Genetic Biodiversity

Question 1

Genetic diversity

Answer 1

Genetic variation that exists within a species

Question 2

Why is diversity important in species ?

Answer 2

• creates a layer gene pool
• this helps with the population adapt, survive changes in the environment

Question 3

How can genetic diversity be assessed ?

Answer 3

• the proportion of polymorphic gene loci = the number of loci that have 2 or more alleles
• proportion of the population that is heterozygous for any specific gene locus
• allele richness = the number of different alleles that exists for specific genes

Question 4

Genetic polymorphism

Answer 4

When there are two or more alleles present at a single loci

• rarest allele will have a frequency greater than 1% or greater than 5%

Question 5

Monomorphic locus

Answer 5

One that does not have multiple alleles

Question 6

Polymorphic locus

Answer 6

One that has multiple alleles

• most common allele must have a frequency less than 95% or 99%
• if the most common allele has a frequency greater than 99% them the other alleles are extremely rare and likely to disappear

Question 7

How do scientists assess the genetic diversity of a species population ?

Answer 7

• identify a number of gene loci to investigate
• identify how many of these gene loci are polymorphic
• number of polymorphic gene loci is then divides by the total number of loci being investigated

Question 8

Proportion of polymorphic gene loci equation

Answer 8

Number of polymorphic gene loci / total number of loci investigated

Question 9

Limitations of P

Answer 9

proportion of polymorphic genetic loci does not illustrate the allele richness of a breed or species

Question 10

What is a alternative method to assess genetic diversity ?

Answer 10

• Comparing the amino acid sequences of proteins
• comparing DNA sequences

Question 11

Locus

Answer 11

Specific linear position of a particular gene on a certain chromosome

Question 12

Factors that affect genetic biodiversity

Answer 12

• mutations in the DNA of an organism creating a new allele
• interbreeding between different populations

Question 13

Gene flow

Answer 13

When an individual migrates from one population and breeds with a member of another population alleles are transferred between the two populations

Question 14

In order for genetic biodiversity to decrease the number of possible alleles in a population must also decrease this can occur through:

Answer 14

• selective breeding
• captive breeding programs in zoos and conservation centres where only a small number of captive individuals of a species are available for breeding
• rare breeds where selective breeding has been used historically to produce a breed of domestic animal or plant with characteristics which then become less popular so the numbers of the breed fall catastrophically
• artificial cloning
• natural selection = species will evolve to contain primary the alleles which code for advantageous characteristics
• genetic bottlenecks = where few individuals within a population survive an event or change thus reducing the gene pool
• genetic drift = due to random nature of alleles being passed on from parents to their offspring
• founder effect = where a small number of individuals create a new colony geographically isolated from the original