Chapter 8: Genome Structure, Chromatin, and the Nucleosome Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

How long is the human genome?

A

2 meters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How do prokaryotes and eukaryotes differ in regards to genomes?

A

Prokaryote genomes are circular and usually have one copy of chromosome. Eukaryote genomes have 2 to 100 chromosomes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How does the genome size correlate to the species complexity?

A

A larger complex organism can call genomes into action in more complicated events then a smaller, less complex organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How does the genome density correlate to the species complexity?

A

More complex organisms have decreased gene density due to intergenic sequences

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are genomes?

A

Genomes are wound around nucleosomes and condensed into in chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

During mitosis, chromosomes are found with two identical strands called ____________

A

Sister strands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How are overlapping genes arranged in eukaryotes?

A

Genomes are typically antiparallel in eukaryotes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define sex chromosomes

A

Carry sex-determining genes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

True or False:

Humans are 99% identical to other mammals

A

False

Humans are 92% identical to other mammals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Explain the chromosome 2 Fusion

A

The Chromosome 2 fusion is a fusion in humans, but separate in other primates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Explain the 44 Chromosome Man

A

Chromosome 14 and 15 are fused.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How genetically similar are humans to all neanderthals?

A

99.84% generally identical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How genetically similar are humans to all chimps?

A

98.77% generally identical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What plays an important in distinguish humans from other animals, and affects expression/regulation?

A

Introns and noncoding intergenic DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Who (males or females) undergo X inactivation?

A

Females

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How did the Y chromosome evolve?

A

The Y chromosomes evolved from the X chromosome. Was once identical to X. Evolves fast.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe repetitive intergenic DNA

A

50% of the human genome DNA is repetitive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe PAR

A

It is the pseudoautosomal regions (PAR1 and PAR2) of the Y chromosome, homologous to the X chromosome. Genes in this region are inherited in an autosomal rather than a strictly sex-linked fashion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe SRY

A

It is the male-specific transcription factor for sex determination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Chromatin is made up of ______ and ______

A

DNA, Protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the smallest virus?

A

Hepatitis delta virus (1700 nt)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

True or False:

Eukaryotes have polyploid cells

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

The more complex an organism, the _____ its gene density

A

less

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The larger an organisms genome size, the ________ its complexity

A

greater

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

More complex organisms have decreased gene density due to __________

A

Intergenic sequences

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

True or False:

The mitochondria genome had genes with overlapping exons

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

True or False:

There are 6 million base pairs of DNA per diploid cell

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Define X inactivation

A

One X undergoes inactivation in the cells of females

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

True or False:

Sex ratio is 50% in all animals

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Define intron

A

A segment of DNA or RNA molecule which does not code for proteins and interrupts the sequence of genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What causes gene duplication?

A
  • DNA polymerase slippage
  • Unequal crossing over
  • Trisomy
  • Transposon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Transposons

A

Cut themselves out and move to different location

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Retrotransposons

A

Transcribed by RNA polymerase into RNA. Then encodes reverse transcriptase and copies themselves somewhere else in the genome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

________ are derived from ancient viral infections

A

Endogenous Retroviruses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the Alu element?

A

The Alu element is a transposon descended from signal recognition particle which targets proteins to ER

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Explain the horizontal gene transfer

A

Genes can be shared horizontally between species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is within the coding RNA?

A

Messenger RNA with exons

38
Q

Explain alternative splicing

A

Produces 100,00 transcripts from the 20,000 genes and generate isoforms with different functions. 95% may be an error

39
Q

_________ act as scaffolding, guides, effectors/enhancers the regulate genes, and act as a signal for viral tranSfection.

A

Long noncoding RNA

40
Q

______ forms a hairpin secondary structure. Regulates post transcriptional gene expression

A

MicroRNA

41
Q

_____ is a response to foreign RNA and is often 100% complementary

A

siRNA

42
Q

miRNA can inhibit _________

A

Translation

43
Q

MicroRNA are _____-specific

A

Tissue

44
Q

_____ is a type of coding RNA

A

mRNA

45
Q

Define centromere of chromosomes

A

Only 1 per chromosome. The point of attachment for kinetochore proteins which link chromosomes to microtubles.

46
Q

Define telomeres of chromosomes

A

Single-stranded ends of chromosomes, repeats of TTAGGG

47
Q

When do Sister chromatids exists?

A

S phase to M phase

48
Q

_______ protects the ends of chromosomes. may anchor chromosomes to the edge of the cell during division

A

Telomeres

49
Q

The _________ is chromosome duplication and chromosome segregation

A

Cell Cycle

50
Q

Phase at which the cell cycle is at rest (quiescent)

A

G0

51
Q

Phase of the cell cycle for growth and prearation

A

G1

52
Q

Explain the S (synthesis) phase

A

DNA synthesis, each chromosome is duplicated to produce two sets of sister chromatids

53
Q

Phase of the cell cycle that allows preparation for division

A

G2

54
Q

Explain the M (mitosis) phase

A

Sister chromatid centromeres are bund by kinetochore proteins, which attach to the mitotic spindles

55
Q

At what phase does DNA replication occurs?

A

S phase

56
Q

At what phase does DNA segregation occurs?

A

M phase

57
Q

Cell cycle checkpoints

A

Cell with DNA damage will arrest in G1 before synthesis

58
Q

Movement in the cell is regulated by ______ and ________

A

cyclins and cyclin-dependent kinases (CDKs)

59
Q

True or False:
DNA replication and histone synthesis which results in two identical sister chromatids per chromosome.

At what phase does this occur?

A

True

S phase

60
Q

Sister chromatin are bound by _______

A

Cohesin

61
Q

When is cohesin added to DNA?

A

S phase

62
Q

During prophase, ______ is added to condense chromosomes

A

Codensin

63
Q

What is the function of Aurora B Kinase?

A

Checks and regulates microtubule attachment, senses tension via phosphorylations

64
Q

Explain the metaphase plate alignment

A

Kinesin and dynein controls alignment at the metaphase plate.

65
Q

This enzyme cuts cohesin

A

Separase

66
Q

True or False:

Crossing over is essential to mitosis

A

False

…. essential to meiosis

67
Q

What is the tension that holds chromosomes together during meiosis 1?

A

Recombination

68
Q

What is the tension that holds chromosomes together during meiosis 2?

A

Cohesion

69
Q

What is the tension that holds chromosomes together during mitosis?

A

Cohesion

70
Q

What are nucleosomes?

A

The building blocks of chromosomes

71
Q

What is the function of topoisomerase?

A

Relaxes DNA that is too overwound

72
Q

Describe the solenoid model

A

A superhelix with six nucleosomes per turn

73
Q

Describe the zigzag model

A

The longer link passes through the center of the fiber

74
Q

Define acetylation

A

loosening, activation (HATs and HDACs, which are drug targets)

75
Q

Define methylation

A

silencing, represseon, occasional activation. Can be mono, di, or trimethylated (HMTs and HDMAs)

76
Q

True or False:

Chromosome organization affects transcription

A

True

77
Q

True or False:

To access gene, remove the genome by nucleosome sliding, histone exchanging, or nucleosome eviction

A

True

78
Q

True or False:

Alternating patterns of A-T and G-C benefits the nucleosome

A

True

79
Q

Histone tail can be modified by _____, _____, and _______

A

acetylases, methylases, and ATPases

80
Q

The modification of histone tail affects …

A

chromatin structure, function, and gene expression

81
Q

Which drug targets loosens and activates the DNA?

A

HATs and HDACs

82
Q

Serine, arginine, lysine, and threonine can be modified by …..

A

Phosphorylation, acetylation, methylation, ubiquitination, SUMOylation

83
Q

Which drug targets can silence, repress, and sometimes activates DNA?

A

HMTs and HDMs

84
Q

Loosening of the DNA is called ______

A

Acetylation

85
Q

Tightening of the DNA is called _______

A

Methylation

86
Q

Explain histone code

A

Proteins can read the modifications and modify gene expression

87
Q

Bromodomains recognizes acetylation or methylation?

A

Acetylation

88
Q

Chromodomains recognizes acetylation or methylation?

A

Methylation

89
Q

True or False:

Bromodomains recognizes acetylated lysines

A

True

90
Q

True or False:

Chromodomains recognizes methylated lysines

A

True