Artificial selecton

Question 1

What does it mean that populations are polymorphic?

Answer 1

display more than one distinct phenotype for most characteristics

Question 2

What is the wild type allele?

Answer 2

• the allele coding for the most common, or normal, characteristic

Question 3

What are mutants

Answer 3

• other forms of that allel, resulting from mutations, are called mutants

Question 4

What is artificial slection?

Answer 4

• selective breeding
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Question 5

How is artificial selection similar to natural selection?

Answer 5

• fundamentally the same as natural selection except for the nature of the selection pressure applied
• instead of changes in the environment leading to survival of the fittest, it is the selection for breeeding of plants or animals with desireable characteristics by farmers or breeders

Question 6

What is inbreeding?

Answer 6

• organisms with desireable characteristics are bred
• offspring with the best examples of desired traits are then bred
• inbreeding is the breeding of closely related individuals
• this changes the allele frequency and eventually speciation

Question 7

What is the problem with inbreeding?

Answer 7

• limiting the gene pool and so decreasing genetic diversity reduces the chances of a population of inbred organisms evolving and adapting to changes in their environment
• many disorder are caused by recessive alleles
  
  • organisms that are closely related and genetically similar are more likely to have recessive alleles
  • inbreeding therefore increases the chance of being homozygous for these recessive traits
  • reduces the ability of the organism to survive and reproduce

Question 8

What are seed banks?

Answer 8

keep samples of seeds from both wild and domestic vaireties

important genetic resource

Question 9

WHat are gene banks?

Answer 9

• gene banks store biological samples
• other than seed
• such as sperm or eggs
• usually frozen

Question 10

How are alleles from gene banks used?

Answer 10

• due to problem caused by inbreeding, alleles from gene banks are used to increase genetic diversity in a process called outbreeding
• breeding unrelated or distantly related varities is also a form of outbreeding
• this reduces the occurence of homozygous recessives and increases the potential to adapt to environmental change