Brainscape's Knowledge GenomeTM

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


See full index

Cytogenetics > Lesson 4 : CHROMOSOMES > Flashcards

Lesson 4 : CHROMOSOMES Flashcards

1
Q

Primarily consist of DNA and protein.

A

CHROMOSOMES

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

Essential parts of Chromosomes

A

■ Telomeres
■ Origins of replication sites
■ Centromere

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

Largest constriction of the chromosome and where spindle fibers attach.

A

CENTROMERE

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

Bases that form the centromere are repeats of a

A

171-base DNA sequence

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

_______ is passed to next generation.

A

CENP-A

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

Chromosome region between the centromere and telomeres.

A

SUBTELOMERE

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

Subtelomere consists of ____ to ____ bases.

A

8000 to 300,000

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

Subtelomere contains at least ____ protein-encoding genes. About 50% are multigene families that include _______.

A

500
pseudogenes

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

Define KARYOTYPE

A

● Chromosome chart.
● Major clinical tool.
● Displays chromosomes arranged by size and structure.

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

Humans have ___ chromosome types

_____ are numbered 1-22 by size
______ are X and Y

A

Humans have 24 chromosome
types.

■ Autosomes are numbered 1-22 by size
■ Sex chromosomes are X and Y

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

Karyotype Benefits

A

● Confirm a clinical diagnosis.
● Reveal effects of environmental toxins.
● Clarify evolutionary relationships.

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

CENTROMERE POSITIONS

A

● Telocentric - At the tip.
● Acrocentric - Close to center.
● Submetacentric - Off-center.
● Metacentric - At center.

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

○ Fetal tissue
○ Adult tissue

A

○ Fetal tissue
■ Amniocentesis
■ Chorionic villi sampling
■ Fetal cell sorting
■ Chromosome microarray analysis

○ Adult tissue
■ White blood cells
■ Skin-like cells from cheek swab

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

Chromosomes are extracted, then stained with a combination of _________ and _______

A

dyes and DNA probes

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

_________ detects about ______ of the more than ______ known chromosomal and
biochemical problems.

A

AMNIOCENTESIS
1000
5000

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

In Amniocentesis Ultrasound is used to ___________.

A

follow the needle’s movement

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

Define CHORIONIC VILLUS SAMPLING

A

● Performed during 10-12th week of pregnancy.
● Provides earlier results than amniocentesis.
● Does not detect metabolic problems.
● Has greater risk of spontaneous abortion.

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

____________ correspond to _____ copies of ___________.

A

Fluorescent dots
three
chromosome 21

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

● Schematic chromosome map.
● Indicates chromosome arms (p or q)and major regions delineated by banding patterns

A

IDEOGRAM

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

Karyotype may be abnormal in:

A

○ Chromosome number
○ Chromosome structure

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

Abnormal chromosomes account for at least ____ of ____________.

A

50%
spontaneous abortions.

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

People are being diagnosed with chromosomal abnormalities due to _______________.

A

improved technology

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

Extra chromosome sets

A

Polyploidy

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

An extra or missing chromosome

A

Aneuploidy

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

One chromosome absent

A

Monosomy

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

One chromosome extra

A

Trisomy

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

___________ and __________ proved direct detection of _____________.

A

Amniocentesis and chorionic villus sampling
extra chromosomes

28
Q

____________ offer an indirect method

A

Maternal serum markers

29
Q

Cell-free DNA Testing can ve performed at least __ weeks into pregnancy

A

10 weeks

30
Q

In cell-free DNA Testing up to 20 percent of these pieces
come from the ________, and thus
represent the ____________.

A

placenta
fetal genome

31
Q

______ cells have three sets of chromosomes. Produced by:

A

Triploid
■ Fertilization of one egg by two sperm
■ Fusion of haploid and diploid cells

32
Q

Those born with aneuploidy are more likely to have____________ rather than _______.

A

an extra chromosome (trisomy)
a missing one (monosomy)

33
Q

Aneuploidy arises during _______, producing groups of _________ with the extra or missing chromosomes.

A

mitosis
somatic cells

34
Q

Individual with two chromosomally-distinct cell populations is called a _________.

A

mosaic

35
Q

_________ cease developing as embryos or fetuses.

A

Autosomal aneuploids

36
Q

Frequently seen _________ in newborns are those of chromosomes ___,____, and ___.○ Carry fewer genes than other autosomes.

A

trisomies
21, 18, and 13

37
Q

● Most common trisomy among newborns.
● Distinctive facial and physica lproblems.

A

DOWN SYNDROME

38
Q

TRISOMY __
● Due to nondisjunction in meiosis II cccc in oocyte and generally do not survive
.● Serious mental and physical disabilities.
● Distinctive feature - Oddly clenched fists.

A

TRISOMY 21
EDWARDS SYNDROME

39
Q

TRISOMY ___

● Very rare and generally do not survive 6 months.
● Serious mental and physical disabilities.
● Distinctive feature - eye fusion.

A

TRISOMY 13
PATAU SYNDROME

40
Q

TRISOMY __

● One in 2500 female births.
● 99% of affected fetuses die in utero.
● Features:
○ Short stature
○ Webbing at back of neck
○ Incomplete sexual development (infertile)
○ Impaired hearing
● Individuals who are mosaics may have children.

A

TRISOMY 13
TURNER (XO) SYNDROME

41
Q

TRISOMY __

● One in 1000 female births.
● Few modest effects on phenotype include tallness, menstrual irregularities, and a slight impact on intelligence.
● X inactivation of two X chromosomes occurs and cells have two Barrbodies.
● May compensate for the presence of extra X.

A

TRISOMY 13
TRIPLO-X SYNDROME

42
Q

TRISOMY __

● One in 500 male births.
● Phenotypes include:
○ Incomplete sexual development
○ Rudimentary testes and prostate
○ Long limbs, large hands, and feet
○ Some breast tissue development
● Common cause of male infertility

A

TRISOMY 13
KLINEFELTER (XXY) SYNDROME

43
Q

TRISOMY __

● Arises due to unusual oocyte and sperm.
● Associated with more severe behavioral problems than Klinefelter syndrome.
○ AAD, obsessive-compulsive
disorder, learning disabilities
● Individuals are infertile.
● Treated with testosterone

A

TRISOMY 13
XXYY SYNDROME

44
Q

TRISOMY __

● One in 1000 male births
● 96% are phenotypically normal
● Modest phenotypes
○ Great height
○ Acne
○ Speech and reading
disabilities.
● Studies suggest increase in aggressive behaviors are not supported.

A

TRISOMY 13
JACOBS (XYY) SYNDROME

45
Q

Missing genetic segment from a chromosome.

A

DELETION

46
Q

Deletion is often not inherited, rather they arise

A

de novo

47
Q

Larger deletions increase the likelihood that there will be an ______

A

associated phenotype

48
Q

Deletion 5p

A

Cri-du-chat (cat cry) syndrome.

49
Q

● Presence of an extra genetic segment on a chromosome.
○ Often not inherited.
○ Rather they arise ____.

A

DUPLICATION
de novo

50
Q

Duplication’s effect on the phenotype is generally dependent on their

A

size

51
Q

Two nonhomologous chromosomes exchange segments.

A

TRANSLOCATIONS

52
Q

Translocations types :

A

○ Robertsonian Translocation
○ Reciprocal Translocation

53
Q

Two nonhomologous acrocentric chromosomes break at the centromere and their long arms fuse.

A

ROBERTSONIAN TRANSLOCATIONS

54
Q

Translocation carriers have __ chromosomes. Produce _________ gametes.

A

45
unbalanced

55
Q

__ of Down syndrome results from a ________________ between chromosomes ___ and _____.

A

5%
Robertsonian translocation
21 and 14.

56
Q

Tends to recur in families, who also have more risk of spontaneous abortions.

A

TRANSLOCATION DOWN SYNDROME

57
Q

Two nonhomologous chromosomes exchange parts

A

RECIPROCAL TRANSLOCATIONS

58
Q

_________ : Chromosome segment that is flipped in orientation. ______ cause health problems probably due to ______ at the _______. May impact ___________.

A

INVERSIONS
5-10%
disruption of genes
breakpoints
meiotic segregation

59
Q

Inverted region does not include centromere.

A

Paracentric inversion

60
Q

Inverted region includes centromere

A

Pericentric inversion

61
Q

● Chromosomes with identical arms.
● Formed when centromeres divide along the incorrect plane during meiosis.

A

ISOCHROMOSOMES

62
Q

● Occur in 1 of 25,000 conceptions.
● Arise when telomeres are lost and sticky chromosome ends fuse.
● Genes can be lost or disrupted causing symptoms.

A

RING CHROMOSOMES

63
Q

TRAITS INHERITED ON SEX CHROMOSOMES

Passed from fathers to sons only.

A

Y-Linked Traits

64
Q

TRAITS INHERITED ON SEX CHROMOSOMES

○ Passed from mother to son because he inherits his X from his mother and his Y from his father.
○ May be dominant or recessive.
○ X-linked dominant traits are more devastating to males.

A

X-Linked Traits

65
Q

Shuts off one X chromosome in each cell in female mammals making them mosaics for heterozygous X-linked genes.

A

X INACTIVATION

66
Q

In humans, it can be used to identify carriers of some X-linked
diseases such as _______ in which an affected boy has ___________.

A

Lesch-Nyhan syndrome
cerebral palsy

Cytogenetics (4 decks)

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