Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biochem V > Chromosomal Aberrations > Flashcards

Chromosomal Aberrations Flashcards

(51 cards)

Start Studying
1
Q

What is the percentage of chromosomal aberrations at birth? Pregnancies?

A
  1. 2%

0. 5%

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

What are the two main processes that generate structural chromosomal aberrations?

A

healing of DNA by double stranded breaks

unbalanced recombination

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

How does Cri-du-chat arise?

A

deletion on chromosome 5

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

What is DiGeorge syndrome also known as?

A

velocardiofacial syndrome

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

How does DiGeorge syndrome arise?

A

microdeletion on chromosome 22

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

What is the mode of inheritance for DiGeorge Syndrome?

A

autosomal dominant

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

Where does a translocation insert a chromosome? Insertion?

A

end of another chromosome

insertion = middle

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

What happens in a Robertsonian translocation?

A

long and short arms of a chromosome are exchanged

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

What is the most common chromosomal aberration in humans?

A

Robertsonian translocation

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

Which chromosomes are often involved in a Robertsonian translocation?

A

13q and 14q

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

What is an inversion?

A

chromosome suffers two breaks and is re-inserted in the wrong orientation

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

What is a balanced chromosomal rearrangment?

A

no change in the amount of genetic material

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

What can nondisjunction in meiosis lead to?

A

cells with surplus or missing chromosomes

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

What are the two processes that generate structural chromosomal aberrations?

A

non-homologous end joining and

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

What is more severe, deletions or duplications?

A

deletions

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

How does Cru du Chat arise?

A

deletion on chromosome 5

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

How does diGeorge syndrome arise?

A

microdeletion on chromosome 22

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

What is DiGeorge syndrome also known as?

A

velocardiofacial syndrome

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

What is the most common phenotype of DiGeorge syndrome?

A

congenital heart defect

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

Where does an insertion move a chromosome?

A

into the middle of another chromosome

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

What does a translocation move a chromosome?

Study These Flashcards
A

attaches it to the end

22
Q

How is the Philadelphia Chromosome generated?

Study These Flashcards
A

a translocation between chromosome 9 and 22

23
Q

Regarding the Philadelphia Chromosome, what specific genes are traslocated?

Study These Flashcards
A

ABL tyrosine kinase from 9 to the BCR region on 22

24
Q

What is a Robertsonian translocation?

Study These Flashcards
A

long and short arm of two chromosomes are exchanged

25
What is the most common chromosomal rearrangement?
Robertsonian Translocation of 13q and 14q
26
What is an inversion?
when a chromosome suffers two breaks and the broken-off fragment is re-inserted into the wrong direction
27
What happens when an inverted chromosome pairs with its homolog during meiosis?
an inversion loop is created
28
Regarding a Robertsonian Translocation, what usually happens to the short arm containing chromosome?
it gets lost
29
Regarding the philadelphia chromosome, what gene moves to what chromosome?
ABL from 9 moves to BCR of 22
30
A robertsonian translocation often involves which two chromosomes?
13q and 14q
31
What will an inverted chromosome form in meiosis?
inversion loop
32
Regarding an inversion loop, what can meiosis create?
a dicentric or acentric chromosome
33
When do patients usually become aware of their balanced translocation?
reproduction
34
What cells is most frequently used to perform karyotypes?
lymphocytes
35
What cell cycle phase are chromosomes arrested in during karyotyping?
metaphase
36
Where does methylation of DNA occur?
on cytosine residues in CpG islands
37
What protein is responsible for introducing de novo methylation of DNA?
DNMT 3a and 3b
38
What protein is defective in Rett Syndrome?
methyl cytosine binding protein
39
What characteristic of DNA is lost during Rett Syndrome?
Loss of txn silencing
40
How is Rett Disease transmitted?
X-linked dominant
41
Where does the silencing of histones occur via acetylation?
tail
42
In addition to acetylation, what are three other modifications of histones?
phosphorylation, ubiquitination and methylation
43
What protein binds methylated histones?
HP1
44
What happens to histones after they are deacetylated?
they become methylated
45
What do HP1 proteins bind?
histone methylase
46
What are MBPs?
methylcytosine binding proteins
47
What is the function of imprinting?
to silence chromosomal regions by DNA methylation
48
What signals an end to histone methylation?
a boundary element
49
How does methylation of cytosine proceed?
it is self propogating
50
What role is imparted by imprinting?
mark a chromosome as maternal or paternal in origin
51
When is an inversion loop formed?
during meiosis

Biochem V (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions