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29 Cards in this Set
- Front
- Back
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A method, used by biologists, that reflects on an evolutionary history, grouping closely related organisms together...
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Phylogenetic method
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On a phylogenetic tree if organisms are grouped closely or have many similar characteristics, this shows they have...
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A common recent ancestor.
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What is classification?
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The placing of organisms into groups.
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What is a hierarchy?
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A system of ranking in which small groups are nested components of larger groups.
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Hierarchy of Biological classification from largest taxon to smallest. (Do Keep Ponds Clean Or Fish Get Sick) |
Domain Kingdom Phylum Class Order Family Genus Species |
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Why do we need a classification system.
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- If a new animal is discovered, we can predict some of it's other characteristics, based on our general understanding of other animals.
- When we communicate it is quicker to say 'bird' instead' listing all its characteristics.
- A phylogenetic classification system allows us to infer evolutionary relationships. ( if 2 organisms in the same taxon, we can infer they are closely related).
- More useful to count families rather than species when describing the health of an ecosystem or rate of extinction.
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What are the 3 domains in the 3 Domain System?
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Domains defined on similarities in DNA base sequence. 1. Eubacteria - Prokaryotes (E.coli & Salmonella) 2. Archaea - Bacteria with unusual metabolism (also a prokaryote). -Live in marine habitats. -Have a cell wall (no chitin & no cellulose - sometime peptidoglycan). 3. Eukaryota - All eukaryotic cells containing a membrane bound nucleus. |
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What are the 5 Kingdoms?
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1. Prokaryota - Unicellular - All bacteria & cyanobacteria (blue-green algae). - No membrane-bound organelles. - Saprophytic, parasitic or autotrophic.
2. Protoctista - Unicellular - Has a nucleus -Some form colonies of identical cells. -Amoeba have animal like cells while Euglena have cells like plants and animals. - Heterotrophic
3. Fungi - Yeast are unicellular. - Moulds & mushrooms are multicellular. - have hyphae that weave together to form the body of the fungus. - Septa sub-divide the hyphae. -Heterotrophic & Saprophytic
4. Animalia - 35 animal phyla - Show nervous co-ordination - Most are motile at some stage of their life. - Heterotrophic
5. Plantae - Simple reproduce with spores (mosses & ferns). - Complex reproduce with gametes ( flowering plants & conifers). - Autotrophic.
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What does heterotrophic mean?
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Eats other organisms
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What does autotrophic mean?
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Produces its own food.
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What does saprophytic mean?
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Secretes enzymes which digest the food outside the cell which then get reabsorbed.
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What is a phylum? |
A sub-group of a kingdom. - Members of each phylum have a distinct body plan, e.g Annelida - soft bodies & segmented Arthropoda - chitinous exoskeleton & jointed limbs Chordata - contains the vertebrates |
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What is a class?
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A sub-group of a phylum. E.g Mammalia - in Animalia insecta - in Arthropoda |
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What is a order?
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Sub-group of class E.g Lepidoptera containing butterflies in the class insecta |
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What is a family?
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A group within an order. E.g rose family Rosaceae |
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What is a genus?
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A group of similar organisms such as the genus Panthera containing lions & tigers.
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What is a species?
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A group of organisms sharing a large number of physical features that are able to interbreed to produce fertile offspring.
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What is taxonomy & what does it allow?
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The identification & naming of organisms. It allows us to: - Discover & describe biological diversity -Investigate he evolutionary relationship between organisms. - Classify organisms to reflect their evolutionary reltionships. |
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3 advantages of the binomial system?
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1. Unambiguous naming 2. Based on Latin, a scholarly language that can be used all over the world. 3. Implies that 2 species sharing part of their name are closely related. |
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What are homologous structures?
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-Structures that have different functions but have a similar form of developmental origin. - Indicates a more recent common ancestor. E.g Pentadactyl limb |
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What is divergent evolution?
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Where a common ancestral structure has evolved to perform many different functions E.g Homologous Structures. |
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What are analogous structures?
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-2 animals look similar but may not be closely related. -Don't have a common ancestor but have survived in the same conditions. E.G whales & dolphins / Butterflies & Bats |
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What is convergent evolution?
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Where structures have similar properties but different developmental origins. E.G Analogous Structures |
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5 Techniques for analysing relationships using genetic evidence
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1. DNA Sequences 2. DNA Hybridisation 3. Gel Electrophoresis 4. Amino Acid Sequences 5. Immunology |
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Discuss DNA Sequences as a technique for analysing relationships.
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The more closely related species are the more similarities shown in their base sequence. - This technique has confirmed relationships & corrected mistakes. |
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Discuss DNA Hybridisation as a technique for analysing relationships.
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-DNA is extracted from both species, separated & cut into fragments. -Fragments from 2 species are mixed & hybridise where base sequences are complimentary. - The new DNA is heated, the higher the temp. needed to break the H bonds the more closely related species are. |
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Discuss Gel Electrophoresis as a technique for analysing relationships.
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This measures the proportion of DNA & proteins shared between species to estimate the relatedness. (Looks like chromatography) |
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Discuss Amino Acid as a technique for analysing relationships.
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The more closely species are the more similarities (& less differences) found in their amino acid sequences.
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Discuss Immunology as a technique for analysing relationships.
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-If you mix the antigens, with specific antibodies of another species, a precipitate will form. -The closer evolutionary relationship between 2 species the more precipitate formed (more antibody & antigen react). |
