Classification + Biodiversity Flashcards Preview

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Flashcards in Classification + Biodiversity Deck (50):
1

Biodiversity:-

A measure of the number of different species and the number of individuals in each species in a given environment.

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Species:-

A group of organisms with a large number of common characteristics and could be interbred to produce fertile offspring

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Spacial biodiversity variation:-

Biodiversity generally increases moving towards the equator with the greatest biodiversity found in the tropics. Tropical rain forests and coral reefs = most diverse habitats in world.

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Biodiversity variation over time:-

Can increase or decrease due to:-
Sucession
Natural selection
Human influence

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Sucession(3):-

•Over time a community of organisms changes its habitat, making it more suitable for other species.
•This change in composition of a community over time is called succession.
•It increases animal biodiversity but ultimately decreases plant biodiversity.

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Human influence on ocean biodiversity:-

Over fishing has depleted fish stocks.

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Human influence on tropical rainforest biodiversity:-

Deforestation for farming, roads and industry has destroyed habitats.

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Human land misuse influence on biodiversity:-

Trampling by cattle w/ increased temp due to climate change has increased area of deserts.

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Human pollution influence on biodiversity:-

Rivers poluted with industrial chemicals e.g. Yangtze River Dolphin extinct in 2006.

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Significance of biodiversity:-

•A small number of plant species provide staple foods e.g. wheat and rice.
•Living organisms provide important raw materials e.g. rubber/cotton.
• medicinal drugs are derived from plants and fungi e.g. digoxin for heart disease comes from digitalis (foxglove).
•As biodiversity decreases, we lose potential undiscovered resources.

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3 levels of assessing biodiversity:-

Habitat level- counting no. of individuals and species.
Genetic level-examining genes.
Molecular level- examining DNA and proteins.

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Genetic level assessing:-

Examining all the alleles in the gene pool of a population rather than individuals

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Gene pool:1

All the different alleles of all the diff genes in a population. No of different alleles in pool of species = genetic diversity.

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Gene locus:-

A gene's position on a chromosome

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Polymorphic genes:-

More than 1 allele at the same locus.

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Polymorphism:-

The occurrence of more than 1 phenotype in a population that cannot be caused by mutations.

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Sampling techniques:-

Quadrats
Transects
Sweep nets
Kick sampling in a stream.

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Simpson's diversity index:-

Gives value between 0 and 1. Higher value= higher biodiversity.

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Molecular level assessing:-

Done using DNA sample fingerprinting and sequencing. Sometimes base sequence mutations occur, giving rise to non-coding sequences that give a unique DNA fingerprint. Can accumulate across generations, giving rise to a quite different DNA profile. Comparing these in different organisms shows how closely related they are. Greater difference= greater biodiversity.

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DNA fingerprint/profile:-

Terms for a pattern unique for each individual, related to the base sequence of their DNA.

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Natural selection:-

The gradual process in which inherited characteristics become more or less common in a population, in response to the environment determining the breeding success of individuals possessing those characteristics.
Theorised as reason for evolution by Darwin in 1859.

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Natural selection stages(6):-
Mario Very Cleanly Sprints Really Pacily

Mutation.
Variation.
Competitive advantage.
Survival of the fittest.
Reproduction.
Pass advantageous alleles onto offspring.

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Adaptation:-

The changes in species, as a useful characteristic becomes more common.
Specific characteristic = adaptive trait.

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Adaptation types:-

Anatomical
Physiological
Behavioural

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Classification:-

The arrangement of organisms into discrete and hierarchical groups with other closely related species.

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Taxonomy:1

The branch of biology concerned with naming and classifying organisms.

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Phylogenetic tree:-

Shows evolutionary history of diff species and indicates common ancestors and lines of descent. Closer branches= more recent point of divergence from common ancestor and therefore, the closer the evolutionary relationships.

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Linnaean taxonomy:-

Basis of system used today. Made by Carl Linnaeus. Uses hierachy approach and a binomial system.

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Order for hierachical classification (use Dominic King Palethorpe Chokes On Families' Gay Spunk)

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

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Hierarchical system exta info:-

Each feoup has unique features (discrete, no overlap). Organisms more closely related going down group.

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Binomial system:-

Capitalised gemus followed by lower case species. Written in italics or underlined.

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3 advs of binomial system:-

Unambiguous naming.
Based in Latin so avoids confusion of local common names and different languages.
Shows relation by sharing parts of names.

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Tentative nature of classification systems:-

Based on current knowledge so it may alter as new evidence emerges leading to organisms changing groups.

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Need for classification system (4):-

•if a new animal is discovered, we can predict some of its other characteristics.
•easier to identity organism by a name.
•conservationists find it more useful to count families than species when describing changes in an ecosystem.
•phylogenetic system allows us to infer evolutionary relationships by putting them in the same taxon.

35

Taxon:-

A group within this classification hierachy and is a collection of organisms sharing basic features.

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3 domains:-

Bacteria(eubacteria):- often called true bacteria.
Archaea(archaeabacteria):extremophile bacteria.
Eukaryota.
3 DOMAIN THEORY.

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5 kingdoms:- (use FAPPP)

Fungi
Animalia
Plantae
Protoctista
Prokaryotae

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Prokaryotae:-

All bacteria.
All unicellular, no membrane bound organelles.
Murein cell wall

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Protoctista:-

May have characteristics of animal or plant cells or both. Mostly unicell but can be multi(seaweed or algae). Membrane bound organelles.

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Plantae:-

Plants

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Fungi:-

Can be uni (yeast) or multi (mushroom). Chitin cell walls.

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Animalia

Animals

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Classes:-

Fish
Amphibians
Reptiles
Birds
Mammals

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Homologous structures:-

Structures that all share a common form. Used w/molecular data to construct phylogenetic trees. Derived from common ancestor, structurally the same but may be adapted to a diff function.

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Homologous structure example:-

Pentadactyl limb (5 digits) found in mammals, birds reptiles and amphibians. E.g. Human arm and bird wing structurally the same but have adaptation to a different function.

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Divergent evolution:-

When a common ancestral structure evolves to perform different functions.

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Analogous structures:-

Have the same function but don't share the same structure and aren't derived from a common ancestor.

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Convergent evolution:-

The tendency of unrelated organisms to acquire similar physical structures (in response to their environment).

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Species:-

A group of organisms with similar physical characteristics that can interbreed to produce fertile offspring.

50

Gel electrophoresis:-

DNA fragments or proteins are displayed as bands on an electrophoresis gel. DNA SEQUENCING. Can reduce mistakes made in classification due to convergent evolution.