Last Quiz Flashcards by Abby Davis

This is a mathematical model on the genotypic and allelic frequencies of a population

Hardy Weinberg law

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What is the formula for the h-w law

P2 (squared) + 2pq+ q2 (squared)

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Population is large

Randomly mating

Not affected by mutations, migration, or natural selection

Hardy Weinberg equilibrium

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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

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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

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What do frequencies need to add up to to be right

1.0

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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)

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This is a mixing of populations

Large changes in frequencies can be made quickly

Migration

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This is a chemical change that alters DNA

It doesn’t occur often in a population

Mutations

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What are the two types of selections and their definitions

Natural selection- occurs in wild populations

Artificial selection- controlled by humans

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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

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This is used as a way to compare animals across herds

Usually within a breed

National genetic evaluation programs

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What are the three evaluation programs and what animals use them

EPDs = beef, swine, sheep

EBVs= sheep

PTAs = dairy, goats

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What are some of the traits that the evaluation programs include

Reproduction 
Growth
Carcass
Milk production
Disposition

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What does EPD, EBV, PTA stand for

Expected progeny difference

Estimated breeding value

Predicted transmitting ability

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This is the predicted difference between an individuals progeny and all contemporaries for the progeny

EPD

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The genetic worth of an animal to a breed or flock

EBV

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The expected difference in progeny averages it is equal to 1/2 the EBV

PTA

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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

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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

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What are the 3 most useful selection tools for herd improvement

Growth traits

Maternal traits

Carcass traits

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EPDs are used to ___________ animals

EPDs are specific to a ___________

Compare

Breed

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This is the key equation on making change in animal populations due to selection (the response animals will have to selection)

Genetic progress

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What does Genetic Progress =

Heritability times selection differential

R= h squared * S

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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

1. To maximize genetically superior animals within a herd or flock 2. Preserve genetic material 3. 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

1. Crossing of inbred lines results in heterosis 2. Can increase frequency of desirable traits 3. Inbred animals with superior performance breed true

What are the negatives of inbreeding

1. Generally causes lower production called inbreeding depression 2. 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