animal breeding and genetics

Question 1

domestication

Answer 1

process of adapting wild plants and animals to live in association with humans

Question 2

when did live stock domestication start

Answer 2

~10,000 years ago

Question 3

animal domestication and production requirements

Answer 3

-feeding (nutrition)
-animal health
-selection of stock (breeding and genetics)

Question 4

in the beginning what kind of traits were selected for

Answer 4

-observable ones (phenotype)
-color, size, speed, etc

Question 5

selective breeding

Answer 5

-improve growth, performance, ect

Question 6

preventative medicine

Answer 6

-cull decisions (cull doesnt always mean kill)
-few genetic diseases are treatable

Question 7

individuals vs herd

Answer 7

-individual- can be culled and change herd influence
-herd- influence made by mating systems, selection methods, selection techniques

Question 8

what are the majority of clients seeking genetic advice

Answer 8

purebred breeders

Question 9

what is the primary product of purebred producers

Answer 9

-genes
-bull, bohr, semen, embryo

Question 10

=/

Answer 10

congenital (present at birth)

Question 11

=

Answer 11

inherited (not present at birth, have but shows later, huntingtons disease)

Question 12

~

Answer 12

familial (cancer or diabeties, may be present but lifestyle can impact)

Question 13

what are the different kinds of patterns of inheritance

Answer 13

-single gene
-chromosomal
-multifactorial
-teratogenic

Question 14

single gene inheritance

Answer 14

There are five basic modes of inheritance for single-gene diseases: autosomal dominant, autosomal recessive, X-linked dominant, X-linked recessive, and mitochondrial

Question 15

chromosomal gene inheritance

Answer 15

inherit large chunks of DNA

Question 16

multifactorial gene inheritance

Answer 16

complex genetics plus environment (diabetes)

Question 17

teratogenic inheritance

Answer 17

usually caused by agent or toxin

Question 18

what is the importance of family history

Answer 18

gives more power to find cause of trait

Question 19

what are some helpful things to know for a family tree

Answer 19

-age of parents
-number of previous offspring (normal and abnormal)
-sex of affecteds
-number of miscarriages and still births
-breed

Question 20

triangle pedigree symbol

Answer 20

sex unspecified or ambiguous

Question 21

solid black dot or square family tree symbol

Answer 21

female affected or male affected

Question 22

cross through family tree symbol

Answer 22

dead

Question 23

circle with small black dot in it family tree symbol

Answer 23

carrier of X-linked

Question 24

half black half white circle family tree symbol

Answer 24

heterozygous female carrier (one allele affected one normal)

Question 25

autosomal single gene inheritance

Answer 25

-on non sex chromosome
-dominant and recessive
-if dominant is present its always expressed
-need two copies of recessive to produce phenotype

Question 26

sex linked single gene inheritance

Answer 26

-X and Y in mammals, Z and W in birds
-dominant
-recessive

Question 27

what are the heterogenemic sex in birds and mammals

Answer 27

birds=female
mammals=male

Question 28

autosomal dominant generalizations

Answer 28

-most non-enzyme protein disorders
-veritable expressivity (degree)(light dimmer)
-reduced or incomplete penetrance (present or absent)(light switch)
-many are the result of a new mutation
-homozygote is often lethal

Question 29

variable expressivity (degree) example

Answer 29

-manx cat
-show quality “ideal” manx are tailless
-but some are missing only some tail vertebrae
-genotype: Mm

-belt in galloway cattle
-dominant allele for presence of belt
-variable expression

Question 30

reduced penetrance (present or absent)

Answer 30

-full
-all individuals with the allele express the phenotype

-reduced
-not all individuals show phenotype
-i.e. 70% penetrance=70% with the allele express the phenotype

Question 31

reduced penetrance canine gallbladder mucoceles

Answer 31

-dominant but doesn’t always show
-dominant with reduced penetrance
-rare disease that affects certain dog breeds (sheltie, cairn terrier, Pomeranian, etc)

Question 32

autosomal dominant generalization example

Answer 32

-many are the result of a new mutation
-polled in cattle- more than one polled mutation
-80kb duplication in holstein-friesian cattle
-202 bp insertion/deletion (indel) in beef breeds
-homozygote is often lethal
-manx cat, mexican hairless, overo horse, camarillo white horse