Biodiversity Flashcards
Biodiversity
The diversity of the ecosystem, the number of different species and the genetic variation within the species
What are the problems with separating an area into small fragments
Less choice of mates, could lead to interbreeding. Interbreeding depression leads to decrease in genetic variation. It might be difficult to find food. More easily exposed to danger outside area
Advantages of zoos
Captive breeding and reintroduction. Education about the animals, can research the animals to find out about their behaviour. Can provide health care and fundraise for conservation projects in the wild
Species
A group of organisms with similar morphology and physiology which can breed together to produce fertile offspring
Niche
The role of an organism in an ecosystem
Ecosystem
A relatively self contained community of organisms and the environment in which they live and interact
Variation in ecosystem or habitat
Different organisms are adapted to different environments
Variation in the number of species and their relative abundance
Species richness is the number of species in an ecosystem. Species diversity takes into account species richness and a measure of the evenness of abundance of different species. Ecosystems with high species diversity tend to be more stable and able to resist change
Genetic variation within each species
Genetic diversity is the diversity of alleles within the genes in the genome of a single species. This can be assessed by finding out what proportion of genes have different alleles and how many alleles there are per gene. Genetic diversity provides populations with the ability to adapt to changes in biotic and abiotic factors
Sampling
It is difficult to identify every single organism in an ecosystem, instead we take samples from areas and use this to make an estimate of the total numbers in an area. Sampling can be used to find the distribution of organisms and their abundance
Quadrats
A quadrat is a large frame which marks off an area, you can identify the species in a quadrat and their abundance. Samples must be taken at random to avoid a bias, this can be done by marking off an area and using a random number generator to give you the coordinates on where to put down your quadrat. You need to decide a suitable size of quadrat and how many samples you will take
Species frequency
The chance of a particular organism being found within a quadrat. You record whether a species is present and then divide that by the number of quadrats and then times by 100 to get the percentage
Species density
How many individuals there are per unit area. The number of individuals you have counted is divided by the total area of all your quadrats.
Percentage cover
You decide approximately what percentage of the area inside the quadrat is occupied by each species, can be used for grass where you cant count each individual plant
Mark release recapture
A way of estimating the population size of mobile animals. As many individuals as possible are caught, they are marked in a way which will not affect their chance of survival. They are counted and left to mix with the rest of the population. When enough time for the mixing to take place has occured, another large sample is taken. The number of marked to unmarked individuals is counted. The proportion of marked to unmarked is then used to calculate the total number of the population. For example if in your second sample a tenth of the population were marked you would guess that you had originally captured a tenth of the population
Systematic sampling
Used to show how the population changes across an area, for example as altitude changes
Line transect
A line across one or more habitats. The organisms found at regular points along a line are noted. Transects are used to detect changes in community composition across a habitat
Belt transect
The abundance of organisms within quadrats placed at regular points along the line are noted
Simpsons index of biodiversity
Calculates a value indicating the level of biodiversity in the area, a value of 0 indicates low biodiversity and 1 represents a high level of biodiversity
Pearsons correlation coefficient
Can be used to determine whether there is a linear correlation, with normally distributed data
Spearmans rank correlation coefficient
Used when you are unsure about whether there is a correlation. Involves ranking the data recorded for each variable and assessing the difference between the ranks
Taxonomic hierarchy order
Domain, kingdom, phylum, class, order, family and species
Domain bacteria
Prokaryotic cells with no nucleus. DNA exists as circular chromosomes with no histone proteins associated with it. Has plasmids and 70s ribosomes. No membrane bound organelles. Cell wall is always present and made of peptidoglycan. Cell divides by binary fission not mitosis
Domain archaea
No membrane bound organelles or nucleus. Has plasmids and 70s ribosomes. Cell divides by binary fission and not mitosis. Cell wall present but does not contain peptidoglycon
Domain Eukarya
Cells have a nucleus and membrane bound organelle. DNA is arranged in linear chromosomes with histone proteins. Can be unicellular and multicellular. Has 80s ribosomes, chloroplasts, mitochondria and 70s ribosomes. Cell divides by mitosis. Many types of reproduction both asexual and sexual.
Kingdom Protoctis
Eukaryote, exists as single celled or a group of similar cells. Some are animal like and have no cell wall, they are known as protozoa. Others are plant like cells with a cellulose cell wall and chloroplast, they are known as algae
Kingdom Fungi
Eukaryote, they cant photosynthesise and have no chloroplasts. Heterotrophic nutrition they use organic compounds made by other organisms as their source of energy. Reproduce by means of spores. Either unicellular or made of long threads of hyphae. Cell walls made of chitin. Never have cilia or flagella.
Kingdom plantae
Multicellular eukaryotes that have cells which differentiate to form tissues and organs. Some cells have chloroplasts and can photosynthesise (autotrophic nutrition). Cells have a large permanent vacuole. Cell wall made of cellulose
Kingdom animalea
Multicellular eukaryotes with many different types of specialised cells that form tissues and organs. They don’t have chloroplasts and cant photosynthesise. Heterotrophic nutrition. Cell vacuole is small and temporary, no cell wall. Communication is via the nervous system. Cells sometimes have cilia or flagella
Viruses
Viruses are not in a classification system as they have none of the features we traditionally use in classification. Some consider them to not be a living organism as they infect cells and use their biochemical system to copy their nucleic acid and make proteins. The energy for this process is provided by the respiration of the host cell. We classify viruses based on the type of nucleic acid (DNA or RNA0 and whether its single or double stranded
Reasons why a plant may become endangered (2)
Habitat loss, human damage ie picking, climate change, soil erosion, use of herbicides, competition with other species and pollution
Why is it important to conserve species (3)
To maintain biodiversity and genetic diversity. To ensure the stability of the ecosystem. Humans may have to use them for resources such as medicine. Aesthetic reasons, moral reasons
