Chapter 1: Biology

• Biodiversity

  The amount of biological or living diversity per unit area. Includes 3 concepts; species diversity, habitat diversity, and genetic diversity.
• Biological Species Concept


  Groups capable of interbreeding and producing fertile offspring, reproductively isolated from others.
• Morphological Species Concept

  Defined by shared physical traits/characteristics.
• Phylogenetic Species Concept


  Smallest group sharing a common ancestor, highlighting evolutionary lineage.
• Ecological Species Concept


  Defined by unique ecological niches and adaptations.
• Taxonomy 


  The science of naming, describing, and classifying organisms.
• Hybridization

  The cross breeding of two different species, the resulted offspring will be infertile and will lack the successful traits to survive.
• Individual Variability


  Differences in traits among individuals within a population.
• Sources of Variability

  1.Genetic differences due to mutations, gene combinations

  2.Environmental influences such as climate, food, and lifestyle

  3.Interaction between genes and environment
• Species


  All organisms capable of breeding freely with each other under natural conditions.
• Variation Over Time

  Evolutionary changes in species traits, historical shifts in climate and ecosystems, and cultural and societal evolution.
• Variation Over Space


  Geographic differences in species, climate, and topography (description of the surface features of a place). Biodiversity patterns, cultural diversity, and linguistic variations across regions.
• Components of Biodiversity

  Ecosystem Diversity: variety of habitats, biomes, and ecological processes.

  Species Diversity: variety among species in an ecosystem.

  Genetic Diversity: variety of genes within species.
• Autotroph


  Make their own food through photosynthesis (for example, plants).
• Heterotroph


  Consume food made by autotrophs (for example, a cow eats grass which is an autotroph).
• Evolutionary Change


  Physical and behavioural changes that occur in entire populations of a species over time.
• Human Caused Threats to Biodiversity

  Pollution, over exploitation of natural resources (overfishing, overhunting, etc.), climate change, and habitat destruction.
• Biological Classification 


  A system for organizing the vast diversity of life on Earth by grouping organisms into hierarchical categories based on shared characteristics and evolutionary relationships.
• Why Classify Organisms?

  Facilitates scientific communication and research, essential for identifying, studying, and conserving species.
• 8 Taxonomic Categories

  1.Domain

  2.Kingdom

  3.Phylum

  4.Class

  5.Order

  6.Family

  7.Genus

  8.Species
• Carl Linnaeus


  Swedish naturalist who is considered the “father” of taxonomy. He established the naming system binomial nomenclature. He grouped living things into categories called genera based off of shared characteristics.
• Binomial Nomenclature


  A system of naming species by assigning a genus name followed by a specific name. For example, humans are called Homo sapiens, the briar rose is called Rosa canina, etc.
• Dichotomous Keys


  A series of branching, two-part statements used to identify organisms or objects. Large set of items is broken down into smaller subsets, leading to smallest available classification unit
• Traditional vs Modern Classification Systems

  Traditional: Groupings based on specific similarities and characteristics among organisms, binomial nomenclature.

  Modern (phylogenetic): Can easily trace back common ancestors between species, can easily determine how species are connected to each other.
• Evolution 


  The scientific theory that describes changes in species over time and their shared ancestry.
• Phylogeny


  The study of evolutionary relatedness between, and among species.
• Phylogenetic Tree


  Illustrates how different species are related to each other through common ancestors. Organisms most closely related should share the most recent common ancestor (highest branch on tree) and organisms more distantly related share the oldest common ancestor (lowest branch on tree).
• Phylogenetic Tree vs Cladogram

  Phylogenetic tree: Highlights where lineages diverge and how they have changed over time

  Cladogram: Show how different species are related based on shared features
• Branch


  Represent different species that have evolved from a common ancestor.
• Node


  Signify the common ancestors, points at where lineages diverge.
• Root

  Represent the most ancient common ancestor from which all organisms on the tree descended.
• Clade

  A group of organisms that includes an ancestor and all its descendants, living and extinct. Clades can be part of larger clades.
• 3 Domains of Life

  Bacteria, archaea, and eukaryotes
• 6 Kingdoms of Life

  1.Bacteria

  2.Archaea

  3.Protista

  4.Fungi

  5.Plantae

  6.Animalia
• Prokaryotic vs Eukaryotic

  Prokaryotic: No nucleus, do not undergo mitosis, no organelles, archaea and bacteria

  Eukaryotic: Fully nucleated cells, nucleolus contains ribosomal DNA, undergo mitosis, consist of organelles, formed by a combination of archaea and bacteria
• Bacteria vs Archaea

  Bacteria: Have peptidoglycan (provides structural support) in their cell wall, genes are different from eukarya

  Archaea: Do not have peptidoglycan in their cell wall, genes are more similar to eukarya
• Cross Breeding


  Mating from different breeds or genetic backgrounds within the same species.
• Interbreeding


  Mating from different populations or species.
• Domain


  The highest taxonomic level
• 3 Types of Diversity

  Genetic: Variety of genes within species

  Species: Variety among species in an ecosystem

  Structural: Range of physical shapes and sizes within a habitat or ecosystem