Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Genetics > Chromosomal Mutations > Flashcards

Chromosomal Mutations Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Chromosomal Mutations

A
  1. Variation in the structure
  2. Number of chromosomes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Chromosomic mutations

A
  1. Deletion
  2. Duplication
  3. Inversion
  4. Translocation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Deletion

A

Consists of a deletion of a part of a chromosome

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

2 types of deletions

A
  1. Terminal deletion: consists of a single break in the terminal part of a chromosome
  2. Interstitial deletion: consists of the breakage of the chromosome in the middle of one arm: chromosome without centromere is generated and so is lost during replication
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Cri-di-chat syndrome

A

Deletion of chromosome 5

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

Dangerous consequence of deletion

A

Loss of heterozygosity: copy of genes reduced from 2 to 1 which leads to protein insufficiency

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

Duplication

A

Duplicates a region of the chromosome

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

How is duplication caused?

A

Due to crossing over in which there is unequal pairing of repeated regions due to misalignment

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

Can duplication be advantageous?

A

Yes and it can be fixed and favoured in the genome i.e. alpha and beta globin of hemoglobin

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

A dangerous consequence of duplication

A

Certain regions are overexpressed

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

Inversion

A

Occurs when a part of a chromosome breaks and is rejoined with a rotation of 180 degrees of the sequence

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

Paracentric inversion

A

Does not involve the centromere

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

Pericentric inversion

A

Includes the inverted region and the centromere

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

Where does the issue arise in inversion?

A

When there is a pairing of homologous chromosomes: the pairing occurs in a loop to have the gene’s sequences matching

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

Acentric chromosome

A

No centromere

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

What happens to acentric chromosomes?

A

Lost due to the lack of centromere

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

Dangerous consequence of inversion

A

Silencing, some genes may be replaced in different chromatin context

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

Translocation

A

The breakage within a chromosome, after which the genetic material is joined in a different chromosome

19
Q

Direct translocation

A

Part of a chromosome is directly translocated into another one

20
Q

Reciprocal translocation

A

An exchange of genetic material, meaning both chromosomes are involved in translocating their genetic material from one another

21
Q

What does translocation not lead to?

A

To the loss of how DNA is transcribed

22
Q

What is nonreciprocal intrachromosomal translocation?

A

Goes from the region of one chromosome into another region of the same chromosome

23
Q

What is nonreciprocal interchromosomal translocation?

A

A region of a chromosome moved into another chromosome

24
Q

What is reciprocal interchromosomal translocation?

A

exchange of genetic material between different chromosomes

25
Q

What does the short arm consist of?

A

Satellite DNA= non-coding repetitive sequences + genes for RNA

26
Q

Metacentric

A

When the centromere is located exactly in the middle

27
Q

Acrocentric

A

When the centromere is moved towards the ends of the chromosome

28
Q

When can Robertsonian translocation occur?

A

When the centromere is moved towards the ends of the chromosome

29
Q

5 acrocentric chromosomes in our genome

A

13
14
15
21
22

30
Q

Down syndrome

A

Due to trisomy 21 or Robertsonian translocation between chromosomes 14 and 21

31
Q

Reciprocal translocation between acrocentric chromosomes

A

could form one chromosome with 2 long arms and a centromere and 2 short arms which is then lost

32
Q

Nullisomic

A

Lack of a pair of homologous chromosomes of one chromosome LETHAL

33
Q

Monosomy

A

one of the 2 homologous chromosome is missing LETHAL

34
Q

Double monosomy

A

two chromosomes are missing, but in 2 different pairs of homologus chromosomes

35
Q

Trisomy

A

one extra chromosome
only non-lethal is trisomy 21

36
Q

Tetrasomy

A

2 extra homologous chromosomes

37
Q

Double tetrasomy

A

2 extra chromosomes on 2 different homologous chromosomes

38
Q

Triploidy

A

A condition which there are 3 copies of chromosomes [XXX or YYY] LETHAL

39
Q

Why are sex chromosome mutations more likely to be compatible with life?

A

Because of chromosome X inactivation

40
Q

Turner Syndrome

A

Women who lack one X chromosome

41
Q

Human aneuploidy

A

abnormally high number of chromosomes

42
Q

Anaphase lagging

A

One chromosome is left behind during separation and is lost during cell division

43
Q

Non-disjunction in meiosis I

A

All of the 4 daughter cells will be chromosomally abnormal

44
Q

Non-disjunction in meiosis II

A

2 will be normal and 2 daughter cells will present aneuploidy

Genetics (29 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions