DEVELOPMENTAL MALFORMATION 8

Question 1

First Law

Answer 1

a unit of genetic information (gene) is transmitted unchanged
from generation to generation.

Question 2

. Second Law –

Answer 2

– alternate forms of the gene must segregate during gamete
formation and recombine independently in the offspring to provide a 1:2:1
ratio.

Question 3

three modes of genetic defect transmission in animals and
these includes :

Answer 3

1. mutant genes of large effect
2. change in number or morphological state of
   chromosomes
3. additive effects of many genes of small effects but influenced by environmental factors.

Question 3

Third Law

Answer 3

– non-allelic traits do not segregate but assort randomly and recombine with a probability representing the product of their independent
probabilities.

Question 4

Autosomal recessive inheritance

Answer 4

is the most commonly reported
genetic defects in domestic animal species

Question 5

heterozygous

Answer 5

individual contains
different alleles for a given gene

Question 5

homozygous

Answer 5

individual contains a pair
of identical alleles of a given gene

Question 6

exhibit distinct
phenotypic defect.

Answer 6

Autosomal Dominant Inheritance

Question 7

Abnormalities in the number of chromosomes are called

Answer 7

heteroploidy

Question 7

hemizygous

Answer 7

(an individual with possessing only one allele)

Question 7

farm animals that are expressed by autosomal dominant inheritance include :

Answer 7

1. idiopathic epilepsy
2. familial convulsion in cattle.

Question 8

With chromosomal abnormalities, there occur two
types:

Answer 8

numerical abnormality, and structural abnormality

Question 9

heteroploidy and
involves either

Answer 9

polyploidy or aneuploidy

Question 10

individual is born and carries
with its multiples of the haploid number of its chromosomes, the condition is
called

Answer 10

Polyploidy

Question 11

the number may be 69

Answer 11

triploidy

Question 12

92

Answer 12

tetraploidy

Question 13

involves either an increase or decrease in
the normal number of chromosomes without regard to completion of full haploid
set.

Answer 13

Aneuploidy

Question 14

. If there are three sex chromosomes instead of two (e.g.,
XXY, or XYY), the condition is called

Answer 14

trisomy

Question 15

if only one sex chromosome
occur (e.g., OX, OY),

Answer 15

monosomy

Question 16

occur as a result of nondisjunction of chromosomes during
the anaphase stage in meiosis of germ cells or in mitosis at the zygote, and result
to

Answer 16

Heteroploidy

Question 17

the presence of two or more population of cells with different genotypes.

Question 18

In humans, defects in sex chromosome
number are called

Answer 18

gonadal dysgenesis

Question 18

there are chances that fetal sharing of circulation result
to population of cells between twins, resulting to the presence of different genotypes in cell population of one twin. This condition is called

Answer 18

chimerism

Question 19

gonadal dysgenesis, and examples include :

Answer 19

Turner’s syndrome (45, 0X) and Klinefelter’s syndrome (47, XXY).

Question 20

where the fragment becomes attached to another chromosome.

Answer 20

translocation

Question 21

parts of the chromosome exchange places with another and is called

Answer 21

Reciprocal translocation

Question 22

A typical example of translocation was that observed in

Answer 22

Down syndrome

Question 23

where two breaks occurs and a realignment result to a reversal of the order of the chromosome.

Answer 23

inversion of chromosome

Question 24

When a 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,

Answer 24

polygenic inheritance

Question 25

The study of congenital malformations involves a seemingly endless list of unrelated syndromes whose causes are to be found in the ambiguous borderland between environment and genetics

Answer 25

teratology

Question 26

– a twin joined at some portions of the body, with both twins presenting complete parts.

Answer 26

Symmetrical conjoined twin

Question 26

, many are acquired in utero when differentiating cells are destroyed or altered by agents known as

Answer 26

teratogens

Question 26

are agents that affect developing cells and tissue altering its structure, genetic constitution, or both.

Answer 26

Teratogens

Question 26

Symmetrical conjoined twins (also called

Answer 26

Siamese twins

Question 27

(joined at the thorax)

Answer 27

thoracopagus

Question 28

(joined at the ilium of pelvis),

Answer 28

Ileopagus

Question 29

(joined at ischium of pelvis).

Answer 29

Ischiopagus

Question 30

twins joined in some portions of the body, but one twin may be incompletely developed.

Answer 30

Asymmetrical conjoined twins

Question 31

This malformation is a result of problems in placental circulation with compression of umbilical vessels of one of the twins.

Question 32

The attached malformed part of the twin is called a

Answer 32

parasite

Question 33

An example is that of

Answer 33

acardius amorphous, a twin presented without body form and heart

Question 34

a conjoined twin presenting two distinct bodies, united to a common point, but one of the twins is incompletely developed.

Answer 34

Duplication of parts

Question 35

Mechanical constriction of the blastula or gastrula causes this malformation

Question 35

with two heads

Answer 35

dicephalus monster

Question 36

– imperfect closure of vertebra

Answer 36

Spina bifida

Question 36

(with two hind parts).

Answer 36

dipygus monster

Question 37

– failure of the brain to develop

Answer 37

Anencephaly

Question 38

– imperfect closure of the cranium

Answer 38

Cranioschisis

Question 39

– brain tissue protrudes in a hole of the skull

Answer 39

Cephalocele

Question 40

cerebrospinal fluid is produced but not drained

Answer 40

Hydrocephalus

Question 41

complete failure of the spinal cord development

Answer 41

Amyelia

Question 42

– dilatation of the central spinal canal

Answer 42

Hydromyelia

Question 43

cavitations of the spinal cord

Answer 43

Syringomyelia

Question 44

Defects in Head and Neck

Question 45

– split nose

Answer 45

nasoschisis

Question 45

open palate

Answer 45

palatoschisis

Question 45

slit upper lip;

Answer 45

chieloschisis

Question 46

a developmental defect of frontal and nasal bones with two eyes developing in one socket; a

Answer 46

cyclopia

Question 47

absence of lower jaw,

Answer 47

agnathia

Question 47

failure of the facial structures to develop

Answer 47

aprosopus

Question 48

very small jaw)

Answer 48

micrognathia

Question 48

Abnormalities in Hind Limbs

Question 49

failure of limb development

Answer 49

sympodia

Question 50

Abnormalities in Tissues or Organs

Question 51

– fused hindlimbs

Answer 51

symelia

Question 52

(no anal opening)

Answer 52

atresia ani

Question 53

a female born co-twin to a male that have altered gonadal development due to blood exchanges in utero)

Answer 53

intersex

Question 54

Defects in Skeletogenesis

Question 55

where the skeleton is missing or failed to develop

Answer 55

chondrodystrophia foetalis

Question 55

there occur failure of cartilage formation and subsequent improper ossification resulting to short limbs

Answer 55

achondrodysplasia

Question 55

are abnormal mixtures of tissues indigenous to their location

Answer 55

Hamartomas

Question 55

example is nevus or mole; angioma and some lipoma

Question 56

– is a disease in which an animal is born with flexed, absolutely rigid limbs but this is a primary problem not with bones or joints but ratherwith innervation of muscles because of dysraphism in the spinal cord.

Answer 56

Arthrogryposis