LN 08 (Developmental Malformation) Flashcards
1
Q
simply imply that the individual is born with the defect and has no reference to it being hereditary or not
A
congenital defects
2
Q
How is hereditary defects not always congenital?
A
some are made manifest later in life of the individual
3
Q
physical expression of a trait
A
phenotype
4
Q
genetic constitution of an organism
A
genotype
5
Q
unit of genetic information (gene) is transmitted unchanged from generation to generation
A
first law
6
Q
alternate forms of the gene must segregate during gamete formation and recombine independently in the offspring to provide a 1:2:1 ratio
A
second law
7
Q
alternate form of gene
A
alelle
8
Q
non-allelic traits do not segregate but assort randomly and recombine with a probability representing the product of their independent probabilities
A
third law
9
Q
Three modes of genetic defect transmission
A
- Mutant genes of large effect
- Change in number or morphological state of chromosomes
- Additive effects of many genes of small effects but influenced by environmental factors
10
Q
are expressed according to the foregoing laws of inheritance
A
mutant genes of large effect
11
Q
most commonly reported
genetic defects in domestic animal species
A
autosomal recessive inheritance
12
Q
most commonly reported
genetic defects in humans
A
autosomal dominant inheritance
13
Q
individual contains a pair
of identical alleles of a given gene
A
homozygous
14
Q
individual contains different alleles for a given gene
A
heterozygous
15
Q
ratio between those affected and not affected in any given mating is
A
three phenotypic normal to one affected individual, or 25% chances
16
Q
congenital tremor
A
pig
17
Q
cerebellar atrophy
A
sheep
18
Q
cerebellar hypoplasia
A
cattle
19
Q
cranium bifidum
A
pig
20
Q
congenital hydrocephalus
A
cattle
21
Q
atresia ani
A
pig
22
Q
chediak-higashi syndrome
A
cattle, horse
23
Q
combined immunodefiecency
A
horse
24
Q
inherited goiter
A
sheep
25
familial polycythemia
cattle
26
congenital porphyria
cattle, pig
27
Cases reported in farm animals that are expressed by autosomal dominant
inheritance include
1. idiopathic epilepsy
2. familial convulsion in cattle
28
heterozygote affected animal mates with a homozygote animal, each offspring has ___ risk of being affected
50%
29
both parents are heterozygote affected, the risk that the offspring produced are affected increases to
75%
30
Breeding patterns that result to a defect observed to occur in the males
only tend to suggest that the defect is
Y linked
31
Two types of chromosomal abnormalities
1. numerical abnormality
2. structural abnormality
32
Abnormalities in the number of chromosomes are called
heteroploidy
33
individual is born and carries with its multiples of the haploid number of its chromosomes
polyploidy
34
involves either an increase or decrease in the normal number of chromosomes without regard to completion of full haploid set
aneuploidy
35
there are three sex chromosomes instead of two
trisomy
36
f only one sex chromosome
occur (e.g., OX, OY)
monosomy
37
result of nondisjunction of chromosomes during
the anaphase stage in meiosis of germ cells or in mitosis at the zygote
heteroploidy
38
heteroploidy results to, ____, which is the presence of two or more population of cells with different
genotypes
mosaicism
39
In ruminants, fraternal twinning results to the presence of different
genotypes in cell population of one twin in a condition known as
chimerism (due to fetal sharing of circulation)
40
example of chimerism
freemartin
41
In humans, defects in sex chromosome number are called
gonadal dysgenesis
42
gonadal dysgenesis examples
1. Turner's syndrome (45, 0X)
2. Klinefelter's syndrome (47, XXY)
43
fragment of chromosomes becomes attached to another chromosome
translocation
44
parts of the chromosome exchange places with another
reciprocal translocation
45
example of translocation in humans
Down syndrome
46
two breaks occurs and a realignment result to a reversal of the order of
the chromosome
inversion of chromosome
47
defect is governed by the additive effect of two or more genes of small effect but is conditioned by non-genetic environmental influences and is expressed
polygenic inheritance
48
One of the best-studied diseases due to polygenic inheritance
diabetes
49
defect where there is a deficiency of insulin, and therefore there occur persistent hyperglycemia
diabetes mellitus
50
study of congenital malformations
teratology
51
malformation acquired in utero when differentiating cells are destroyed or altered by agents known as
teratogens
52
agents that affect developing cells and tissue altering its structure, genetic constitution, or both
teratogens
53
includes trauma, ionizing radiation, heat, cold and
pressure
physical agents
54
includes drugs, chemicals, hormones, vaccines,
toxins and toxicant
chemical agents
55
metazoan, bacteria, fungi, protozoan, including
viruses
biological agents
56
teratogenic agent that causes Amelia (absence of limbs) in affected humans
thalidomide
57
twin joined at some portions of the body, with both twins presenting complete parts
symmetrical conjoined twin
58
named by the anatomic location of union, and carry the suffix “pagus”
Symmetrical conjoined twins (also called
Siamese twins)
59
basic mechanism for symmetrical conjoined twin formation
splitting of the zygote
resulting to two blastoderms developing from a single ovum
60
joined at the thorax
thoracopagus
61
joined at the ilium of pelvis
Ileopagus
62
joined at ischium of pelvis
ischiopagus
63
Examples of symmetrical conjoined twin
1. Thoracopagus
2. Ileopagus
3. Ischiopagus
64
twins joined in some portions of the body, but one twin may be incompletely developed
asymmetrical conjoined twins
65
malformation is a result of
problems in placental circulation with compression of umbilical vessels of one of the twins
Asymmetrical conjoined twins
66
attached malformed part of the twin is called
parasite
67
a twin presented without body form and heart
acardius amorphous
68
acardius amorphous is an example of
Asymmetrical conjoined twins
69
a conjoined twin presenting two distinct bodies, united to a common point, but one of the twins is incompletely developed
duplication of parts
70
What causes duplication of parts?
Mechanical constriction of the blastula or gastrula
71
Examples of duplication of parts
1. Dicephalus monster (2 heads)
2. Dipygus monster (2 hind parts)
72
imperfect closure of vertebra
spina bifida
73
failure of the brain to develop
anencephaly
74
imperfect closure of the cranium
cranioschisis
75
brain tissue protrudes in a hole of the skull
cephalocele
76
cerebrospinal fluid is produced but not drained
hydrocephalus
77
complete failure of the spinal cord development
amyelia
78
dilatation of the central spinal canal
hydromyelia
79
cavitations of the spinal cord
syringomyelia
80
palatoschisis
open palate
81
chieloschisis
slit upper lip
82
nasoschisis
split nose
83
a developmental defect of
frontal and nasal bones with two eyes developing in one socket
cyclopia or cebocephalia
84
failure of the facial structures to develop
aprosopus
85
absence of lower jaw
agnathia
86
very small jaw
micrognathia
87
strangulation of the developing limb with umbilical vessels leading to amputation or fusion
abnormalities in hind limb
88
failure of limb development
sympodia
89
fused hindlimbs
symelia
90
thorachoschisis
sternal fissure
91
omphaloschisis
opening at umbilicus
92
gastroschisis
opened walls of stomach
93
incomplete development of ventral body walls where affected animals show exposed visceral organs
schistosomus reflexus
94
a female born co-twin to
a male that have altered gonadal development due to blood exchanges in utero
intersex or hermaphroditism
95
failure of cartilage formation and subsequent improper ossification
resulting to short limbs
achondrodysplasia
96
skeleton is missing or failed to develop
chondrodystrophia
97
abnormal mixtures of tissues indigenous to their location
hamartomas
98
consist of tissues that are foreign to the area
teratoma
99
disease in which an animal is born with flexed, absolutely rigid limbs but this is a primary problem not with bones or joints but rather with innervation of muscles because of dysraphism in the spinal cord
arthrogryposis
100
Defects in Skeletogenesis
1. achondrodysplasia
2. chondrodystrophia
101
Abnormalities in Tissues or Organs
1. foramen ovale in the heart
2. atresia ani (no anal opening)
3. intersex or hermaphroditism
102
Defects in Ventral Body Walls
1. thoracoschisis
2. omphaloschisis
3. gastroschisis
4. schistosomus
103
Abnormalities in Hind Limbs
1. sympodia
2. symelia
104
Some structures fail to fuse at median plane:
1. palatoschisis
2. chieloschisis
3. nasoschisis
105
defects in the development of the jaws
1. agnathia
2. micrognathia
106
often implicated in cases of
congenital malformation
1. Drugs
2. Viruses
3. Plant toxins
107
cells in the developing fetus
are most susceptible to the adverse effects of teratogens during
Cellular differentiation and organogenesis
108
Plant toxins proven to cause malformations
1. Coniine and gamma coniceine
2. Nicotine
3. Undefined alkaloid of Veratrum Californicum
