4.3 (10) - Biodiversity Flashcards
Species and taxonomy Diversity within a community Species diversity and human activity Investigating diversity Quantitative investigations of variation
What is a species?
Individuals capable of breeding to produce living, fertile offspring
How do you name a species?
- Binomial system (2 names), based on Greek and Latin names
- First (generic) name: name of the genus that the organism belongs to
- Second (specific) name: indicates the species to which they organism belongs
- When typing, use italics, or underline when handwriting
- First letter of first name = uppercase, first letter of second name = lowercase
What is courtship behaviour?
The signs that are displayed by members of the same species, in order to try and mate with each other
What are some examples of courtship behaviour?
- Recognising members of their own species to produce fertile offspring
- Identifying a mate capable of breeding
- Forming a pair bond
- Synchronise mating (when female is in season)
- Become able to breed (change physiologically)
What is classification?
Grouping organisms together
What is taxonomy?
The theory and practice of classification
What are 2 types of classification?
- Artificial classification
- Phylogenetic classification
What is artificial classification?
Dividing organisms according to differences that are useful at the time
What is phylogenetic classification?
Classification based upon evolutionary relationships, classifies species into groups and arranges these groups into a hierarchy.
What are the 8 taxonomic ranks
Domain → kingdom → phylum → class → order → family → genus → species
What are the 3 domains?
- Bacteria
- Archaea
- Eukarya
What are bacteria like?
- No membrane-bound organelles
- Unicellular (single celled)
- Ribosomes are smaller (70S), compared to eukaryotic cells
- Cells walls made of murein
- Single loop of DNA (naked), with no histones attached
How are archaea different to bacteria?
- Genes and proteins are synthesised more similarly to eukaryotes
- Cell walls do not contain murein
- Membranes contain fatty acid chains and glycerol attached via ester bonds
- Complex form of RNA polymerase
What are eukarya like?
- Cells contain membrane-bound organelles
- Membranes contain fatty acid chains and glycerol attached via ester bonds
- Not all have a cell wall, but if they do, no murein is present
- Ribosomes are larger (80S) than bacteria and archaea
- Divided into 4 kingdoms
What does ‘biodiversity’ mean?
A term used to describe variety in the living world
What are 3 types of biodiversity?
- Species diversity
- Genetic diversity
- Ecosystem diversity
What does ‘species diversity’ mean?
The number of different species and the number of individuals of each species there are within a community
What does ‘genetic diversity’ mean?
The variety of genes possessed by the individuals that make up a population of a species
What does ‘ecosystem diversity’ mean?
The range of different habitats, from a small local habitat to the whole Earth
What are some agricultural factors that reduce biodiversity?
- Using pesticides
- Over-grazing
- Deforestation
- Draining aqueous environments
- Pollution
- Not allowing time for the ‘fallow period’
- Not rotating crops
- Breeding/creating monocultures
- Removing hedges
How can we conserve and maintain biodiversity?
- Protect more areas of land (with laws)
- Use organic fertilisers
- Create natural meadows (where lots of crop species can grow) - stop planting monocultures
- Reduce the use of pesticides - use biological agents instead
- Keep hedges
- Maintain ponds and wetlands
- Planting more trees
- Eating less/no meat
- Restoring ruined habitats
What is the meaning of ‘interspecific variation’?
Differences between different species
What is the meaning of ‘intraspecific variation’?
Differences within members of the same species
What 2 reasons might a sample not be representative of a whole population?
- Sampling bias
- Chance
Under what circumstances is random sampling most effective at avoiding sampling bias?
- When a large sample size is used
- When data analysis is performed
Both of these methods can reduce the effect of chance, too.
How do you calculate the mean of a set of data?
Add all the numbers up and divide the total by how many numbers there are.
How do you calculate the median of a set of data?
The middle number when the numbers are all arranged in ascending order.
How do you calculate the mode of a set of data?
The number that appears the most frequently.
What is a normal distribution curve?
A bell-shaped curve, typical of features that show continuous data (eg. height and weight).
What does the mean look like on a normal distribution curve?
The maximum height of a normal distribution curve.
What does ‘standard deviation’ mean?
The distance from the mean to the point where the curve changes from being convex to concave (point of inflection).
What does the standard deviation give a measure of?
The standard deviation gives a measure of the range of values either side of the mean.
