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WSC Science Department
Selective Breeding and Cloning –a comparison of the uses, advantages and
disadvantages of each
1.
Circle
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the statements that are true for selective breeding;
underline those that are true for cloning.
Some may apply to both with justification
Requires mitosis only, meiosis is not wanted
involves genes from two parents
is a relatively fast process for producing large numbers of animals and plants with desirable
characteristics
requires meiosis as well as mitosis
Often leads to the narrowing of the gene pool
Takes a long time(several generations) to produce breeds with the desirable phenotypes
Involves genes from one parent
Has been used to improve crops yields
Can be sped up by embryo transfer to use few female genetic parents
Can lead to unknowingly selecting for undesirable characteristics
Over thousands of years has developed numerous breeds from an ancestral type
Is a very precise method for raising organisms with desirable characteristics
Can be sped up by the use of artificial insemination to require few male parents
Causes a change in the genetic makeup of the population(breed)
Raising plants from cuttings or by grafting is a low technological version
Can be expensive and unpredictable
Always involves whole organisms
Tissue culture is a relatively high technological version
May involve whole organisms or selected genes
Offspring are have some genetic diversity
Leads to the rapid production of genetically superior animals
Too much use reduces genetic variation and susceptibility to changed conditions
Offspring are genetically identical
Can be used to produce transgenic animals and plants
Has produced most of the crop plants and animals raised for food or clothing
Can require the use of hormones eg in tissue culture or egg harvesting
Can be manipulated to rapidly produce numerous mutants (=genetically diversity)
Pure bred animals are homozygous for the characteristic traits
2. Now list the characteristics in the appropriate column
Selective breeding
Cloning
3. Use the above characteristics to write an answer to the question “What are the
advantages and disadvantages of using either selective breeding or cloning for the
production of human food and clothing?” You might begin by outlining the characteristics of
both-ie how they are similar and how they are different.
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Answers
Selective breeding
Over thousands of years has developed
numerous breeds from an ancestral type
Has produced most of the crop plants and
animals raised for food or clothing
Takes a long time(several generations) to
produce breeds with the desirable phenotypes
involves genes from two parents
Always involves whole organisms
requires meiosis as well as mitosis
Offspring are have some genetic diversity
Often leads to the narrowing of the gene pool
Pure bred animals are homozygous for the
characteristic traits
Can be sped up by the use of artificial
insemination to require few male parents
Can be sped up by embryo transfer to use few
female genetic parents
Has been used to improve crops yields
Causes a change in the genetic makeup of the
population(breed)
Can lead to unknowingly selecting for
undesirable characteristics
Cloning
Raising plants from cuttings or by grafting is a
low technological version
Is a very precise method for raising organisms
with desirable characteristics
Leads to the rapid production of genetically
superior animals
Involves genes from one parent
May involve whole organisms or selected genes
Requires mitosis only, meiosis is not wanted
Offspring are genetically identical
Often leads to the narrowing of the gene pool
Is a relatively fast process for producing large
numbers of animals and plants with desirable
characteristics
Can be expensive and unpredictable
Tissue culture is a relatively high technological
version
Can be used to produce transgenic animals and
plants (=have genes from different species)
Too much use reduces genetic variation and
susceptibility to changed conditions
Can require the use of hormones eg in tissue
culture or egg harvesting
Can require the use of hormones eg in tissue
culture or egg harvesting
Can be manipulated to rapidly produce
numerous mutants (=genetically diversity)