問題一覧
1
The study of chromosomes and their abnormalities.
Cytogenetics
2
The trait must be present in both copies of the gene for a person to have the condition.
Sex-linked recessive
3
Theoretically, this means that each teratogen should have a “safe” dose, below which no teratogenesis occurs.
True
4
The chromosome divides into a short arm (p, from French, petit) and a long arm (q, the next letter in the alphabet).
Submetacentric
5
What is the notation for translocation in chromosomal aberrations?
t(brackets) or t followed by brackets containing the involved chromosomes
6
Karyotype for Female carrier of fusion-type translocation between chromosomes 14 and 21
45, XX,-14, -21 + t(14q21q)
7
Positions of constriction in a chromosome.
Centromere
8
Using a stain such as Giemsa, chromosomes are classified according to their length and a certain structure called..
Centromere
9
These chromosome bands stain with Giemsa and fluoresce when treated with quinacrine
Q bands
10
These traits or disorders occur when both copies of a gene are present for a condition to be expressed.
Autosomal recessive
11
Designation for long arm of chromosomes
q
12
Determined by two copies of the same gene, called alleles, located at the same locus on two homologous chromosomes.
Mendelian trait
13
Karyotype for Cri du chat syndrome (male) with deletion of a portion of the short arm of chromosome 5
46, XY, del(5p)
14
Susceptibility to teratogens is the same for each embryologic stage.
False
15
This drug was found not to be teratogenic in mice and rats but caused complex human malformations when many pregnant women ingested it in their first trimester of pregnancy.
Thalidomide
16
Also known as centric fusion, involves the centromere of acrocentric chromosome
Robertsonian translocation
17
Refers to exchange of acentric chromosomal segments between different (nonhomologous) chromosomes.
Reciprocal translocation
18
Designation for short arm of chromosomes
p
19
The spectrum of abnormalities that results from complete or partial X chromosome monosomy in a phenotypic female.
Turner syndrome
20
The point at which the two identical strands of chromosomal DNA, called sister chro-matids, attach to each other during mitosis.
Centromere
21
Balanced translocations are not generally associated with loss of genes or disruption of vital gene loci, so most carriers of balanced translocations are phenotypically nor-mal.
True
22
Balanced reciprocal translocations can be inherited for many generations.
True
23
Mutation with replacement of one base by another
Point mutation
24
Disease associated with deletion
Cri du chat syndrome
25
Karyotypes are described sequentially by:
.
26
Children with Down syndrome are invariably mentally retarded.
True
27
Teratogenic drugs inhibit crucial enzymes or receptors; however, they may not interfere with the formation of mitotic spindles or block energy production.
False
28
These chromosome bands are highlighted using Giemsa stain
G bands
29
Numerical autosomal aberrations in liveborn infants are virtually all trisomies.
True
30
This technique stains the terminal ends of chromosomes.
T bands
31
Two major types of chromosomal translocation.
Robertsonian translocation, Reciprocal translocation
32
During normal meiosis, homologous chromo-somes (e.g., two chromosomes 1) form pairs, called..
Bivalents
33
The centromere is exactly in the middle.
Metacentric
34
Karyotype for male with trisomy 21 (Down syndrome)
47, XY, +21
35
Loss of a portion of a chromosome and involves either a ter-minal or an intercalary (middle) segment.
Chromosomal deletion
36
The fetus may possibly develop syphilis if the mother became infected in the 2 years before the pregnancy.
True
37
The most important clinical condition involving isochromosomes in which 15% of those affected have an isochromosome of the X chromosome.
Turner syndrome
38
Mosaic Klinefelter syndrome
46,XY/47,XXY
39
A chromosome where the centromere is not central and is instead located near the end of the chromosome.
Acrocentric
40
The study of developmental anomalies.
Teratology
41
Inactive X chromosome
Barr body
42
How is the loss (deletion) of part of a chromosome typically designated?
del
43
A process in which a chromosome breaks at two points, the affected segment inverts and then reat-taches.
Chromosomal inversion
44
Name the chromosomal abnormalities depicted in the picture. Write your answer according to its order:
Deletion, Translocation, Inversion, Robertsonian translocation, Isochromosomal translocation, Ring formation
45
Also known as "supermale", is a genetic condition found in about 1 in 1000 male newborns, characterized by an extra Y chromosome, leading to features such as tall stature, cystic acne, and some motor and language development issues.
XYY male
46
Exchanges involving nonhomologous chromosomes
Translocation
47
On appropriate staining, these chromosome bands present as reverse images of G and Q bands.
R bands
48
Failure of paired chromosomes or chromatids to separate and move to opposite poles of the spindle at anaphase, during mitosis or meiosis.
Nondisjunction
49
The current system of classification in cytogenetics.
International System for Human Cytogenetic Nomenclature
50
Formed by a break involving both telomericends of a chromosome, deletion of the acentric fragments and end-to-end fusion of the remaining centric portion of the chromosome.
Ring chromosome
51
Up to 15% of spontaneous abortions have a chromosomal abnormality.
False
52
Trisomy 21 is the most common cause of mental retardation.
True
53
Most major chromosomal abnormalities are incompatible with life.
True
54
Female preponderance, micrognathia, congenital heart disease, horseshoe kidney, deformed fingers
Chromosome 18 (47, XX or XY, +18: 1/8000)
55
This is a method for staining centromeres and other portions of chromosomes containing constitutive heterochromatin.
C bands
56
Offspring of carriers of balanced translocations will have balanced karyotypes and may not show severe phenotypic abnormalities.
False
57
Turner syndrome with monosomy X
45, X
58
Having the centromere at the end of the chromosome.
Telocentric
59
List some of the clinical features of Down Syndrome
Growth failure, Mental retardation , Flat occiput, Congenital heart disease, Dysplastic ears
60
Susceptibility to teratogens is variable.
True
61
A reciprocal translocation is balanced, regardless if there is loss of genetic material.
False
62
Symbol for the addition and loss of chromosomal material respectively.
+, -
63
Karyotype for male with ring chromosome 19
46, XY, r(19)
64
New codon with the mutation still codes for the same amino acid.
Synonymous mutation
65
Genetic disease associated with deletions in the short arm of chro-mosome 11.
Wilms tumor aniridia syndrome
66
This syndrome is a prominent cause of male hypogonadism and infertility.
Klinefelter syndrome
67
These are traits or disorders that occur when a mutation is present in just one copy of a gene.
Autosomal dominant
68
1. A type of chromosomal inversion which results from breaks on opposite sides of the centromere. 2. A type of chromosomal inversion which involves breaks on the same arm of the chromosome
Pericentric inversion, Paracentric inversion
69
Four Classifications of Mendelian Traits
Autosomal dominant, Autosomal recessive, Sex-linked dominant, Sex-linked recessive
70
Also known as testicular dysgenesis, there are one or more X chromosomes beyond the normal male XY complement (XXY).
Klinefelter syndrome
71
Genetic disease which the short arm of chromosome 5 is deleted.
Cri du chat syndrome
72
The Y chromosome is acrocentric.
True
73
The causes of chromosomal aberrations are largely known.
False