biodiversity a level biology OCR

biodiversity

the number of different species in an area

the variety of organisms and habitats

habitat biodiversity

the number of different habitats found within an area

species richness

the number of different species present in a habitat

species evenness

a comparison of the number of individuals of each species living in a community

community

all the populations of living organisms in a particular habitat

genetic biodiversity

the variety of genes that make up a species

habitat

the place where a population lives

what do you use to measure light intensity

light meter

what is light measured in

lux

what is wind speed measured with

anemometer

what is wind speed measured in

m/s

what is relative humidity measured with

humidity sensor

what is humidity measured in

mg dm cubed

what causes the genetic biodiversity of a species to increase?

mutation- new allele are made

interbreeding between different populations- transfer of alleles (gene flow)

what causes the genetic biodiversity of a species to decrease?

Selective breeding

Captive breeding

Artificial cloning (asexual reproduction)

Natural selection (only advantageous allele passed down)

Genetic bottlenecks (only some survive to an event or change)

Founder effect (new colony made- isolated)

Genetic drift (due to random nature of alleles being passed down)

in situ conservation advantages

maintains the evolutionary adaptations: enables a species to adapt continually to changing environment

maintains interdependent relationships

cheaper

examples of active management techniques used in wildlife reserves

control grazing

control poaching

removal of invasive species

halting succession

restrict human access

reintroduction of species

problems associated with reintroducing species back into the wild

disease- resistance to disease may be lost in captive bred animals

genetic- the genetic makeup of captive bred animals may become very different to the wild animals, so they can no longer inter-breed

habitat- the habitat threshold may already be met, so it can no longer support new animals competing for space and food

behaviour- learned behaviours such as hunting for food may not be present in captive bred animals

explain the benefits of maintaining biodiversity to agriculture

Genetic variation/ higher number of alleles:

Used for selective breeding to create crops that can cope with climate change

Provide a habitat for pollinators

Source of a new medicine for livestock

how to make a biodiversity investigation more valid- REPRESENTATIVE

More transects in different parts of areas

Collect at different times of day and year

Use a butterfly net to capture individuals

Use a key to identify species