Biodiversity, Species and Taxonomy Flashcards
Biodiversity, Diversity index, Ecosystem stability, Farming, Taxonomy, The classification system, Phylogenetics, Courtship behaviour, Modern classifaction methods, Method of direct comparison, Proteins, Immunological comparisons
The number of species and the number of individuals of each of the species within any one community
Biodiversity
A measure of the number of different species in a community
Species richness
All the individuals of all the species living together in the same area at the same time
Community
A group of similar organisms that can reproduce and produce fertile offspring
Species
Variety of species in a community
Diversity
What does a higher value in the diversity index mean?
A higher value of d the greater the species diversity
The place where an organism lives within an ecosystem
Habitat
d
Species diversity
N
Total number if organisms of all species
n
Total number of organisms of each species
What is ecosystem stability?
The greater the diversity the more stable the ecosystem is because with a wide range of organisms, it is less likely a disease or a change in climate will affect every organism, allowing the ecosystem continue to exist.
Name four economic arguments for maintaining diversity
- Medical/pharmaceutical uses
- Tourism
- Agriculture
- Saving local forest communities
What is the impact of farming?
It tends to reduce diversity
Four reasons farming reduces diversity are:
- Natural plants and animals are lost when the land is ploughed
- May reduce food sources and habitats
- Growth of specific crops/animals occurs and growth of other species is controlled/stopped
- Pesticides and herbicides may be used to kill unwanted species and fertilisers are designed to encourage the growth of specific crops
The science of classification
Taxonomy
What does taxonomy involve?
Naming and grouping organisms according to shared characteristics which allows scientists to identify and study organisms, and then compare their findings
What do scientists use to give species names?
Binomial system, which means each species has a two-worded scientific name that is universal
What is the first word of a species name
Genus
What is the second word of a species name
Species
How are scientific names written?
Usually in italics or underlined
The species is all in lowercase (e.g. Homo sapien)
What is the classification system?
Organsisms are placed into taxa based on their shared characteristics
What is special about the classification system?
It is a hierarchical system so groups are within groups and there is no overlap
What is the first group within the hierarchy?
Domain
What is the second group within the hierarchy?
Kingdom
What is the third group within the hierarchy?
Phylum
What is the fourth group within the hierarchy?
Class
What is the fifth group within the hierarchy?
Order
What is the sixth group within the hierarchy?
Family
What is the seventh group within the hierarchy?
Genus
What is the eighth group within the hierarchy?
Species
What mnemonic can be used to help remember the order?
Delicious King Prawn Curry Or Fat Greasy Sausages
What is meant by a phylogenetic group?
Grouped according to evolutionary links/history/relationships/common ancestry
How are organisms which share the same common ancestor shown on a phylogenetic tree?
Have branches closer together/branching off from each other
Whys is courtship behaviour carried out?
To attract a mate of the same species. Courtship behaviour is important to reproductive success
How is courtship behaviour determined?
Genteically, so organisms more closely related display similar patterns of courtship behaviour
Give three examples of courtship behaviour
- Fireflies give of pulses of light - each species has a specific pattern
- Many birds have specific displays - each species has displays a different pattern of movements within displays
- Male butterflies release chemicals - different for each species
What were the original classification based off?
Observable features
What do scientists use to class animals?
Genetic and molecular evidence
What does DNA tell scientists about the relation of two species?
The more closely elated the species the similar the DNA will be
How is DNA hybridisation performed?
. Take DNA from the two species you want to compare and heat to break the H bonds between the strands separating them
. Mix DNA and cool - producing DNA hybrids
. Increase the temperature in small increments
. Measure the amount of hybrid DNA which is still double stranded at each temperature
What do the results of hybridisation mean?
The more similar the species the higher the temperature required to break the H bonds and separate the two strands
What do proteins tell scientist about the relation of two species?
Proteins are coded by DNA, so the more similar the amino acid sequence the more similar the DNA sequence and therefore the more closely related the two species are
What does immunological comparisons tell scientist about the relation of two species?
If antibodies made in response to one species protein are able to bind to the proteins for another species and clump, they shared an ancestor more recently in time
