)

nonhomologous end joining repair

b)

homologous recombination

c)

NHEJ

d)

DNA methylation repair

e)

nonhomologous recombination

80.

A mutation that relieves the effects of a previous mutation is called a(n)

a)

spontaneous mutation

b)

induced mutation

c)

dominant negative mutation

d)

loss of function mutation

e)

suppressor mutation

81.

What is the common influence of ultraviolet light on DNA?

a)

tautomeric shifting

b)

adduct formation

c)

depurination

d)

deamination

e)

generation of pyrimidine dimers

82.

How are retrotransposons different from other transposons?

a)

They use an RNA intermediate

b)

They use integrase

c)

They use reverse transcriptase

d)

They use a "copy and past" mechanism

e)

All of these are differences

83.

A class of mutations that results in multiple contiguous amino acid changes in proteins is likely to be which of the following?

a)

recombinant

b)

frameshift

c)

transversion

d)

transition

e)

base analog

84.

Transposons, or jumping genes, are DNA elements that move withing the genome. In which organisms are transposons found?

a)

mommals

b)

ancient bacteria

c)

bacteria

d)

eukaryotes

e)

all organisms

85.

How many tautomeric shift leaf to a mutation?

a)

It allows the insertion of one or more bases in the template strand of DNA

b)

It allows deletion of one or more bases in the template strand of DNA

c)

It allows hydrogen bonding between the nitrogenous bases of the same strand of DNA

d)

It allows hydrogen bonding of normally noncomplementary bases

86.

Most mutations in a diploid organism are recessive. Why?

a)

In most cases the mutations are random and have a deleterious effect on an organsim

b)

In most cases the product from the mutated gene has a lower affinity to the biological targets of the normal genetic product

c)

In most cases the product from the mutated gene is usually degraded by the product from the normal gene

d)

In most cases, the amount of product from one gene of each pair is sufficient for production of a normal phenotype

87.

What experimental evidence suggests that the N-terminal tails of histones participate in the formation of higher-order chromatin structure?

a)

The tails cause histones to denature

b)

The tails when acetylated cause the dissolution of the 30-nm fiber.

c)

Chromatin fibers prepared with H4 histones lacking their tails cannot fold into higher-order fibers

d)

Chromatin fibers prepared with H4 histones processing longer tails cannot fold higher-order fibers

e)

Chromatin fibers lacking tails are shorter