Module 4.2.1 Biodiversity - Flashcards
What is a biosphere?
The part of the earth that contains all ecosystems
What is a biome?
A large region with the same plant life & climate
What is an ecosystem?
The community & it’s environment (interdependence)
What is a community?
Populations that live together in a habitat
What is a population?
The number of individuals living in the same habitat
What is a species?
A group of organisms that can reproduce to produce fertile offspring
What is biodiversity?
The variety of living organisms in the world or a particular habitat
Should there be low or high biodiversity & why?
High because it’s desirable
What are the 3 levels of biodiversity?
Genetic
Species
Habitat
What is habitat diversity?
The number of different habitats in an area
What is genetic diversity?
The variation of alleles within a species
What is species diversity?
The number of different species (species richness) & the abundance of each species (species eveness) in an area
Why is habitat diversity important?
The more range of different habitats in an area, the more diverse it is
Why is it important to have genetic diversity?
Individuals of the same species have the same genes but different alleles, if diversity is low the species is more susceptible to changes in the environment & could be wiped out by a single event/disease
What is an allele
Different version of a gene
What is polymorphism?
When a gene has more than 1 allele (e.g. hair/eye colour, blood type)
What is monomorphism?
When a gene has only one allele (most genes are monomorphic - ensures basic structure of a species is similar)
What is locus?
Where on the chromosome the alleles are (scientists look at different loci & see how many genes are polymorphic)
If a species has high genetic variety what will it have a greater proportion of?
Polymorphic gene loci
What is the calculation for proportion of polymorphic gene loci?
Proportion of polymorphic gene loci = Number of polymorphic gene loci/ total number of loci
What is species richness?
The higher the number of species = greater the species richness
What is species evenness?
The more similar the population size of each species = greater species evenness
What is random sampling?
Divide a field into a grid using a measuring tape & use a random number generator to select coordinates to take a sample
What is an advantage of using random sampling?
The data is unbiased
What are the disadvantages of using random sampling?
Doesn’t cover all areas equally & species with a low presence may be missed
What is systematic sampling?
Samples taken from fixed intervals across the habitat often along a line using quadrats
What is an advantage of using systematic sampling?
It’s useful when there’s a clear gradient in the environment
What is a disadvantage of using systematic sampling?
Only species that are on the line/belt are recorded - underestimate
What is stratified sampling?
Divide the habitats into areas which appear to be different & randomly sample each section separately
What is opportunistic sampling?
Researchers take samples based on prior knowledge/during the process of collecting data (may sample an area they know contains a particular species)
What is an advantage of using opportunistic sampling?
Easier & faster
What is a disadvantage of using opportunistic sampling?
The data is biased
How are plants sampled?
Using quadrats (frame/point) along a belt transect
What are some ways animals are sampled?
Pooter (small insects)
Sweep nets (insects in vegetation)
Pitfall traps (crawling invertebrates on the ground)
Tree beating (invertebrates in tress/shrubs)
Kick sampling (organisms in the water)
What is capture mark release recapture?
Researcher captures as many animals they can in a defined period of time, counts them & marks them (doesnt cause harm) & releases them to mix in the population. They’re captured again after a few weeks/days over the same time period & they count how many are marked
What is an advantage of capture mark release recapture
Doesn’t hurt the animals
What are the disadvantages of using capture mark release recapture?
There is assumptions that the animals didnt die/immigrate/migrate
What is the formula for population size?
Number in the 1st sample x number in 2nd sample / number in the 2nd sample previously marked
