Question 1

A chromosome has broken, and a piece of one chromosome is translocated to a non- homologous chromosome. This is an example of what type of chromosomal alteration?

Accepted Answer

A)  Robertsonian translocation 
B)  paracentric inversion 
C)  unbalanced translocation 
D)  dicentric bridge 
E)  inversion loop

Question 2

"Seedless" fruits and vegetables have how many chromosomes and what type of chromosomal distribution?

Accepted Answer

The answer of "Seedless" fruits and vegetables have how many...

Question 3

Histone proteins are the principal agents in chromatin packaging. The nucleosome core particle is a heterooctam protein complex that contains two molecules each of the four histones H2A, H2B, H3, and H4. Describe the proce managing existing nucleosome core particles during replication and the process of adding these and new nucleo core particles to DNA after the replication
fork passes.

Accepted Answer

The answer of Histone proteins are the principal agents in...

Question 4

When nondisjunction occurs early in embryogenesis rather than gametogenesis, what would you expect in the resulting karyotype?

Accepted Answer

A)  uniparental disomy 
B)  monosomy 
C)  mosaicism 
D)  trisomy 
E)  random X- inactivation

Question 5

A region of a chromosome spanning the centromere is broken and reattached in the reverse direction. This is an example of which type of chromosomal defect?

Accepted Answer

A)  dicentric inversion 
B)  dicentric translocation 
C)  pericentric inversion 
D)  paracentric inversion 
E)  pericentric translocation

Question 6

Which of the following correctly lists the levels of compaction in eukaryotes from naked DNA to the most compact?

Accepted Answer

A)  nucleosome, looped chromatin (300- nm fiber), metaphase chromosome, solenoid 
B)  nucleosome, solenoid, looped chromatin (300- nm fiber), metaphase chromosome 
C)  metaphase chromosome, nucleosome, solenoid, looped chromatin (300- nm fiber) 
D)  solenoid, metaphase chromosome, nucleosome, looped chromatin (300- nm fiber) 
E)  solenoid, nucleosome, looped chromatin (300- nm fiber), metaphase chromosome

Question 7

Which of the following is true regarding heterozygous carriers of large chromosome inversions or translocations?

Accepted Answer

A)  They typically have a reduction in the number of viable gametes. 
B)  They commonly exhibit phenotypic abnormalities. 
C)  Translocation heterozygotes will produce viable gametes regardless of the pattern of segregation of the involved chromosomes. 
D)  They should be completely fertile because no genes were deleted. 
E)  Inversion heterozygotes will only produce viable gametes if they have a paracentric inversion, but not a pericentric inversion.

Question 8

The phenomenon of _____________ in allopolyploids consists of more rapid growth, increased fruit and flower production, and improved disease resistance.

Accepted Answer

The answer of The phenomenon of _____________ in allopolyploids consists...

Question 9

There is clear evidence that chromatin state is directly related to the ability of transcriptionally active proteins to initiate gene transcription. Compare and contrast euchromatin to heterochromatin in the context of transcription.

Accepted Answer

The answer of There is clear evidence that chromatin state...

Question 10

Which type of chromosome deletion is caused by two concurrent chromosome breaks (rather than a single break)?

Accepted Answer

A)  acentric deletion 
B)  partial deletion 
C)  terminal deletion 
D)  interstitial deletion 
E)  microdeletion

Question 11

You are attempting to isolate cells for your karyotype, and you find one cell in each of the phases (prophase, metaphase, anaphase, and telophase). Which one is best suited for a karyotype?

Accepted Answer

The answer of You are attempting to isolate cells for...

Question 12

What are the two common patterns of chromosome segregation seen in the tetravalent structures found in translocation heterozygotes?

Accepted Answer

The answer of What are the two common patterns of...

Question 13

Which histone protein is not part of the core nucleosome structure?

Accepted Answer

A)  H1 
B)  H4 
C)  H2B 
D)  H2A 
E)  H3

Question 14

Donkeys have a somatic chromosome number of 62. Hybrids produced by crossing donkeys and zebras are called zonkeys, are sterile, and have many characteristics intermediate between the two parental species. If a zonkey has 52 chromosomes, what is the somatic chromosome number of zebras?

Accepted Answer

A)  62 
B)  42 
C)  52 
D)  31 
E)  21

Question 15

After DNA replication, during reassembly of nucleosomes, the________tetramers are bound by H2A- H2B dimers to form complete nucleosomes.

Accepted Answer

The answer of After DNA replication, during reassembly of nucleosomes,...

Question 16

Cri- du- chat syndrome is a human disorder caused by which type of chromosomal defect?

Accepted Answer

The answer of Cri- du- chat syndrome is a human...

Question 17

A karyotype shows that a child has Klinefelter syndrome (47,XXY). If the child is also color- blind (due to a recessive X- linked allele), despite his parents having normal color vision, in which parent and stage of meiosis did nondisjunction occur?

Accepted Answer

A)  father in meiosis I 
B)  mother in meiosis I or II 
C)  mother in meiosis II 
D)  father in meiosis II 
E)  mother in meiosis I

Question 18

How is aneuploidy different from polyploidy? What are the mechanisms by which aneuploidy and polyploidy are caused, and what are the consequences of these chromosomal alterations in terms of survival and fertility of the offspring?

Accepted Answer

The answer of How is aneuploidy different from polyploidy? What...

Question 19

If nondisjunction occurs in meiosis I of a mother, what proportion of her gametes could have been fertilized by a normal sperm to produce a child with Turner syndrome?

Accepted Answer

A)  1/4 
B)  1/2 
C)  0 
D)  1 
E)  3/4

Question 20

Which proteins would you target if you wanted to disrupt the chromosome superstructure for chromatin condensation that ultimately produces the characteristic shape of the metaphase chromosome?

Accepted Answer

The answer of Which proteins would you target if you...

Exam 10: Chromosome Exam Title Tbd