Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Animal Breeding > Exam 4 > Flashcards

Exam 4 Flashcards

(65 cards)

Start Studying
1
Q

What is inbreeding?

A

Mating of relatives more closely related than the average of the population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are some effects of inbreeding?

A

Increase homozygosity
Prepotency in inbreds
Expression of deleterious recessive alleles
Inbreeding depression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What increases homozygosity?

A

Number of common ancestors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a common ancestor?

A

An ancestor common to more than one individual

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is prepotency in inbreds?

A

Ability of an individual to produce progeny whose performance is the same as its own or is uniform

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does prepotency cause?

A

Fewer heterozygous loci

Cannot produce as many different gametes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Does inbreeding create genetic defects?

A

No, they must already be in the population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does inbreeding do for deleterious recessive alleles?

A

Increases the likelihood of them becoming homozygous and expressing themselves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is inbreeding depression?

A

Reverse hybrid vigor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does inbreeding depression mean for gene combination value?

A

It’s poor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is poor gene combination value a direct result of?

A

Increased homozygosity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is homozygosity and heterozygosity like with increased inbreeding?

A

Increased homozygosity, decreased heterozygosity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What traits does hybrid vigor work on first?

A

Fitness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is GCV and BV like with low heritability?

A

More GCV and less BV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is GCV and BV like with high heritability?

A

Less GCV and more BV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the inbreeding coefficient?

A

Measure of the level of inbreeding in an individual

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does it mean if an individual is 25% inbred?

A

It means that at a given locus in the individual, the probability that the two genes at the locus are identical by descent is 25%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Know the formula for inbreeding coefficient and Wright’s coefficient of relationship

A

Know the formula for inbreeding coefficient and Wright’s coefficient of relationship

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the 6 steps for calculating inbreeding and relationship coefficient using path method?

A
  1. Convert the pedigree to an arrow diagram in which each individual appears only once
  2. Locate common ancestors
  3. Locate inbred common ancestors and calculate the inbreeding
  4. Fill in the table
  5. Sum the last column
  6. Divide the sum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is line breeding?

A

Mating of individuals within a particular line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are 2 reasons to inbreed?

A

Increase uniformity

Create an opportunity for hybrid vigor–inbred line crossed with inbred line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is outbreeding/outcrossing?

A

Mating of unrelated individuals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does outbreeding do for homozygosity and heterozygosity?

A

Increase heterozygosity, decrease homozygosity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are 3 effects of outbreeding?

A

Masking deleterious alleles
Hybrid vigor or heterosis
Breed complementarity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What does hybrid vigor increase?
GCV | Fitness traits
26
What is heterosis/hybrid vigor?
An increase in the performance if hybrids over that of purebreds, most noticeably in traits like fertility and survivability
27
How do you measure hybrid vigor?
The difference between the average performance of crossbreds and the average performance of their parent lines of breeds
28
What is F1 hybrid vigor?
The amount of hybrid vigor attainable in first cross individuals Maximum hybrid vigor
29
Know equations 3, 4, 5, and 6 in notes
Know at equations 3, 4, 5, and 6 in notes
30
What are some hybrid vigor estimates?
Individual (direct component) Maternal Paternal
31
What is measuring heterosis levels doing?
Matching of unlike genes
32
What is retained hybrid vigor?
Hybrid vigor remaining in later generations of hybrids
33
What are general rules for retained hybrid vigor? (3)
Retained hybrid vigor is commonly expressed as a proportion of F1 vigor Hybrid vigor displayed by two-breed F1 crosses is halved in the corresponding F2s Mating of F2s to produce F3s will not diminish hybrid vigor–Hardy-Weinberg equilibrium
34
What are the 7 criteria for evaluating different crossbreeding systems?
``` Merit of component breeds Hybrid vigor Breed complementarity Consistency of performance Replacement considerations Simplicity Accuracy of genetic prediction ```
35
What is the amount of hybrid vigor in progeny in a two-breed terminal crossbreeding system?
100%
36
What is the amount of hybrid vigor in females in a three-breed terminal crossbreeding system?
100%
37
What is the amount of hybrid vigor in progeny in a three-breed terminal crossbreeding system?
100%
38
Look at the terminal crossbreeding chart
Look at the terminal crossbreeding chart
39
What is the amount of hybrid vigor in progeny in a two-breed rotational crossbreeding system after 7 generations?
67%
40
In a two-breed rotational crossbreeding system, what are the progeny females made of?
67% breed of sire | 33% breed of maternal grandsire
41
What is the amount of hybrid vigor in progeny in a three-breed rotational crossbreeding system after 7 generations?
86%
42
In a three-breed rotational crossbreeding system, what are the progeny females made of?
57% breed of sire 29% breed of maternal grandsire 14% remaining breed
43
Look at 2-breed and 3-breed rotational crosses
Look at 2-breed and 3-breed rotational crosses
44
What is the amount of hybrid vigor in progeny in a two-breed rotational and terminal crossbreeding system after 7 generations?
67% in rotation | 100% in terminal
45
What is the amount of hybrid vigor in progeny in a three-breed rotational and terminal crossbreeding system after 7 generations?
86% in rotation | 100% in terminal
46
Look at 2-breed and 3-breed rotational and terminal crosses
Look at 2-breed and 3-breed rotational and terminal crosses
47
What is the amount of hybrid vigor in progeny in a four-breed rotational crossbreeding system?
93%
48
What is a sire rotation?
Rotate sire every 4th year
49
How was selection done in the past?
Selection based on phenotypes | Selection based on genetic predictions
50
What are 4 examples of technology used in animal breeding?
MOET Cloning Sexed semen Split embryos
51
What is MOET?
Multiple ovulation and embryo transfer
52
What can MOET be used to do?
Increase numbers of offspring per female
53
What happens in cloning?
Somatic tissue is taken from a female and cells are grown, then transferred to recipients to get the exact copies of the cloned individual
54
What is accomplished with sexed semen?
Sex control
55
How is sex control done?
X sperm produces female, Y sperm produces males
56
How do split embryos work?
If there is a 16 cell embryo, 8 cells are put into one recipient and the other 8 are put into another
57
What is some DNA technology now available to producers? (3)
Fingerprinting Genetic markers Gene transfer
58
What is fingerprinting?
The occurrence of a fragment indicates it was received from one or both parents
59
What are genetic markers?
Positions on a chromosome that can be identified
60
How is selecting at the DNA level done? (3)
DNA fingerprinting Identification of genetic defects Marker-assisted selection
61
What does marker assisted selection use?
Genetic markers to select animals for quantitative traits
62
What should genetic markers be used in association with?
Measures of genetic merit to make the most genetic change
63
Why do genetic markers not change very much in performance?
There are associated with one gene
64
What is fingerprinting useful for?
Parental identification in multi-sire herds
65
What should marker assisted selection be used with?
Quantitative measures

Animal Breeding (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions