genetics Flashcards
1
Q
behavior is influenced by what two factors?
A
- hereditary
- environmental
2
Q
act in _____ to form behavioral characteristics and patterns
A
concert
3
Q
Highly heritable traits are readily altered through ___________
A
selective breeding
4
Q
what gives the phenotype?
A
genes and environment
5
Q
define heritability
A
ratio between genotypic and phenotypic variance, genotypic variance/phenotypic variance
6
Q
which of the following situations is heritable based on genes? number of legs in dogs or length of dog legs
A
length of dog legs
7
Q
If a trait is highly heritable then the trait in _______ is largely due to genetics
A
phenotype
8
Q
do low heritability have more to do with genes or the environmental influences and why?
A
environmental influences because progress through selection will be small
9
Q
define low heritability
A
planned changes in environmental elements if it is desired to alter them
10
Q
Hereditary influences are evaluated through _______________________
A
studies in behavioral genetics
11
Q
hereditary influences are a major consideration in understanding _________ and ___________
A
evolution and domestication
12
Q
how is evolution and genetics important in genetic traits?
A
so the animal can adapt to the environment we provide
13
Q
describe the scientific field of behavioral genetics
A
the component of a given behavior that is controlled by inheritance and approaches to altering behavior through selective breeding
14
Q
what are the relative influences on the desired or undesired behavior in order to change animal behavior?
A
environment and genetics
15
Q
behavior is controlled by which two primary systems?
A
central nervous system and endocrine
16
Q
Systems develop and become active under control of?
A
genes
17
Q
a given behavioral characteristic represents a ______ array of _____ and _______ control mechanisms
A
complex
neural
endocrine
18
Q
a given behavioral characteristic most likely involves what kind of genes?
A
polygenes
19
Q
name some behavioral traits that has been observed due to a single gene effect
A
- nest cleaning in bees
- aggression toward strangers in Shiba inu
20
Q
aggression toward strangers in Shiba inu is due to what and how does it work?
A
- polymorphism of neuronal/epithelial high-affinity glutamate transporter
- glutamate hangs around and acts as a neurotoxicity, glutamate builds up in the cell which can lead to aggressive behavior
21
Q
define scientific term behavior and how it is accomplished
A
◼ result of transmissions through neural and endocrine mechanisms, and the response functions
◼ accomplished by specific target tissues responsible for the mechanics of executing the action
22
Q
Craig and Muir studied selection for low levels of feather and cannibalistic pecking, what was their result?
A
they found to be successful with selective mating
23
Q
we can reduce low levels of feathers and cannibalistic pecking to eliminate the need for ?
A
beak trimming
24
Q
why do we want to eliminate the need for beak trimming?
A
it is a painful procedure that results in sensitivity of remaining tissue for extended period
25
Craig and Muir's study of selective mating selected stock resulted in what three characteristics?
1. lower death loss
2. higher egg production
3. improved feathering
26
what are some traits that have responded to selection?
◼ Temperament in dairy cattle
◼ Mating and maternal behavior in beef cattle
◼ Temperament and trainability in horses
◼ Trainability, docility, hunting, working characteristics in dogs
◼ Broodiness and cage adaptability in chickens
27
utility of heritability estimates is in predicting the response to _________ ?
artificial selection
28
behavioral characteristics are determined by what? and what is the formula?
heredity and environment
| P = G + E
29
what are the three major categories of factors which determine the behavioral phenotype of an individual?
◼ Physiology = Internal environment
◼ External environment
◼ Heredity
30
define sexual effects
Sexual reproduction occurs in life forms that can adapt to wide variety of environments (that fluctuate)
31
what is the primary biological function of sex & sexual reproduction?
◼ to allow fresh samples to be drawn from populations gene pool
◼ maintain genetic variability
32
sex is determined by?
sex chromosomes
33
what are the chromosome combination for males and females?
females: XX
males: XY
34
what are the chromosome combinations for bird females and males?
female: ZW
male: ZZ
35
sex-linked genes can influence what?
behavioral traits
36
what is an example of a sex linked effect
white leghorns = nonbroody
| cornish = broody
37
what happens when selecting for desirable traits?
you can inadvertently select for undesirable traits that may not show for several generations
38
according to the breed crossing study, which had the greater effect on incidence on broodiness, sire or dam?
sire
| **cross of parental stock / phenotype of F1 hens**
39
which breed of sire contributed to broodiness? nonbroody?
cornish
| white leghorns
40
which chromosome has most of the genes influencing broodiness that results can be explained?
Z
41
what is the nonbroody allele and from what breed?
Z-
| white leghorn
42
what is the broody allele and from what breed?
Z+
| cornish
43
what was the result of the reciprocal crosses of a WL x bantam?
there was no significant difference for incubation behavior, environment plays a big role and there are at least 2 dominant autosomal genes involved
◼ One causing, one inhibiting the behavior
44
When the progeny of reciprocal crosses between parental stock differ in a behavioral trait are compared
Possibility that differences between F1 progeny of the crosses may be caused by differences in maternal environment (before or after birth)
45
why would use a reciprocal cross for a basenji and a cocker spaniel?
Compare F1 progeny for behavioral traits
◼ Cockers are friendly, nonaggressive
◼ Basenjis are aggressive & wary
46
what was the result of the basenji x cocker spaniel study?
◼ F1’s behaved same as breed of dam
| ◼ F2 pups showed same behavior
47
how did most behaviors show of the basenji x cocker spaniel and what were exceptions?
- no difference in most behaviors
◼ Attraction behavior
◼ Scored as number of times 13-15 wk old pups approached/followed experimenter
48
define attraction behavior
how likely a puppy is to follow experimenter
49
Approaching & following humans learned from mother
| ◼ Persisted from weaning (_ wk) to ~__ wk
8-15
50
Continuation of behavior w/ F2 pups indicates ____ inheritance by way of _____ influence
social
| maternal
51
what were the three main takeaways from the chicken and dog research?
◼ Sex-linked effects
◼ Autosomal gene effects
◼ Environment- (maternal influence) effects
52
define inbreeding
◼ Mating individuals that are more genetically related than average of population
- Relatives
53
increased homozygosity =
decreased heterozygosity
54
inbreeding depression =
loss of hybrid vigor
55
list two intensive inbreeding pairing
◼ Mating full sibs
| ◼ Sire/daughter
56
what happens when there are successive generations of full sib matings ?
◼ Population becomes subdivided into many small sub-populations (lines)
◼ Different lines would drift apart genetically
◼ Individuals within lines would become more alike
57
list the four things that happen when there is close inbreeding
1. Population divided into subpopulations
2. Lines become very different from one another
3. Uniformity increases within lines
4. General loss of vigor
58
list inbreeding effects
- Loss of heterozygosity
- More detrimental alleles expressed
- Loss of overdominance
59
out of the 8 original lines of the poland china swine, how many survived?
3 but only 2 with sufficient numbers for comparison
60
what happened when there was extreme loss of vigor in poland china swine
◼ Delayed maturity
◼ Small litters
◼ ↓ disease resistance
◼ Minimal boar libido
61
compare the two lines of poland china swine
```
- M
◼ Friendly
◼ Too mild tempered
◼ Indifferent to squeals of piglets -crushed
- N
◼ “Wild”
◼ Savage defense of piglets
◼ Trampled young
```
62
what is the purpose of "mild" inbreeding
“fix” desirable gene combinations in a line
63
what are examples of using mild inbreeding and what effects come from each
- guide dogs but loss of reproductive fitness
| - produced lines of german shepherds with greater uniformity in appearance and trainability , improved temperament
64
define outbreeding
breeding animals that are less genetically related
◼ Heterosis
◼ Crossing breeds w/in species
◼ Crossing lines w/in breed
65
list what heterosis increases
◼ Repro
◼ Fitness
◼ Survivability
◼ Growth rate
66
behavior traits = _____ traits
fitness
67
example breeds of guide dogs and how we use heterosis with them
◼ Crossing Breeds or lines w/in breed
| ◼ Labs/Golden Retriever
68
what does "more uniform" mean?
◼ More Aa vs. AA or aa
| more heterozygous genotypes, not increasing homozygous- increasing heterozygous
69
which are better buffered: heterozygotes or inbred? what does buffered mean?
heterozygotes
| Not as affected by environmental stressors, better suited to survive in the environment
70
heritability indicates how effective ________ should be
selection
71
- if heritability is high, selection will be successful, that trait is influenced by ________
- if heritability is low, expression is more dependent upon _________
- genetics
| - environment
72
what does h2 = .25 in quarter horses indicate?
◼ Indicates that 25% of superiority (or inferiority) is associated w/ genetics
◼ Other 75% is associated with environment
73
if the horse's average running speed is 40 mph and heritability=.25 and the parent's speed is 44, what's the selection differential? whats the EBV? expected progeny difference?
* selection differential: 44-40=4mph
* EBV: .25(4)=1mph
* expected progeny difference: 40+1=41 mph
74
define selection differential and how to calculate it
tells what parents are relative to population
| average of parents - average of population = selection differential
75
how to calculate EBV
selection differential x h2
76
what is expected progeny difference and how to calculate it
* predictions of the genetic transmitting ability of a parent to its offspring
* take EBV and add to average of population
77
list heritable behavior traits
```
◼ Feed consumption in broilers
◼ Temperament in dairy cattle
◼ Running speed in horses
◼ Avoidance learning in swine
◼ Social dominance in chickens
```
78
what happens with many generations of selection
◼ Produce large phenotypic differences
| ◼ Faster with high h2 estimates
79
why would you need a large animal data pool
◼ Controlled environment
| ◼ Estimates can change over time
80
describe the selection study learning ability in rats
- what was the goal
- what strains of rats were used
- how many studies were conducted
- what kind of selection
- what was used to test the performance of the rats
- outcome and results
- Can we select and make progress between two different rats
- Dull rat vs. bright rat strains
- 5
- bidirectional
- mazes
- bright rats were selected for were good at a specific type of mazes,
◼ Clear differences ◼ 4-7 generations of selection ◼ 2 distinct populations
81
what was selected for in the rat study
- Not selecting for overall intelligence or ability, selected for a certain environment, certain task
◼ Selection was effective in changing ability to solve particular type of problem
◼ Changes in learning ability
◼ Specific for type of mazes used
◼ No carry over to learn how to negotiate different types of mazes
82
describe dogs and learning ability, what have we selected them for?
We haven’t selected dogs for overall intelligence but for specific traits and behaviors
83
what do we select for in mating frequency of males?
High libido & related behaviors desirable
84
Long term selection study in cockerels
- why cockerels?
- how many generations of selection?
- why high line males?
- what was the control
- takeaway?
- use chickens so easier to manage and can use a lot more
- 8
- High line males= line of birds that had high mating ability (4x as many matings). Low lines= cockerels weren’t efficient at mating ability.
- Unselected randomly bred population = controls
- we can select males for mating ability
85
explain how genetic variation is not exhausted by natural selection
didn’t have those mating cockerels in nature, because they'd be so focused on mating then they’re more subjected to predation instead of looking for food, etc., just bc a male wants to mate a lot doesn’t mean his production is efficient, his fertility could be detrimental if mating too much, concentration of sperm reduced.
86
define correlated response and provide an example
Strong selection pressure applied to trait
◼ Change other traits as well
◼ Long term selection for speed in TB’s
◼ Lean body, long legs, flighty behavior
87
Form & ______ go together
function
88
why would there be extreme selection pressure for turkey breeder?
Width of breast & rapid growth
89
true/false: turkeys are good breeder
false
90
what must take place in order for turkeys to be able to reproduce?
AI
91
Why do we get correlated responses?
- Gene linkage- two genes, two alleles are coupled. Sit next to each other on chromosome, mixing of alleles, neighbors go together through meiosis and end up together in gametes
- Pleiotropy- have an allele that affects expression of more than one trait. Selecting for allele could be good but cold also not be good. A desirable trait could be also detrimental
92
how does Genotype-Environment Interactions occur?
Occurs when strains or breeds perform differently (relative to each other) in different environments
- Particular strain, animals react differently depending on genetic makeup in environment
93
what are the 3 distinct situations involving pairs of genetic stock as compared in pairs of environments
Example 1
◼ No interaction
◼ Both stocks do better in environment A vs. B
Example 2
◼ Genotype-environment interaction
◼ Stock W is very superior to Z in environment C
◼ Stock W is slightly better than Z in environment D
Example 3
◼ Extreme case of interaction
◼ Strain U is superior in environment E
◼ Strain V is superior in environment F
94
Cook & Siegal
◼ Compared 3 genetic stocks for mating ability of
cockerels
◼ Sample halves of each stock reared in all male or bisexual flocks
3 lines had same ranks when tested, regardless of method of rearing
- what was the results?
Line selected for high mating frequency had highest % of males mating once or more (eight 10 minute trials)
Low mating frequency line had lowest %, regardless of how they were reared
Genotype-environment interaction present
◼ Greater difference present between high & low lines when cockerels of those 2 stocks had been reared in all-male flocks vs. when samples of both lines were reared with females
- [ ] Reared in all male vs bisexual: high mating line high mating in al male flock, unselected controls and low mating frequency flocks increased when reared bisexually
- [ ] High frequency may have dropped off in bisexual rearing could just be anomaly
- [ ] Increase in low frequency line: had more environmental influence where they can have more interest in mating when reared bisexually
