Evolution, Taxonomy, and Plant Anatomy: Key Concepts

Evolutionary Biology: Core Principles

1. What is a fossil? A fossil is the preserved remains of an organism.

2. Natural Selection: Natural selection refers to the adaptation of species in different environments. Only the fittest organisms survive to reproduce.

3. Evolutionary Structures:

• Homologous Structures: Structures that share the same evolutionary origin and arrangement of function.
• Analogous Structures: Body parts that have similar functions but do not share a common evolutionary ancestor.
• Vestigial Structures: A body part that no longer serves its original purpose but was likely useful to an ancestor.

4. Darwin's Theory of Evolution: Darwin's theory posits that each living being adapts to its environment. Observations of tortoises and finches helped him develop this theory. For example, he noticed short-necked tortoises on islands with abundant plants, where stretching their necks wasn't necessary. Conversely, long-necked tortoises lived in different environments. Similarly, finches exhibited different beak shapes depending on their food source.

Taxonomy and Classification of Organisms

5. Taxonomy: Taxonomy is the branch of biology focused on identifying, classifying, and naming organisms. Scientists classify organisms into two primary groups: plants and animals.

• Plants: Described as herbs, shrubs, or trees.
• Animals: Classified based on whether they swim, fly, or walk.

Scientists use scientific names, such as Canis familiaris for the domestic dog.

Binomial Nomenclature: This system uses a combination of Greek and Latin words. "Binomial" means two names, and "nomenclature" means naming.

Domains and Kingdoms

6. Domains and Kingdoms:

• Domain: Bacteria
  • Kingdom: Eubacteria
  • Cell Type: Prokaryotic
  • Cell Structures: Cell walls with peptidoglycan
  • Number: Unicellular
  • Nutrition: Auto-heterotrophic
• Domain: Archaea
  • Kingdom: Archaebacteria
  • Cell Type: Prokaryotic
  • Cell Structures: Cell walls without peptidoglycan
  • Number: Unicellular
  • Nutrition: Auto-heterotrophic
• Domain: Eukarya
  • Protista: Eukaryotic, cell walls of cellulose in some, chloroplasts in some, mostly unicellular, some multicellular, auto-heterotrophic.
  • Fungi: Eukaryotic, cell walls of chitin, mostly multicellular, some unicellular, heterotrophic.
  • Plantae: Eukaryotic, cell walls of cellulose, chloroplasts, multicellular, autotrophic.
  • Animalia: Eukaryotic, no cell walls or chloroplasts, multicellular, heterotrophic.

Plant Kingdom: Diversity and Structures

7. Plant Diversity: Nonvascular plants, ferns, vascular plants, gymnosperms, angiosperms, cones, monocots, dicots, one seed leaves.

8. Plant Anatomy:

Terminal bud, auxiliary bud, flower, 4th node, flower stalk, 3rd node, axil, 2nd node, internode, lateral root or branch, 1st node, petiole, leaf, stem, root, root cap, tap root.