Species

?
Define Taxonomy.
Describing, naming and classifying organisms.
1 of 35
How are species ordered?
Hierarchal system - levels of increasing similarity
2 of 35
What are phylogenetic relationships?
Evolutionary lines linking species
3 of 35
Why use a binomial naming system?
Every species gets a unique combination of two names. One =genus. One=species . Able to see which species are most directly related to each other.
4 of 35
What are the current groups at the top of the hierarchy?
Domains- Bacteria, Archae, Eukarya
5 of 35
How are Bacteria, Archaea and Eukarya grouped together?
Comparing the genetic sequences of their ribosomal DNA
6 of 35
What do viruses not fit within the current hierarchial system?
Viruses- Outside mainstream classification- (replicate only within hijacked living cell).
7 of 35
Why do lichens not fit within the 3 domains classification system?
Belong to more than one genotype (Chimeras) - close association of fungal+algal cells. Classified on basis of fungal partners as sometimes more than one species of algae can be involved.
8 of 35
What do all eukaryotes have in common?
DNA wound around proteins within a nuclear membrane.
9 of 35
What are monerans?
Species with no distinct nucleus e.g Bacteria, Archaea.
10 of 35
What is the Endosymbiant theory as proposed by Lynn Margulis?
Organelles e.g. chloroplasts + mitonchondria = derived from prokaryotic cells that combined symbiotically with a host cell. =eukaryotes with membrane-bound organelles. Explains- own DNA + similar size to photosynthetic/chemosynthetic bacteria
11 of 35
What could make classification using shared morphology difficult?
Polymorphic species. Convergent evolution can occur- natural selection produces species with similar features- Homoplasy.
12 of 35
What is an apomictic species?
One that can produce seed without being pollinated.
13 of 35
Why is comparing protein compositions key in identifying species?
Some proteins=present in most organisms e.g. Cytochrome (in all living organisms for energy generating in mitochondria + chloroplasts) first 33 amino acids=same. then different order in each species.
14 of 35
How is DNA fingerprinting carried out?
Using PCR (polymerase chain reaction). - Amplify DNA fragments with tagged bases. The more fragments that are shared by two species /individuals the closer they are related.
15 of 35
What else can be analysed from a plant to determine its species excluding DNA?
Scent/chemical signals used to attract pollinators etc. Most species are different chemotypes.
16 of 35
What is the ecological species concept?
Where you recognise a species by its role in the environment.
17 of 35
What does the distribution of most species look like on a graph?
Normally distributed- species have an optimum range with most individuals close to the mean value.
18 of 35
Why are most species normally distributed on a graph of range?
Because most are adapted to specific conditions. The further away from the optimum-the less favorable the conditions are.and the higher the physiological costs.
19 of 35
When might it be an advantage to have different adaptations to the norm?
Possible resistance to a strain of disease, changing environmental conditions etc.
20 of 35
What is a neutral variation?
When there is no selective advantage or cost.
21 of 35
What are generalist species?
Where species can occupy a wide variety of ecological roles and environments- able to exploit many different resources. Good strategy in unpredictable habitats.
22 of 35
What are specialist species?
Highly adapted and efficient in exploiting specific resource/s. Will outcompete others for the resource however will do badly if environmental conditions change too rapidly.
23 of 35
What is a niche overlap?
When two species occupy the same part of the resource spectrum.
24 of 35
What is the fundamental niche?
The range absent from interference from other species.
25 of 35
Define: allopatic speciation
Separation by space
26 of 35
Define: sympatric speciation
Incompatible gene pools
27 of 35
What are the types of reproductive barriers? List some examples.
Pre-zygotic- Mechanical, behavioural, physiological. Post-zygotic-mismatch in number of chromosomes.
28 of 35
Is polyploidy more common in animals or plants?
Plants. Rarely produces viable or fertile offspring in animals.
29 of 35
What is polyploidy?
Where gametes have multiple copies of chromosomes. There are not haploid.
30 of 35
What happened to the common bend grass races growing on abandoned copper mines in North Wales?
Metal-tolerant-lives in marginal land due to: Parapatric speciation- Small, isolated and rapidly reproducing population= inbreeding-highly adapted populations n discrete and distinct habitats.
31 of 35
How many plant cultivars is there predicted to be? And from how many wild species?
70,000 from around 1,100 wild.
32 of 35
Examples of GM crops?
Round-up ready soya
33 of 35
What solution could prevent the formation of superweeds from cross-over between wild plants and GM crops?
Engineer the genes on the chloroplasts so they can only be passed down the maternal line- no species cross-over?
34 of 35
What is an ecological problem of genetically modifying crop species to produce their own pesticides? Example.
Non-target species affected. E.g Monarch butterfly larvae are poisoned by the Bt toxin plants that have an endotoxin gene from Bacillus thuringiensis.
35 of 35

Other cards in this set

Card 2

Front

How are species ordered?

Back

Hierarchal system - levels of increasing similarity

Card 3

Front

What are phylogenetic relationships?

Back

Preview of the front of card 3

Card 4

Front

Why use a binomial naming system?

Back

Preview of the front of card 4

Card 5

Front

What are the current groups at the top of the hierarchy?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Environmental Science/Studies resources:

See all Environmental Science/Studies resources »See all Ecological Principles resources »