3.2 Plant and Animal Breeding Flashcards

1
Q

characteristics that breeders develop crops and animals with (4)

A
  • higher food yields
  • higher nutritional values
  • pest & disease resistance
  • the ability to thrive in particular environmental conditions
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2
Q

why are plant field trials carried out in a range of environments? (2)

A
  • to compare the performance or different cultivars or treatments
  • to evaluate GM crops
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3
Q

factors which have to be taken account of when designing field trials (3)

A
  • the selection of treatments
  • the number of replicates
  • the randomisation of treatments
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4
Q

why the selection of treatments has to be taken account of when designing field trials

A

to ensure valid comparisons

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5
Q

why the number of replicates has to be taken account of when designing field trials

A

to take account of variability within the sample

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6
Q

why the randomisation of treatments has to be taken account of when designing field trials

A

to eliminate bias when measuring treatment effects

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7
Q

inbreeding

A

when selected related plants or animals are bred together for several generations until the population breeds true to the desired type

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8
Q

in inbreeding, why does the breeding of related plants or animals together result in the population breeding true to the desired type?

A

due to the elimination of heterozygotes

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9
Q

negative effect of inbreeding

A

an increase in the frequency of individuals who are homozygous for recessive deleterious alleles

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10
Q

what will happen to individuals who are homozygous for recessive deleterious alleles, and what will this result in?

A

they will do less well at surviving to reproduce, which will result in inbreeding depression

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11
Q

in animals, what may happen when individuals from different breeds reproduce with eachother, and what can be done to continue to produce more of the result?

A
  • a new crossbred population will be produced, with potentially improved characteristics
  • the parent breeds can be maintained in order to produce more crossbred animals with the improved chracteristic
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12
Q

how are new alleles introduced to animal and plant lines?

A

by crossing a cultivar or breed with an individual with a different, desired genotype

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13
Q

in plants, how are F1 hybrids produced?

A

by crossing two different inbred lines

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14
Q

what is the result of crossing two different inbred plant lines?

A

F1 hybrids of a relatively uniform, heterozygous crop

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15
Q

F1 hybrids often have increased what? (2)

A

vigour and yield

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16
Q

why are F1 hybrids not usually bred together?

A

the F2 generation produced shows too much variation

17
Q

what does genome sequencing allow?

A

organisms with desirable genes can be identified and then used in breeding programmes

18
Q

how are GM plants created, and what is the difference between GM plants and natural plants?

A
  • single genes for desirable characteristics are inserted into the genomes of crop plants
  • GM plants have improved characteristics
19
Q

what kind of plants can be used in breeding programmes?

A

plants which have been genetically modified by recombinant DNA technology

20
Q

what genes may be inserted into plants used for plant breeding? (2)

A
  • Bt toxin gene
  • Glyphosphate resistance gene
21
Q

what is the Bt toxin gene for?

A

pest resistance

22
Q

what is the glyphosphate resistance gene for?

A

herbicide tolerance