Last Quiz Flashcards
This is a mathematical model on the genotypic and allelic frequencies of a population
Hardy Weinberg law
What is the formula for the h-w law
P2 (squared) + 2pq+ q2 (squared)
Population is large
Randomly mating
Not affected by mutations, migration, or natural selection
Hardy Weinberg equilibrium
GENE FREQUENCY
When you mate two roan shorthorns what is the possible outcome ratio
What is the frequency
1 RR : 2 RW : 1 WW
R = 0.5 W= 0.5
Assume a population of 100 shorthorns has 49 red (RR). 42 roan (RW). 9 white ( WW) Calculate the frequencies
49 Red (RR) = 98 red. 0 W
42 Roan (RW) = 42 R 42w
9 White (WW)= 0 r 18W
Add up red and white= 140 red 60 w
Divide both by 200
R= .7 W= .3
What do frequencies need to add up to to be right
1.0
How is the h-w law beneficial
Example
It is valuable when you can’t see the heterozygous genotype in your herd or flock
Exp: angus cattle
Genetic defects (PSS) (SLS)
This is a mixing of populations
Large changes in frequencies can be made quickly
Migration
This is a chemical change that alters DNA
It doesn’t occur often in a population
Mutations
What are the two types of selections and their definitions
Natural selection- occurs in wild populations
Artificial selection- controlled by humans
This is a loss or gain of traits due to changes in a gene pool that take place by chance.
Controlled by size of population (as population gets smaller then the increases)
Genetic drift
This is used as a way to compare animals across herds
Usually within a breed
National genetic evaluation programs
What are the three evaluation programs and what animals use them
EPDs = beef, swine, sheep
EBVs= sheep
PTAs = dairy, goats
What are some of the traits that the evaluation programs include
Reproduction Growth Carcass Milk production Disposition
What does EPD, EBV, PTA stand for
Expected progeny difference
Estimated breeding value
Predicted transmitting ability
This is the predicted difference between an individuals progeny and all contemporaries for the progeny
EPD
The genetic worth of an animal to a breed or flock
EBV
The expected difference in progeny averages it is equal to 1/2 the EBV
PTA
This is a measure of the confidence in the estimate and ranges from 0-1
As this approaches 1 we have more confidence in the estimate of genetic worth
Accuracy
This projects the genetic value of an animal as a parent based on past (ancestral) performance
It’s based on the progeny performance of a sire line
Expected progeny difference
What are the 3 most useful selection tools for herd improvement
Growth traits
Maternal traits
Carcass traits
EPDs are used to ___________ animals
EPDs are specific to a ___________
Compare
Breed
This is the key equation on making change in animal populations due to selection (the response animals will have to selection)
Genetic progress
What does Genetic Progress =
Heritability times selection differential
R= h squared * S
This is the portion that can be passed to offspring in the genetic progress formula
Or
The fraction of phenotypic differences between animals that is heritable from the parents
H squared
Heritabilityx
This is the difference between the selected individuals in the herd and the herd average
In GP formula
Selection differential
_____________ is the single most important parameter in the design of breeding programs
Heritability
What are some low heritability traits <0.2
Moderate heritability 0.2 to 0.4
High heritability >0.4
Low: reproductive traits (litter size/twinning)
Mod: growth traits (yearling weight/feed efficiency/pasture gain)
High: carcass traits (fat thickness/muscle size/ marbling)
What are limits to genetic progress?
Culling rates-the response of a population to selection will often level off at some point in time
You make the greatest progress when you have a high _______________ _______________
Selection differential
Genetic change per year =
Heritability times selection differential \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Generation interval (yrs)
This is the average age of the parents when the offspring is born
Generation interval
This is the choosing of animals to be parents of the next generation
Selection
This is what decides which parents are mated together
Mating systems
What are the two types of breedings and the examples of them
Inbreeding
- linebreeding
Outbreeding
- outcrossing
- grading up
- crossbreeding
- species crossing
What are the importance of mating system
- To maximize genetically superior animals within a herd or flock
- Preserve genetic material
- Utilize hybrid vigor- where offspring achieve more than the parents which = heterosis
This is mating animals that are closely related and what does it result in
Inbreeding
Results in increase of homozygosity of gene pairs
What does inbreeding do?
Increase homozygosity which = more AA and as genotypes
What are positives of inbreeding
- Crossing of inbred lines results in heterosis
- Can increase frequency of desirable traits
- Inbred animals with superior performance breed true
What are the negatives of inbreeding
- Generally causes lower production called inbreeding depression
- Reveals undesirable genes and could increase expression of lethal genes
What is an example of inbreeding in angus cattle?
Anthrogryposis multiplex
Or curly calf syndrome
This is a mild form of inbreeding
It concentrates on note or more ancestors in a pedigree (less of an increase in homozygosity)
Line breeding
What’s an example of line breeding in horses
Hyperkalemic periodic paralysis (HYPP)
This is mating of unrelated animals = increases heterozygosity (Aa)
Outbreeding
The mating of unrelated animals in the same breed
Outcrossing
Improving a stock of Animals for some productive function by consecutive matings with animals considered genetically superior
Mating of commercial female to pure breed sires
Grading up
Mating of animals in different breeds
They tend to be more vigorous, fertile, and healthy, grow faster than avg. of parental stock
Crossbreeding
An example of this is a mule
Species crosses
What is the advantage of crossbreeding
Heterosis
What does heterosis affect
Heritability
If heritability is low= high heterosis
In a terminal breeding system what happens to progeny
All progeny are sold
Which means all new females must be purchased or generated for herd
This is selection for specific alleles using markers such as linked DNA sequences
Exp include?
Marker assisted selection
Decrease mastitis in dairy industry
Selecting for or against double muscling
Increase carcass cut ability in hogs
Anatomy and physiology of repro
This is a branch of vet medicine concerned with vet obstetrics and with the diseases and physiology of animal reproductive systems
Theriogenology
What are the primary functions of reproductive organs
Production of gametes
Production of hormones(helps go into heat)
Fertilization
Development of embryo and fetus during pregnancy
Parturition
Reproduction is only possible as a result of physiological ________________
Compatibility
Species who are not compatible cannot reproduce
When is an animal first able to produce
Also known as the age at which an animal is first capable of producing fertile gametes
What is it for males and females
Puberty
M= appearance of spermatids
F= 1st ovulation
Age at puberty is influenced by an interaction between __________ and body composition (weight) and ________
Age and nutritio
Mostly age
The first ovulation is also known as the __________ ovulation because they usually don’t get breed during the first ovulation
Silent
What does the anatomy of the make repro tract consist of?
Tested (sperm production)
Duct system
Accessory sex glands
Penis
What are the major functions of the male repro tract
Production/maturation, stoargband transportation of Sperm
Production of the male sex hormone testosterone
This is an egg shaped organ which consists of seminiferous tubules and rete testis
What do the semi and rete do
Testicle
Semi- site of spermatogenesis(creation of sperm)
Rete- collecting ducts for the Newly formed spermatozoa
What is a sac which enclosed testes?
And what does it do
Scrotum
Radiates heat and contracts or relaxes to adjust temp
Temp for optimal spermatogenesis is below normal body temp
A ___________ results when one( ____________) or both (bilateral) testicles fail to descend into the ___________
Cryptorchid
Unilateral
Scrotum
Bilateral cryptorchids are ____________ but possess normal sexual activity and male appearance
Unilateral Only one dropped and can sometimes be ________
Sterile
Fertile
Sperm travel from rete testis to the head of the ________________ which is a long continuous tube with three regions called the head (caput), _________ (corpus), and tail (cauda).
Epididymis
Body
What is the
Caput
Corpus
Cauda
Head
Body
Tail
What does the epididymis do
Involved in maturation and storage
Then widens into larger tube known as vas deferens
What does the vas deferens do
Where does this become enlarged and site of join with urethra
Transports sperm to urethra
Ampulla which is a temp storage depot for sperm
This is the passage for both urinary and male repro system
It begins at opening of ________
And continuous with the ________
Urethra
Bladder
Penis
Where are male accessory sex glands located
What substances are added to nourish and simulate Sperm
Beginning of the urethra
Fructose for buffering capabilities
This provides substances which neutralize urine residue and adds volume and may stimulate sperm activity
Seminal vesicles
This is a donut shaped gland that surrounds the urethra near the opening of the bladder
Also provides nourishment and stimulates sperm activity
Prostate
These are walnut shaped glands that secret a substance that gels or thickens to coagulate semen they are very large in boars
Bulbourethral (cowpers gland)
This is a mixture of speed, fluids, and nutrients found in the ejaculate
Semen
This is the external copulatory organ. Consists of the glands penis, urethra, erectile tissue and prepuce
Varies in shape among species
Becomes engorged with blood during erection
Posterior section is S shaped (sigmoid flexure)
Penis
Males have the ability to produce an ___________ number of gametes (sperm)
Infinite
What do leydig cells produce
Testosterone
This is the general passageway to urinary and reproductive
The clitoris lies on the base
Vestubule
This is folds of skin that cover the opening to the vestibule
The exterior portion of female reproductive tract
Vulva
This is the sheath for acceptance of penis during copulation
Where semen is deposited in sheep and cattle during copulation
In horses and pigs some semen is deposited in the cervix and the uterine body
Vagina
Smooth muscle sphincter that is tightly closed except during estrus
Series of circular ridges in most species except mare
Passageway for sperm
Storage reservoir for sperm
Barrier between external and internal environment
Cervix
Site of implantation and fetal development
The wall consists of mucous membrane smooth muscle and outer peritonem
Humans don’t have uterine horn
Uterus
This is the catchers mit/surrounds portion of oviduct
Infundinulum
Where does fertilization occur
Another name for this is
Oviduct
Fallopian tubes
What produces estrogen and progesterone
It has follicles indifferent stages of development
Ovaries
What stimulates FSH and LH release
What is FSH
GnRH
FSH is the growth of follicles on the ovary
Without adequate FSH follicles undergo __________
This is when follicles regress and die and most follicles undergo this
Atresia (degeneration
What do developing follicles produce
What is estrogen responsible for
Elevated estrogen causes ________ surge from the anterior pituitary
Estrogen (the bigger they get the more the produce)
Reproductive behavior
LH
_________ causes breakdown of follicle wall and release of the ovum or also know as
LH
OVULATION
After ovulation, follicle becomes a ________________________
This thing produces progesterone
Corpus luteum
This is produced by uterus and cause ________________ which is the breakdown of the corpus liteum
The developing embryo produces factors that ________ production of PGF2a
Protoglandin F2a
Luteolysis
Suppress
______________ is released from posterior pituitary in response to nerve stimulus due to pressure on cervix
Oxytocin
What is the follicle called when it is really big
Antral follicle
Graafian
What are the 4 stages of folliculogenesis
Few follicles reach the size to produce enough estrogen to result in an _________ surge
Recruitment
Selection
Dominance
Atresia (for the follicles that donot ovulate)
LH
What is the luteal faze
Follicular faze
Development of corpus luteum
Follicular faze is: estrogen which results in heat
