問題一覧
1
The study of developmental anomalies.
Teratology
2
Susceptibility to teratogens is variable.
True
3
Susceptibility to teratogens is the same for each embryologic stage.
False
4
Teratogenic drugs inhibit crucial enzymes or receptors; however, they may not interfere with the formation of mitotic spindles or block energy production.
False
5
Theoretically, this means that each teratogen should have a “safe” dose, below which no teratogenesis occurs.
True
6
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
7
The fetus may possibly develop syphilis if the mother became infected in the 2 years before the pregnancy.
True
8
Positions of constriction in a chromosome.
Centromere
9
Using a stain such as Giemsa, chromosomes are classified according to their length and a certain structure called..
Centromere
10
The point at which the two identical strands of chromosomal DNA, called sister chro-matids, attach to each other during mitosis.
Centromere
11
The centromere is exactly in the middle.
Metacentric
12
The chromosome divides into a short arm (p, from French, petit) and a long arm (q, the next letter in the alphabet).
Submetacentric
13
A chromosome where the centromere is not central and is instead located near the end of the chromosome.
Acrocentric
14
Having the centromere at the end of the chromosome.
Telocentric
15
The Y chromosome is acrocentric.
True
16
These chromosome bands are highlighted using Giemsa stain
G bands
17
These chromosome bands stain with Giemsa and fluoresce when treated with quinacrine
Q bands
18
On appropriate staining, these chromosome bands present as reverse images of G and Q bands.
R bands
19
This is a method for staining centromeres and other portions of chromosomes containing constitutive heterochromatin.
C bands
20
Inactive X chromosome
Barr body
21
This technique stains the terminal ends of chromosomes.
T bands
22
The study of chromosomes and their abnormalities.
Cytogenetics
23
The current system of classification in cytogenetics.
International System for Human Cytogenetic Nomenclature
24
During normal meiosis, homologous chromo-somes (e.g., two chromosomes 1) form pairs, called..
Bivalents
25
Exchanges involving nonhomologous chromosomes
Translocation
26
Two major types of chromosomal translocation.
Robertsonian translocation, Reciprocal translocation
27
Refers to exchange of acentric chromosomal segments between different (nonhomologous) chromosomes.
Reciprocal translocation
28
A reciprocal translocation is balanced, regardless if there is loss of genetic material.
False
29
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
30
Balanced reciprocal translocations can be inherited for many generations.
True
31
Offspring of carriers of balanced translocations will have balanced karyotypes and may not show severe phenotypic abnormalities.
False
32
Also known as centric fusion, involves the centromere of acrocentric chromosome
Robertsonian translocation
33
Loss of a portion of a chromosome and involves either a ter-minal or an intercalary (middle) segment.
Chromosomal deletion
34
Name the chromosomal abnormalities depicted in the picture. Write your answer according to its order:
Deletion, Translocation, Inversion, Robertsonian translocation, Isochromosomal translocation, Ring formation
35
Disease associated with deletion
Cri du chat syndrome
36
Genetic disease which the short arm of chromosome 5 is deleted.
Cri du chat syndrome
37
Genetic disease associated with deletions in the short arm of chro-mosome 11.
Wilms tumor aniridia syndrome
38
A process in which a chromosome breaks at two points, the affected segment inverts and then reat-taches.
Chromosomal inversion
39
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
40
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
41
The most important clinical condition involving isochromosomes in which 15% of those affected have an isochromosome of the X chromosome.
Turner syndrome
42
Failure of paired chromosomes or chromatids to separate and move to opposite poles of the spindle at anaphase, during mitosis or meiosis.
Nondisjunction
43
Numerical chromosomal abnormal-ities arise primarily from nondisjunction.
True
44
The causes of chromosomal aberrations are largely known.
False
45
Most major chromosomal abnormalities are incompatible with life.
True
46
Up to 15% of spontaneous abortions have a chromosomal abnormality.
False
47
Karyotypes are described sequentially by:
.
48
Designation for short arm of chromosomes
p
49
Designation for long arm of chromosomes
q
50
Symbol for the addition and loss of chromosomal material respectively.
+, -
51
How is the loss (deletion) of part of a chromosome typically designated?
del
52
What is the notation for translocation in chromosomal aberrations?
t(brackets) or t followed by brackets containing the involved chromosomes
53
Numerical autosomal aberrations in liveborn infants are virtually all trisomies.
True
54
Karyotype for male with trisomy 21 (Down syndrome)
47, XY, +21
55
Karyotype for Female carrier of fusion-type translocation between chromosomes 14 and 21
45, XX,-14, -21 + t(14q21q)
56
Karyotype for Cri du chat syndrome (male) with deletion of a portion of the short arm of chromosome 5
46, XY, del(5p)
57
Karyotype for male with ring chromosome 19
46, XY, r(19)
58
Turner syndrome with monosomy X
45, X
59
Mosaic Klinefelter syndrome
46,XY/47,XXY
60
Trisomy 21 is the most common cause of mental retardation.
True
61
List some of the clinical features of Down Syndrome
Growth failure, Mental retardation , Flat occiput, Congenital heart disease, Dysplastic ears
62
Children with Down syndrome are invariably mentally retarded.
True
63
Also known as testicular dysgenesis, there are one or more X chromosomes beyond the normal male XY complement (XXY).
Klinefelter syndrome
64
This syndrome is a prominent cause of male hypogonadism and infertility.
Klinefelter syndrome
65
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
66
The spectrum of abnormalities that results from complete or partial X chromosome monosomy in a phenotypic female.
Turner syndrome
67
Determined by two copies of the same gene, called alleles, located at the same locus on two homologous chromosomes.
Mendelian trait
68
Four Classifications of Mendelian Traits
Autosomal dominant, Autosomal recessive, Sex-linked dominant, Sex-linked recessive
69
These are traits or disorders that occur when a mutation is present in just one copy of a gene.
Autosomal dominant
70
These traits or disorders occur when both copies of a gene are present for a condition to be expressed.
Autosomal recessive
71
The trait must be present in both copies of the gene for a person to have the condition.
Sex-linked recessive
72
Mutation with replacement of one base by another
Point mutation
73
New codon with the mutation still codes for the same amino acid.
Synonymous mutation