Test 2: Lecture 20: Factors

Question 1

Developmental (congenital) defects fall into 2 general categories:

Answer 1

genetic
environmental (teratogenic)

Question 2

Variants at a single locus

Answer 2

alleles

Question 3

heterozygous animals show which phenotype

Answer 3

dominant allele

Question 4

phenotype only in homozygous animal

Answer 4

recessive

Question 5

ABO blood groups: AB type is an example of what type of genotype-phenotype alleles

Answer 5

co dominant

Question 6

intermediate phenotype in heterozygous,

Answer 6

partially dominant

Question 7

another name for of partially dominant allele

Answer 7

Haploinsufficiency

Question 8

explain partial/incomplete dominance and what is another name for this?

Answer 8

the heterozygote displays a intermediate phenotype

(one of which is homozygous dominant, and the other of which is homozygous recessive

example: pink flower, stranger thing kid

haploinsufficiency

Question 9

co dominance of alleles

Answer 9

occurs when the phenotypes of both parents are simultaneously expressed in the same offspring organism.

blood typing

Question 10

albinism is an example of ___ . What gene is affected?

Answer 10

autosomal recessive

tyrosinase

Question 11

dwarfism in chickens is a ___ mutation

Answer 11

sex linked

ZZ (male)

ZW (female)

Question 12

myotonia congenita is a mutation in what gene? and what type of mutation

Answer 12

chloride channel

autosomal recessive or dominant

Question 13

X linked muscular dystrophy is a ___ mutation

Answer 13

sex linked XX/XY

dystrophin

Question 14

mutation in RYR1 gene leads to what?

Answer 14

malignant hyperthermia in pigs

dominant negative activity

1 dominant copy and 1 mutated copy C730G

Autosomal dominant mutations in ryanodine receptor (RYR1, a calcium channel in muscle)

Question 15

chromosomal abnormalities can be observed ___

Answer 15

cytologically

(spread out chromosomes on slide and look what is wrong)

Question 16

___ is an uneven number of chromosomes

Answer 16

aneuploidy

Question 17

example of monosomy

Answer 17

turner syndrome (XO)

Question 18

example of trisomy

Answer 18

down syndrome (trisomy 21)

Question 19

chromosomal rearrangements can be :

Answer 19

deletions, inversions, translocations

Question 20

Robertsonian translocations t(1;29)-common and t(14;20)-rare

Animals often viable, but not ___

Answer 20

fertile.

happens in cattle

Question 21

Selection for a single phenotypic trait during breeding can have ___ genetic consequences

Answer 21

deleterious

Question 22

example of single trait selection leading to bad outcome

Answer 22

aggressive rapist roosters

it is believed that continuous selection for large breast size in the population resulted in the inability of the rooster to breed.

Question 23

___ are agents that can cause a permanent alteration to structure or function of an embryo or fetus

Answer 23

teratogen

Question 24

___ are therapeutic drug side effects

Answer 24

iatrogenesis

Question 25

Some examples of teratogens

Answer 25

Environmental pollutants

Therapeutic drug side effects (iatrogenesis)

Poisonous plants and fungus + Infectious agents

Infection (bacterial/viral/parasitic)

Ionizing radiation

Maternal metabolic imbalance (phenylketonurea)

Question 26

Wilson’s six principles of teratology

Susceptibility depends on ___of conceptus

Answer 26

genotype

Question 27

Wilson’s six principles of teratology

Susceptibility varies with ___

Answer 27

developmental stage

Question 28

Wilson’s six principles of teratology

Manifestations of deviant development increase in frequency and degree as ___increases from No Observable Adverse

Answer 28

dosage

Effect Level (NOAEL) to 100: lethality (LD₁₀₀)

Question 29

Four manifestations of deviant development:

Answer 29

death

malformation

growth retardation

functional defect

Question 30

when is the embryo most susceptible to chemical teratogens

Answer 30

gastrulation- organogenesis

Question 31

late developing structures such as ___ remain susceptible until late in gestation

Answer 31

palate

parts of urogenital/repro system

cerebellum

Question 32

mycotoxins are

Answer 32

fungal metabolites

may be found in fungal infected feed

Question 33

How to detect teratogen

Answer 33

HPLC-MS/MS (zearalenone, aflatoxin patulin (high pressure liquid chromatography/tandem mass spectrometry)

Colorimetric enzymatic assays, kits (aflatoxin)

Question 34

latrogenic teratogens are

Answer 34

side effects to therapeutic drugs

Question 35

types of teratogens

Answer 35

environmental pollutants

mycotoxins: fungal metabolites

iatrogenic (side effect to therapeutic drugs

poisonous plants

viruses

bacteria

protozoa

metabolic/ dietary effects

Question 36

immunotolerance

Answer 36

persistent infection of offspring, not always readily noted, helps maintain disease in population!

Question 37

Feline Panleukopenia V. is often ___

Answer 37

parvoviruses often teratogenic

Question 38

Teratogen

excess Vit A can lead to ___

decreased Vit A can lead to ___

Answer 38

(a) deficiency-blindness
(b) excess- cranio-caudal axis and limb formation in embryos.
* RA can alter Hox gene expression, neural crest migration. RA dietary supplementation →CNS defects, cleft palate, thymic aplasia, heart abnormalities*.