Section 4 - Genetic information, variation and relationships between organisms: 10. Biodiversity Flashcards
What is a species
A group of organisms capable of breeding to produce fertile off-spring
What is the binomial system for naming species
- Generic name (first) = Genus
- Specific name (second) = Species
What is classification
The organisation of organisms into groups
What is taxonomy
The theory and practice of biological classification, studying taxons and their hierarchal order
What are the two type of classification
- Artificial classification
- Phylogenetic classification
What is Artificial classification
Grouping organisms based on their features and analogue characteristics, useful at the time (No evolutionary links)
What is Phylogenetic classification
Hierarchal Grouping based on evolutionary links and relationships, where groups share features derived from common ancestors
What is the order of the Linnaean taxonomy system
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
What is a taxon
A group withing taxonomic classification
What is Phylogeny
The evolutionary relationships between organisms
What are the 3 domains
- Bacteria
- Archaea
- Eukarya
What are bacteria
Group of single celled prokaryotes
What are the common features of Bacteria
- No membrane bound organelles
- Unicellular, though can form clusters
- 70s Ribosomes (smaller than Eukaryotes)
- Cell walls made of murein
- Single loop of DNA with no histones
What are archaea
Group of single celled prokaryotes (originally classified as bacteria)
What are the common features of Archaea
- Genes and protein synthesis similar to eukaryotes
- Membranes contain fatty acid chains joined to glycerol by ether linkages
- No murein in cell walls
- More complex RNA polymerase than bacteria
What are Eukarya
Group of organisms made of one or more eukaryotic cells
What are the common features of Eukarya
- Membrane bound organelles
- Membranes contain fatty acids joined to glycerol by ester linkages
- Not all have cell walls, but those with don’t contain murein
- 80s Ribosomes (larger than bacteria and archaea
What 4 kingdoms do Eukarya divide into
- Protoctista
- Fungi
- Plantae
- Animalia
What is the role of courtship behaviour
- Allows individuals to recognise members of the same species (same across species, with a typical chain of action)
- Allows individuals to see if a mate is capable of breeding
- Forms pair bonds
- Synchronises mating
- Allows individuals to become able to breed
What is biodiversity
A measure of the number and type of organisms in an ecosystem
What is species diversity
A measure of how many species are present in an area, and how many individuals of each species there are
(measured with species diversity index)
What is genetic diversity
A measure of the total number of alleles in a population, altered by natural selection and linked to allele frequency/genetic drift
What is genetic drift
A change in the gene pool of a population that occurs purely by chance (not due to advantageous characteristics)
What is the bottle neck effect
Sever genetic drift when the population size is drastically reduced, resulting in less genetic diversity (eg. natural disaster/extinction event)
What is the founder effect
Loss of genetic variation when a new population is established from a larger one (smaller pop. size)
What is habitat diversity
A measure of how many different habitats are present in an area
What is a habitat
The range of physical, biological and environmental factors in which a species can survive (i.e. where a population of a species lives)
What is Ecosystem diversity
The variety of different habitats, communities and ecological processes within an area
Links to the interactions between biotic and abiotic factors, including the movement of energy, nutrients and species
What is Endemism
Species unique to a particular area/habitat (native) that is geographically discrete
What is Cosmopolitan distribution
When a species is vastly distributed across many regions/most of the world
(opposite of endemism)
What are biodiversity hotspots
Regions with a high level of biodiversity, but is threatened with destruction
What is species richness
The number of different types of species in a particular area
(doesn’t account for the number of individuals in each species)
What is species evenness
A comparison of the size of populations (No. of individuals) of different species in an area
Why is biodiversity important
- Ecosystems rely on the interdependence of organisms to maintain stability
- Relied upon for the survival of all organisms (Humans!)
- Pollination for food production
- Trees/plants slow water to allow for absorption
- Agriculture relies on insects/native species
- Medicines rely on natural resources
etc…
What is Simpson’s diversity index
D = N(N-1) / Σn(n-1)
What information is needed to calculate Simpson’s diversity index
N = Total number of organisms of all species
n = Total number of organisms of each individual species
What are the human activities that impact Biodiversity
- Removal of Hedgerows
- Creating monocultures
- Filling in ponds, marshes and wetlands
- Overgrazing of land
- Pesticide/inorganic fertiliser use
- Effluent escaping from silage stores (into local water)
- Absence of crop rotation (lack of intercropping)
Why are Hedgerows removed by humans
Removed to increase land area for agricutre and farming
Why are natural hedge rows important for Biodiversity
- Provide resources for animals, birds and insects, such as food and shelter
- Dead wood/leaf litter provides habitats for invertebrates, and recycles nutrients to the soil
- Contain many native species/increase species diversity
- Act as a physical barrier to water, increasing absorption into the soil
How can the impact of removing hedgerows be reduced
- Leave native hedge rows to protect the endemic species
- Plant hedge rows as boarders to increase biodiversity in the area
What is a monoculture
The mass production of one type of food, as it is easier to grow, maintain and harvest
How do monocultures impact biodiversity
- Reduction in biodiversity, due to only one species being grown
- Impacts insects and local wildlife that relies on the interdependence within the ecosystem
- Less variety of nutrients being recycled to the soil for fertile land
- The Large farms of monocultures increase the CO2 emissions, due to production of fertilisers, machinery, etc.
How can the impact of monocultures be reduced
- Grow a polyculture system, with a variety of species, rather than just one (intercropping)
- Rotate crops, so a different species is grown after a period of time
Why are pond, marshes and wetlands filled in by humans
Increase land area for agriculture, farming and urban development
Why are ponds, marshes and wetlands important for biodiversity
- Support fresh water wildlife
- Wetlands store carbon, and soak in water to slow the flow (prevent floods/water level rise downstream)
- Marshlands can filter out pollutants
- Act as breeding grounds
- provide resources for the survival of many species
How can the impact of filling ponds, marches and wetlands be reduced
- Leave/protect current wetland ecosystems to reduce the loss of biodiversity
What is overgrazing
When plants are exposed to intensive grazing over a long period of time either due to poorly managed agriculture (eg. game reserves), or livestock for farming
What is the impact of overgrazing on biodiversity
- Prevents the regeneration of woodlands and other ecosystems, damaging the biodiversity of these areas
- Leads to weakened soil integrity, leading to nutrient depletion which causes poor crop growth
- Decrease plant leaf surface area, reducing photosynthesis, so less energy (therefore grow poor root system)
How can the impacts of overgrazing be reduced
- Grow plants (especially endangered) in an area with less animals/live stock, to reduce the chance of overgrazing
- Rotate where the livestock ae kept to allow the plants to have a chance to grow back/re-establish
Why are pesticides and inorganic fertilisers used
Used to control pests, weeds and disease, and the use of synthetic chemicals to aid plant growth (Fertilisers include N, P and K)
What is the impact of pesticides and inorganic fertilisers on biodiversity
- Contaminate soil and local water, impacting local wildlife
- Kills pollinators, reducing crop yield and damaging the interdependence within the ecosystems
- Fertilisers cause fast growing plants to dominate, impacting natural selection
How can the impacts of pesticides and inorganic fertilisers be reduced
- Using less (finding alternatives:)
- Genetically modified crops that are resistant to pests, disease, etc.
- Crop rotations to increase soil fertility and reduce the need for fertilisers
- Use biological controls to remove pests (eg. Introduce ladybirds, to reduce aphid population)
What is silage and why is it important
Fermented green crops, increasing it’s nutrients, to be fed to cattle, sheep and other livestock
What is the impact of effluent escape from silage stores on biodiversity
Causes Eutrophication:
- Silage in water stores increases the nutrient content
- Increased activity of decomposers
- Oxygen is used up, so wildlife dies
- Increased plant growth (algae blooms) blocks light and uses up resources, harming the biodiversity
How can the impacts of effluent escape from silage stores be reduced
- Only cut the crop when it is dry and has wilted for 24hrs, to reduce effluent silage
- Have effluent channels that are regularly inspected, to capture and silage
- Store silage in bales to reduce effluent silage
- Store in secure containers, at least 20m from a waterbody
- Have frequent water quality assessments to ensure silage isn’t ending up there, and so it can be dealt with faster if it is.
What is intercropping
When you grow two or more crops with different nutrient requirements in the same field
What is crop rotaion
Planting different crops sequentially on the same plot of land
What is the impact of no intercropping/crop rotations on biodiversity
- Leads to the depletion of nutrients
- Increases the impact of crop specific diseases/pests
- Reduces the biodiversity, as less species are present, damaging the interdependence relied upon by the local ecosystem
What are the benefits of intercropping
- Saves space
- Reduces resources needed
- Increases crop yield (more profit)
- Increase the biodiversity of the field
What are the benefits of crop rotations
- Reduces a depletion of nutrients, as different crops have different requirements
- Reduces the impact of crop specific pests/diseases
What are the 4 ways genetic diversity between organisms/species can be compared
- Observable characteristics
- DNA base sequence
- mRNA base sequence
- Amino acid sequence in proteins (Immunological comparisons)
How can genetic diversity be compared based on observable characteristics
- Phenotype determined by genes, so suggests genetic diversity
- Not reliable, as polygenetic characteristics can be altered by environmental factors (Differences may not mean no evolutionary links)
How can genetic diversity be compared based on the DNA base sequence
- DNA sequencing and computer analysis allows for DNA sequences to be compared
- More similar DNA suggests closer evolutionary links
How can genetic diversity be compared based on the mRNA base sequence
- mRNA is coded for by DNA, so similarities/differences reflect those in the genome
How can genetic diversity be compared based on the amino acid sequence in proteins
- Amino acids are coded for by mRNA, which is determined by DNA, so similar protein structures suggest closely related species (evolutionary links)
What is the principle that allows immunological comparisons to be made
Antibodies of one species will respond to specific antigens on the proteins in the blood serum of another species
What is the process to carry out immunological comparisons
- Inject human blood serum containing albumin (protein) into a rabbit
- Rabbit produces antibodies against human albumin
- ‘Anti-human albumin’ are collected and purified
- Antibodies are added to the blood serum of other species
- A precipitate forms if there is an immune response, showing that human-like proteins are present
∴ Species with more precipitate = more closely related to humans
What is interspecific variation
If one species differs from another
What is intraspecific variation
If members of the same species differ from each other
What is random sampling
Taking measurements from a randomly selected group of the population, which should represent the whole population
What factors can effect random sampling
- Sampling bias: Individuals may be favoured for selection, effecting how representative the sample is
- Chance: The random nature of the sample means it many not be representative just due to chance (no bias)
What is a normal distribution curve
Bell curve that shows the distribution of continuous traits (eg. Weight)
What is the arithmetic mean (x̄)
Sum of the samples / number of items
(max height of the normal distribution curve - not if skewed)
What is the mode
The most common value
(max height of normal distribution curve - even if skewed)
What is the median
Middle of the set of data
(max height of the normal distribution curve - not if skewed)
What is standard deviation
Mean average of the distance of the values from the mean
How do you calculate standard deviation
SD = √ Σ(x-x̄)^2 / n-1
What proportion of the data lies within ±1SD from the mean
68%
What proportion of the data lies within ±1.96SD (~2)
95%
What is standard error
The expected standard error of the mean
How can you calculate standard error
SE = SD / √n
In what proportion of the data could the mean lie with ±1.96SE
95%
