Biodiversity, species and taxonomy Flashcards
What is biodiversity? (2)
Number of species and the number of individuals of each of the species within any one community
What is species richness? (1)
Number of different species in a community
What is a community? (1)
All the individuals of all the species living together in the same area at the same time
What is genetic diversity? (1)
Difference in DNA/base sequence/alleles/genes
What is a niche? (3)
An organism’s role in an ecosystem/community
It describes what the species is like, where it occurs, how it behaves, how it interacts with other species and how it responds to the environment
Species sharing the same niche will compete with each other
What is a habitat? (1)
A place where an organism normally lives within an ecosystem
Compare and contrast species richness and index diversity (2)
Both species richness and index of diversity take into account the number of different species present in a community
Index diversity takes into account number of individuals for each species in a community but species richness does not take into account individuals
How to calculate an index of diversity for a particular community? (2)
Number of species
Number of individuals in each species
The number of species present is one way to measure biodiversity.
Explain why an index of diversity may be a more useful measure of biodiversity (2)
Also measures numbers of individuals in a species
Some species may be present in low/high numbers
Give 2 advantages of using an index of biodiversity rather than an indicator species (2)
You do not need to identify each species
Index considers the number of organisms of each of the species
Suggest one economic argument for maintaining biodiversity (5)
Medical/pharmaceutical uses
Commercial products
Tourism
Agriculture
Saving local forest communities
How does farming reduce species diversity? (4)
Natural plants and animals are lost when the land is cleared, ploughed etc - these activities may reduce variety of food sources and habitats and niches
Growth of species crops/ animals occurs - growth of other species is controlled or stopped
Pesticides and herbicides may be used to kill unwanted species
Fertilisers are designed to encourage growth of specific crops
The forest was cleared to make more land available for agriculture.
After the forest was cleared the species diversity of insects in the area decreased. Explain why (4)
Decrease in variety of plants/fewer plant species
Fewer habitats/niches
Decrease in variety of food/fewer food sources
Aspect of clearing forest (killing insects) eg machinery, pesticides
Framers clear tropical forests and grow crops instead. Explain how this causes the diversity of insects in the area to decrease (5)
Lower diversity of plants/few species of plants
Few sources of food
Few habitats/niches
Fewer species of herbivore so few species of carnivores
Aspect of agriculture (killing insects)
How can biodiversity be increased in areas of agriculture (3)
Use hedgerows instead of fences
Grow different crops in the same area or rotate crops around after a season
Limit use of pesticide and herbicide
What is classification? (1)
Arranging organisms into groups
What is taxonomy?
The theory and practice of biological classification
What is the taxonomic hierarchy? (8)
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
Explain what is meant by a hierarchy (2)
Smaller groups within larger groups
No overlap between groups
Explain what is meant by phylogenetic group (1)
The study of patterns of evolutionary history
What does courtship behaviour mean? (2)
Behaviour that results in mating and eventual reproduction
Genetically determined
Give 2 ways in which courtship increases the probability of successful mating (advantages of courtship behaviour) (5)
Attracts/recognises the same species
Attracts/recognises opposite sex/mate
Indication of sexual maturity/fertility/synchronise mating
Stimulates release of gametes
Form pair bond
How to compare genetic diversity between organisms (4)
The frequency of measurable or observable characteristics
The base sequence of DNA
The base sequence of mRNA
The amino acid sequence of the proteins encoded by DNA and mRNA
What is the problem with using observable features to place organisms into groups (2)
Leads to mistakes because some species look similar but have not shared common ancestor recently
Not reliable
In classification, comparing the base sequence of a gene provides more information than comparing the amino acid sequence for which the gene codes. Explain why (3)
More bases than amino acids
Introns/non-coding DNA
Same amino acid may be coded for /DNA code is degenerate
Comparing the base sequence of genes provides more evolutionary information than comparing the structure of proteins. Explain why (3)
More bases than amino acids
Introns/non-coding DNA
More than one code for each amino acid
Give two ways doctors could use base sequences to compare different types of
HPV (3)
Compare DNA base sequence
Compare mRNA base sequence
Look for mutations
What advantage does a high genetic diversity provide? (2)
Ability to adapt to a change in environment
Allows natural selection to occur
Describe how comparisons of biological molecules in two species could be used to find out if they are closely related (8)
Compare DNA
Sequence of bases/nucleotides
Compare Cytochrome C (mitochondria) same/named protein
Sequence of amino acids/primary structure
Inject serum/protein into animal
Obtain antibodies/serum
Add protein/serum from other species
Amount of precipitate indicates relationship
What is a population? (1)
All the organisms of a species living in the same area at the same time
Define species (1)
Group of similar organisms that can interbreed to produce fertile offspring
What system is used to give species a universal name (1)
Binomial naming system
How are binomial names handwritten (2)
First letter of the genus name should be capitalised, with the rest in lowercase
The whole name should be underlined
What is phylogenetic classification? (1)
Process of arranging organisms into groups based on their evolutionary origins and relationships
What is meant by interspecific and intraspecific competition? (2)
Interspecific - competition between individuals of different species
Intraspecific - competition between individuals of same species
