Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Genetics > Principles of Selection > Flashcards

Principles of Selection Flashcards

1
Q

is the art and science of the genetic improvement of farm animals.

A

Animal Breeding

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

choosing some animals as parents of the next generation of animals.

A

Selection

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

removal of inferior animals

A

Culling

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

What is the basis of animal breeding is ?

A

correct selection of breeding animals for mating

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

obtained as a regression of a phenotypic deviation

A

Estimation of Breeding Value

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

records deviated from a mean

A

Phenotypic Deviation

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

Breeding Value in the phenotypic deviations

A

Regression

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

is the proportion of the phenotypic variance that is due to genetic effects including additive, dominance and epistasis:

A

Heritability in the broad sense (H2)

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

is the proportion of the phenotypic variance that is due to additive genetic effects only.

A

Heritability in the Narrow Sense (h2)

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

What does the heritability in the narrow sense measure?

It measures the degree to which the offspring —-

If a trait has a large heritability, animals with high performance for the trait will produce offspring with —- ———

A

resemble their parents in performance for a trait.

High Performance

If a trait has a small heritability, performance records of parents reveal —— —— about the performance of their offspring

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

Traits with low heritability ranges from??

A

h2 < 0.20

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

Moderately heritable traits ranges from ??

A

h2 0.2 to 0.4

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

Highly heritable traits ranges from?

A

h2 > 0.40

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

Traits with low heritability (h2 < 0.20): charactersitics:

A

• reproductive traits

• longevity or productive live ( about 0.10)

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

Moderately heritable traits (h2 of 0.2 to 0.4): Characteristics: ll

A

• Milk yield, fat yield and protein yield (0.25-0.35)
• Birth weight
• Weaning weight
• Yearling weight

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

Highly heritable traits (h2> 0.4):

Characteristics:

A

• Carcass traits and traits related to skeletal dimensions like mature body weight

• Fat and protein% in milk.

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

animals are selected based on their ancestors, where the performance of these ancestors is known then a useful selection can often be made.

A

Pedigree Selection

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

the breeding value of each individual is assessed on the average performance of a random sample of its progeny, and animals are selected or culled based on this progeny performance

A

Progeny Testing

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

any animals unsatisfactorily for the character being selectedcan be culled before breeding is commenced.

A

Mass or Individual Selection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

selection based on theperformance of nearby relatives

A

Family Selection

21
Q

selection is made for one trait or character at a timeuntil it is improved, then for a second trait and so on.

A

Tandem Selection

22
Q

a method where minimum standards of performanceare established for each trait in the criteria. Anyanimal not satisfying the minimum standard for alltraits is culled.

A

Independent Culling Level

23
Q

Each character is given a score and scores for all characters being considered are added together. Those with the poorest total scores would be culled.

A

Selection Index

24
Q

breeding of two or more different breed of animal.

A

Crossbreeding

25
Q

means that breeding of animal with the same breed.

A

Purebreeding

26
Q

Mating between animals, which are more closely related to each other than the average relationship between all individuals in the population.

A

Inbreeding

27
Q

1st mating: A x B

1st generation: ½ A ½ B

2nd mating A x ½ A ½ B

2nd generation ¾ A ¼ B

A

Inbreeding

28
Q

Mild form of inbreeding. Mating of cousins, grandparent to grand offspring or half-brother to half sister.

A

Linebreeding

29
Q

Example: A is ♀; B & C is ♂
1st mating: A x B A x C
1st generation: ½ A ½ B ½ A ½ C
2nd mating ½ A ½ B x ½ A ½ C
2nd generation ½ A ¼ B ¼ C

A

Linebreeding

30
Q

Mating of animals of different families within the same breed that are not closely related. (For at least the first four to six generation.

A

Outcrossing

31
Q

is the mating of two animals from different breeds.

A

Crossbreeding

32
Q

The increased level of performance of the offspring as to compare to the average of the parental type is known as

A

Heterosis or Hybrid Vigor

33
Q

There is a ——– relationship between heterosis and heritability:

the traits that demonstrate the most hybrid vigor are those that show the ——- heritability.

A

Reciprocal

Lowest heritability

34
Q

Crossbreeding can be used to:

A

•Develop new breeds
•Upgrade local breeds

35
Q

Two different populations can be crossed with each other to produce an F1 generation which is used only for production purposes and not for breeding.

A

Single Two-Way Cross

36
Q

This system relies on the crossing of two breeds A and B to produce a female excelling in maternal performance in a particular environment and the use of a third breed to produced the ideal animal for the market product.

A

Three Way Cross

37
Q

Populations A and B are first crossedwith each other, and so are C and D to obtain the F1generation A x B and C x D. These are then crossedtogether to produce the double hybrids AB x CD. It isnecessary to maintain only relatively small number ofanimals of the lines A, B, C, and D.

A

Four way cross

38
Q

The F1 females are back crossed to oneof the parental populations. For example, A x B females are mated with A or B to produce an offspring AB x A or AB x B.

A

Backcross

39
Q

This method takes fulladvantage of heterosis in the F1 females and half ofthe potential heterosis in the offspring.

A

Backcross

40
Q

In which males of each of the two breeds involved are used alternately; this system hasthe advantages over the two-way cross, in that thecrossbreed females can be used for breeding.

A

Two-way rotational cross

41
Q

A x B —— AB
First mating : A x AB
Second mating: B x AB
Third mating: A x AB

A

Two-way rotational cross

42
Q

In which males of each of the three breeds are used in turn; cross bred females produced can be used for breeding.

A

Three-way rotational cross

43
Q

A x B x C ——- ABC
First mating : A x ABC
Second mating: B x ABC
Third mating: C x ABC

A

Three way rotational cross

44
Q

Selection for Quantitative Traits

A

Estimate merit (BV’s)
Determine accuracy of estimation
Predict response to selection

45
Q

Methods of Selection

A

Tandem Selection
Independent Culling Level
Selection Index

46
Q

Aids to Selection

A

Pedigree Selection
Progeny testing
Mass or Individual Selection
Family Selection

47
Q

Mating Systems

A

Cross breeding and Purebreeding

48
Q

Types of Crossbreeding

A

Inbreeding
Linebreeding
Outcrossing

49
Q

Methods of Crossbreedings

A

Single two way Crosses
Three way cross
Four way cross
Back cross
Two way rotational cross
Three way rotational cross

Genetics (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions