ANWSER
Question 1a:
Answer:
The three rules of taxonomy adopted by the International Code of Botanical Nomenclature (ICBN) in 1886 are:
1. Principle of Priority: The earliest validly published name for a taxon takes precedence.
2. Principle of Typification: Each taxon must be associated with a designated type specimen.
3. Requirement of Latin Diagnosis: New plant species must include a description or diagnosis in Latin.
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Question 1b:
Answer:
The criteria for valid publication of a taxon name include:
1. Publication in a widely accessible, peer-reviewed journal or book.
2. A description or diagnosis in Latin (post-2012, English is allowed under the Shenzhen Code).
3. Designation of a type specimen deposited in a recognized herbarium.
4. Compliance with the rules of the ICBN (e.g., correct formatting, no tautonyms).
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Question 1c:
Answer:
The aims of classical taxonomy are:
1. Identification: Assigning organisms to known groups based on observable traits.
2. Nomenclature: Establishing standardized naming systems (e.g., binomial nomenclature).
3. Classification: Organizing species into hierarchical categories (e.g., genus, family).
4. Documentation: Recording biodiversity for scientific and conservation purposes.
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Question 1d:
Answer:
John Hutchinson (1884–1972) was a British botanist renowned for his contributions to angiosperm classification. He proposed a phylogenetic system emphasizing evolutionary relationships, notably in *The Families of Flowering Plants*. His work differentiated herbaceous and woody plants, though some classifications were later revised. Hutchinson’s legacy lies in integrating morphology and phylogeny.
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Question 1e:
Answer:
Carl Linnaeus is celebrated in taxonomy for:
1. Introducing binomial nomenclature (Genus + species).
2. Publishing *Systema Naturae*, which laid the foundation for modern classification.
3. Developing a sexual system for plant classification based on reproductive structures.
4. Standardizing taxonomic practices still in use today.
5. Inspiring global biological exploration and documentation.
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Question 1f:
Answer:
Experimental taxonomy employs empirical methods to resolve taxonomic uncertainties. Techniques include:
1. Hybridization experiments to assess reproductive barriers.
2. Cytogenetic studies to analyze chromosome structure and ploidy levels.
3. Ecological trials to observe adaptations under varying conditions.
4. Chemotaxonomy (e.g., analyzing secondary metabolites).
This approach bridges traditional morphology with genetic and ecological data.
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Question 2a:
Answer:
Types of biosystematic relationships between plants include:
1. Genetic relationships (shared DNA sequences).
2. Morphological relationships (structural similarities).
3. Ecological relationships (habitat preferences).
4. Reproductive relationships (cross-compatibility or isolation mechanisms).
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Question 2b:
Answer:
Numerical Phenetics classifies organisms using quantitative analysis of multiple characters (e.g., morphology, biochemistry). Key features:
1. Clustering algorithms group taxa based on overall similarity.
2. Distance matrices quantify differences between taxa.
3. Non-evolutionary: Ignores phylogeny, focusing on phenetic similarity.
4. Criticized for oversimplification but useful in preliminary analyses.
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Question 2c:
Answer:
The six principles of ICBN Division I are:
1. Botanical nomenclature is independent of zoological.
2. Application of binomial names (Genus + specific epithet).
3. Priority of the earliest validly published name.
4. Type method (holotype, lectotype, etc.).
5. Names must be effectively published.
6. Latin diagnosis required for new taxa (pre-2012).
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Question 3a:
Answer:
Preliterate taxonomy involved classifying organisms based on:
1. Utility: Edible, medicinal, or poisonous properties.
2. Morphology: Shape, color, or habitat.
3. Cultural significance: Mythological or symbolic associations.
Examples include indigenous folk taxonomies, such as categorizing plants as “herbs” or “trees.”
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Question 3b:
Answer:
Geographical variation refers to differences in traits across a species’ range due to:
1. Environmental gradients (e.g., temperature, altitude).
2. Genetic drift in isolated populations.
3. Natural selection favoring local adaptations.
Manifestations include:
– Clinal variation (gradual trait changes across a gradient).
– Allopatric speciation (divergence due to geographic barriers).
– Ecotypes (locally adapted subpopulations).
Examples: Bergmann’s rule (body size in mammals), Gloger’s rule (pigmentation in birds).
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Question 4a:
Answer:
Directional selection favors one extreme phenotype, shifting the population’s trait distribution. Characteristics:
1. Common in changing environments (e.g., pesticide resistance in insects).
2. Reduces genetic diversity over time.
3. Example: Peppered moths (*Biston betularia*) shifting to darker forms during industrialization.
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Question 4b:
Answer:
Characters in systematics are traits used to infer relationships:
1. Morphological: Shape, structure (e.g., leaf venation).
2. Molecular: DNA sequences or protein structures.
3. Behavioral: Mating calls, foraging patterns.
4. Ecological: Habitat preferences, pollination strategies.
Characters are analyzed for homology (shared ancestry) vs. homoplasy (convergent evolution).
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Question 5a:
Answer:
Folk taxonomy is traditional classification by non-scientists, using local names and categories based on utility (e.g., “medicinal herbs”) or observable traits (e.g., “water birds”).
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Question 5b:
Answer:
– Post-Linnaeus Taxonomists:
1. Augustin Pyramus de Candolle (plant classification).
2. George Bentham & Joseph Hooker (natural system).
3. Charles Darwin (evolutionary taxonomy).
– Phylogenetic System Taxonomists:
1. Willi Hennig (cladistics).
2. Arthur Cronquist (angiosperm classification).
3. Armen Takhtajan (evolutionary systematics).
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Question 5c:
Answer:
Obstacles in apomixis research:
1. Morphological similarity: Apomictic clones resemble parents, complicating species delimitation.
2. Hybridization: Frequent in apomicts, blurring genetic boundaries.
3. Polyploidy: Common in apomictic taxa, hindering cytogenetic analysis.
4. Limited genetic diversity: Reduces utility of molecular markers.
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Question 6a:
Answer:
Biogeography studies species distribution patterns. Key aspects:
1. Historical biogeography: Impact of continental drift (e.g., Gondwana breakup).
2. Ecological biogeography: Role of climate and habitat.
3. Island biogeography: Species-area relationships and isolation effects (MacArthur & Wilson’s theory).
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Question 6b:
Answer:
Generic names (genus names):
1. Follow binomial nomenclature (e.g., *Panthera leo*).
2. Must be capitalized, italicized, and Latinized.
3. Governed by ICBN rules (priority, typification).
4. Reflect shared traits or honor scientists (e.g., *Darwinia*).
5. Revised based on phylogenetic insights (e.g., splitting *Aster* into multiple genera).