Unit 4 - Biodiversity Flashcards
Define abiotic factors
Non-living conditions in a habitat
Define belt transect
Two parallel lines are marked along the ground and samples are taken out of the area at specified points
Define biodiversity
The variety of living organisms present in an area
Define species
The smallest and most specific taxonomic group
Define Succession
The progressive replacement of one dominant type of species or community by another in an ecosystem, until a stable climax community is established.
Define intraspecific variation
The differences between organisms of the same species
Define interspecific varation
The difference between organisms of different species
Define monoculture
The cultivation of a single crop in a given area
Define normal distribution curve
The bell-shaped curve that results from plotting continuous variation data on a graph
Define correlation coefficient
Statistical test used to consider the relationship between two sets of data
Define keystone species
Species which are essential for maintaining biodiversity-they have a disproportionately large effect on their environment relative to their abundance
Define stratified sampling strategy
Populations are divided into strata based on a particular characteristic
A random sample is then taken from each of the strata proportional to its size
Define random sampling
Sampling where each individual in the population has an equal likelihood of selection
Define kingdom
The second biggest and broadest taxonomic group
Define autotrophic
Organisms that acquire nutrients by photosynthesis
Define genetic bottleneck
When large numbers of a population die prior to reproducing leading to reduced genetic biodiversity within the population
Define mutation
A change in the genetic material of an organism which may affect the phenotype of an organism
Define community
All populations of living organisms in a particular habitat
What is the founder effect?
When a few individuals of a species colonise a new area, their offspring initially experience a loss in genetic variation and rare alleles become much more common within the population
Define discontinuous variation
A characteristic that can only result in certain discrete values
Give an example of discontinuous variation
Blood type
Define continuous variation
A characteristic that can take any value within a range
Give an example of continuous variation
Height
Weight
Define divergent evolution
Species diverge over time into two different species, resulting in a new species becoming less like the original one
What is ex situ conversation?
Conservation methods out of the natural habitat
What is a seed bank?
A store of genetic material from plants in the form of seeds
Define gene flow
When alleles are transferred from one population to another by interbreeding
Define natural selection
The process by which organisms best suited to their environment survive and reproduce, passing on their characteristics to their offspring via their genes
Define ecosystem
All the interacting living organisms and non-living conditions in an area
Define habitat
The natural environment of an organism
Define population
The number of organisms of the same species living in a particular geographic area
What are the 3 types of biodiversity?
- habitat
- species
- genetic
What is habitat biodiversity?
The number of different habitats
What is species biodiversity?
The number of species and the abundance of each species in a particular location
What is genetic biodiversity?
The total number of genetic characteristics in the genetic make-up of a species
What is sampling?
The process of collecting data in a suitable way
Why is sampling important?
- means data is representative is as it can be
- makes data collection more manageable
What is random sampling?
Each individual in the population has an equal likelihood of selection
What is non-random sampling?
An alternative sampling method where the sample is not chosen at random
How could an area be randomly sampled?
- a grid could be laid out using two tape measures
- a random number generator is used to generate a grid reference
- a quadrat is placed at the grid reference
- a sample is collected
What are the 3 main non-random sampling techniques?
- opportunistic (pragmatic)
- stratified
- systematic
What is opportunistic sampling?
Sampling which uses organisms conveniently avaliable
What is stratified sampling?
- some populations can be divided into distinct groups
- a random sample is then taken from each of these groups proportional to its size
What is systematic sampling?
Samples are taken at regular intervals
What is a frame quadrat?
A frame quadrat consists of a square frame divided into a grid of equal sections
What is a point quadrat?
a point quadrat consists of a frame containing a horizontal bar, pins can be pushed down at set intervals to reach the ground. The plant which the pin touches is what is recorded
What is a line transect?
A line is marked along the ground between two points and samples are taken at specified points
What is a belt transect?
Two parallel lines are marked and samples are taken of the area between the two lines
What is an interrupted belt transect?
A transect is marked out and frame quadrats are placed at regular intervals along the transect