Genetics and Diversity - Diversity Flashcards
What is a genetic bottleneck?
an event that causes a sudden reduction of a population
What effects do genetic bottlenecks have on diversity?
decreases diversity as there are less allele combinations in the gene pool
What is a polygene?
a characteristic that is affected by more than one gene
What are the 2 types of selection?
directional selection
stabilising selection
What is stabilising selection?
selection favours average individuals and preserves characteristics of the population
What is directional selection?
selection that favours individuals that lie outside the mean
this changes the characteristics of the population
What are the 3 types of adaptations that can be caused due to natural selection?
anatomical
physiological
behavioural
What is an anatomical adaptation?
changes to the physical features of an organism
What is a physiological adaptation?
metabolic changes in an organism
What is a behavioural adaptation?
changes to the behaviour of an organism
What is phylogeny?
the evolutionary relationship between organisms
What are courtship behaviours?
behaviours that help attract mates
What does courtship behaviours allow organisms to do?
recognise members of their own species
identify a mate that is capable of breeding
form a pair bond
synchronise mating
become able to breed
What is a phylogenic classification?
arranging organisms into taxons based on their evolutionary origins and relationships
What is a taxon?
a group within phylogenic classification
What are the phylogenic classification taxons?
Domain
Kingdom
Phylus
Class
Order
Family
Genus
Species
How are names of organisms written using the binomial system?
genus name, then species name
species name has a capital letter
if species unknown, can be written as ‘sp’
written in italics or underlined
What are the types of biodiversity?
species diversity
ecosystem diversity
genetic diversity
What is species diversity?
the variety of species within a community
What is ecosystem diversity?
the range of different habitats in a specified area
What is genetic diversity?
variety of genes possessed by individuals within a species
How is species diversity reduced?
new predators/pathogens/competition
intensive farming
How can intensive farming reduce species diversity?
removal of woodland and hedges
use of pesticides
monocultures
overgrazing land
draining wetlands
absence of crop rotation
How can intensive farming be improved to protect species diversity?
use hedges not fences and plant young trees
uses natural pesticides (eg nets around crops)
rotate animals and crops
How can genetic diversity be compared?
compare:
observable characteristics
DNA base sequences
mRNA base sequences
amino acid sequences of proteins
Why might a sample not be representative of the population?
sampling bias
chance
What is sample bias?
when an investigator, either delibaretly or unconciously, doesn’t take a representative sample
How can sampling bias be avoided?
by using a large sample size and data analysis
What does a normal distribution show?
continuous variation
