12.14 Biodiversity, Taxonomy and Classification Flashcards
Biodiversity
The no. species + no. individuals of each species within any one community
Species richness
No. of different species in a community
Community
All the individuals of all the species living together in the same area at the same time
Species
Group of similar organisms / organisms with similar features / / organisms with same genes / chromosomes;
Reproduce to produce fertile offspring;
Genetic diversity
- Difference in DNA
- The number of different alleles of genes in a population
Niche
An organisms specific role in the community (how it interacts with other species, how it responds to the environment)
Habitat
A place where an organisms normally lives within an ecosystem
How to calculate the diversity index
Draw equation
d= N(N-1)/E n(n-1)
d= species diversity index
N= total no. organisms of all species
n= total no. organisms of each species
E= sum of
Explain why an index of diversity may be a more useful measure of biodiversity
- Measures number 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
- You do not need to identify each species
- Considers the number of organisms of each species
Suggest one economic argument for maintaining biodiversity
- Medical uses
- Commercial products (must give examples)
- Tourism
- Agriculture
- Saving local forest communities
Relationship between diversity and stability
The more DIVERSE an ecosystem the MORE STABLE that ecosystem is
How does farming affect diversity?
- Tends to reduce species diversity
- Farming activities may reduce variety of food sources and habitats and niches
- Growth of one species occurs while growth of another species is controlled
- Pesticides and herbicides may be used to kill unwanted species
- Fertilisers are used to encourage growth of specific crops
A 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;
Farmers clear tropical forest and grow crops instead. Explain how this causes the diversity of insects in the area to decrease.
- Lower diversity of plants/ few species of plants/less variety of plants/few plant layers;
- Few sources/types of food/feeding sites;
- Few habitats/ niches;
- Fewer (species of) herbivore so few (species of) carnivores;
- Aspect of agriculture (killing insects);
Classification
Grouping of organisms
Taxonomy
Theory and practice of classification
What is the system for naming species?
Binomial system is universal
- Genus + Species
- e.g. Homo sapiens
What is the classification system?
- 8 Levels of taxa (GROUPS) and organisms only belong to one at each level
- Creates a hierarchy
-NO OVERLAP- organisms belong to one taxon only
8 levels of taxon
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
‘Dont Kill Phil Cos Other Females Get Scared’
Types of domain
Bacteria
Archaea
Eukarya
Kingdoms of Eukarya domain
Protctista
Fungi
Plantae
Animilia
Explain what is meant by a heirarchy
- Groups within groups;
- No overlap (between groups);
Explain what is meant by a heirarchy
- Groups within groups;
- No overlap (between groups);
Explain what is meant by a phylogenetic group
(Grouped according to) evolutionary links/history/relationships / common ancestry;
Process of courtship behaviour
- Organisms TO ATTRACT A MATE of the RIGHT SPECIES and RIGHT SEX, carry out courtship behaviour
- Ensures reproductive success
- Genetically determined, organisms closely related display similar patterns of courtship behaviour
Give two ways in which courtship increases the probability of successful mating
- Attracts/recognises same species
- Attracts/recognises opposite sex
- Indication of sexual maturity
- Stimulates release of gametes
- Form a pair bond
Modern classification methods uses…?
- The frequency of measurable/observable characteristics
- The base sequence of DNA
- The base sequence of mRNA
- The amino acid sequence of proteins
In classification, comparing the base sequence of gene provides more information than comparing the amino acid sequence for which the gene codes
Explain why?
- More bases than amino acids
- Introns
- DNA code is degenerate
Explain how natural selection produces changes within a species.
- Variation [caused by mutation] between members of population / species;
- Predation / disease / competition results in differential survival;
- Some have adaptations that favour survival;
- Differential reproductive success / survive to reproduce/ have more offspring/
- Pass on their advantageous alleles /
- Changes allelic frequencies
Scientists’ analysis of blood proteins has indicated a lack of genetic diversity in populations of some organisms.
Describe the processes that lead to a reduction in the genetic diversity of populations of organisms. (6)
- Mark for general principle of - reduced variety/number of different alleles/DNA / reduced gene pool (in new population);
- Founder effect;
- A few individuals from a population become isolated/form colonies:
- (Genetic) bottlenecks;
- (Significant) fall in size of population
- Selective breeding / artificial selection;
- Using organisms with particular alleles / traits / phenotypes / characteristics
What is meant by a genetic bottleneck.
- Sudden decrease in population / many killed by an event eg earthquake;
- Idea of reduced/low genetic variation/diversity / reduction in (variety of) alleles / smaller gene pool;
Suggest one ethical argument for maintaining biodiversity.
Prevent extinction /loss of populations/ reduction in populations /loss of habitats / save organisms for future generations
