General Biology - The Science of Life (BIOL 1406)

Course Overview

• General Biology (BIOL 1406) - introductory survey of life sciences
• Instructor: Dr. Marilynn Kish-Molina
• Emphasis on understanding life from molecular to global scales, using standard biology concepts, terminology, and frameworks

What is Biology?

• Biology is the study of life

Publisher/Source Notes

• Some slides show publishers and web addresses (e.g., Benjamin Cummings); these indicate typical textbook/teaching aids used in BIOL 1406

Levels of Organization (Hierarchy of Living Systems)

• Atomic level: atom (example: hydrogen, H)
• Molecular level: molecule (example: water, H2O)
• Organelle level: organelle (example: nucleus)
• Cellular level: cell (example: neuron)
• Tissue level: tissue (example: nervous tissue)
• Organ level: organ (example: brain)
• Organ system level: organ system (example: nervous system)
• Organism level: organism (example: sea lion)
• Population level: population (example: colony)
• Community level: community (example: forest)
• Ecosystem level: ecosystem (example: coastal ecosystem)
• Biosphere level: biosphere (Earth)
• Context note: these levels illustrate how life is organized from simple parts to complex systems and their interactions

Periodic Table of the Elements (Key Concepts)

• The periodic table organizes elements by atomic number and properties
• Visuals typically show groups such as noble/inert gases (inert column)
• Includes representations of alkali/alkaline earth metals, transition metals, halogens, noble gases, etc.
• Special series noted: Lanthanide series and Actinide series (as separate blocks) in many tables
• Importance: elemental properties influence chemical behavior of molecules, including biomolecules

Information Transfer: DNA

• DNA transmits genetic information from one generation to the next
• DNA makes up genes
• DNA codes for proteins (genetic expression governs phenotype)

Cell Types: Prokaryotic vs Eukaryotic

• Prokaryotic cells
  • Types: Bacteria and Archaea
  • Characteristic: do not have a nucleus
• Eukaryotic cells
  • Types: Fungi, Protists, Plants, Animals
  • Characteristic: have a nucleus

Cellular Organelles and Differences: Animal vs. Plant Cells

• Shared organelles (both cell types)
  • Nucleus (contains DNA organized as chromatin; nucleolus inside; nuclear envelope; nuclear pores)
  • Plasma membrane
  • Cytoplasm
  • Rough Endoplasmic Reticulum (RER) with ribosomes
  • Smooth Endoplasmic Reticulum (SER)
  • Ribosomes (free and attached to RER)
  • Golgi apparatus
  • Mitochondrion
  • Vesicles
  • Lysosome
  • Peroxisome
  • Cytoskeletal elements (microtubules, microfilaments, intermediate filaments)
• Plant cell–specific features
  • Chloroplasts (photosynthesis)
  • Central vacuole (tonoplast membrane)
  • Cell wall (rigid structure outside plasma membrane)
  • Plasmodesmata (intercellular channels)
• Animal cell features and general organization
  • Often more scattered vesicles and organelles; lack chloroplasts and cell wall

Nucleus, Nucleolus, Chromatin, and Macromolecules

• Nucleus houses chromatin (DNA + proteins)
• Nucleolus is a site within the nucleus where ribosomal RNA (rRNA) synthesis occurs
• Nuclear envelope encases the nucleus; contains nuclear pores for transport
• Macromolecules: DNA, RNA, proteins, etc.

Ecological and Biological Organization (Nomenclature and Relationships)

• Nucleus → Organism → Organ System → Organ → Tissue → Cell → Organelle → Macromolecule → Molecule
• Ecological levels include Population, Community, Ecosystem, and Biosphere
• Population: all individuals of a single species in a defined area
• Community: many populations of different species interacting in a shared environment
• Ecosystem: all biotic (living) and abiotic (nonliving) factors in an area, including energy flow and nutrient cycles
• Biosphere: all Earth's ecosystems

Population and Community Definitions (from slides)

• Population: all the members of one species in a defined area
• Community: many populations of different species inhabiting a common environment and interacting with one another

Ecosystem Components and Energy Flow (Key Concepts)

• Producers: plants (terrestrial) and phytoplankton (aquatic)
• Primary consumers: herbivores that eat producers
• Secondary consumers: carnivores/omnivores that eat primary consumers
• Tertiary consumers: higher-level predators
• Decomposers: organisms that break down dead matter and recycle nutrients
• Biotic vs. Abiotic factors: living vs nonliving components of the environment
• Dissolved chemicals and sediments are part of abiotic factors in ecosystems

Biosphere and Biomes

• Biosphere: all of Earth's ecosystems
• Biome: worldwide, climate-driven complexes of communities characterized by climax vegetation

Defining Life and Its Complexity

• It is difficult to define life due to tremendous variety and complexity across organisms

Characteristics of Living Organisms

• Movement: the inherent ability to change place or position
• Irritability (responsiveness): ability to respond to stimuli
• Metabolism: total of all chemical reactions in an organism
• Homeostasis: body's ability to regulate and balance internal environment
• Growth: increase in size and/or number of cells
• Development: changes during an organism’s lifetime
• Reproduction: production of new organisms to maintain continuity of life
• Adaptability: ability to adjust to environmental changes
• Evolution/Adaptations: populations evolve and adapt; adaptations enhance survival

Metabolism, Homeostasis, Growth, Development, Reproduction, and Adaptation in Context

• Metabolic processes sustain energy production and biomolecule synthesis
• Homeostasis maintains stable internal conditions (temperature, pH, glucose, etc.)
• Growth vs development: growth refers to size/cell number increase; development refers to maturation and progression through life stages
• Reproduction ensures continuity of species; can be asexual (low genetic variability) or sexual (high genetic variability)
• Adaptability and evolution: genetic changes that improve survival in changing environments

Taxonomy and Binomial Nomenclature

• Taxonomy: study of the classification of living organisms
• Binomial nomenclature: system naming organisms using two Latin names: genus and species
• Binomial name format: Genus is capitalized; species epithet is lowercase; both italicized or underlined
• Example: Homo sapiens (scientific name); common name: human

Binomial Nomenclature: Example and Format

• Binomial format: Genus (capitalized) + species epithet (lowercase)
• Example in slides: Callinectes sapidus (scientific name for the blue crab)
• Order of printing: Genus species (in italics or underlined when handwritten)

Latin Name Meanings

• Latin name parts describe features or characteristics of the organism
• Example: Ursus horribilis (Latin for a bear with a horrible reputation) illustrating how genus and species names convey traits

Taxonomic Classification (Hierarchy)

• Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species

Taxonomic Classification: Examples

• Human (Homo sapiens):
  • Domain: Eukarya
  • Kingdom: Animalia
  • Phylum: Chordata
  • Subphylum: Vertebrata
  • Class: Mammalia
  • Order: Primates
  • Family: Hominidae
  • Genus: Homo
  • Species: sapiens
• White Oak (Quercus alba):
  • Domain: Eukarya
  • Kingdom: Plantae
  • Phylum: Anthophyta
  • Subphylum: None listed in slide
  • Class: Eudicotyledons
  • Order: Fagales
  • Family: Fagaceae
  • Genus: Quercus
  • Species: alba

Species Concept

• Species: a group of similar organisms capable of interbreeding and producing fertile offspring

Three Domains and Six Kingdoms

• Three Domains: Bacteria, Archaea, Eukarya
• Six Kingdoms within the three domains (under Eukarya, Bacteria, and Archaea): Protista, Plantae, Animalia, Fungi, Bacteria, Archaea
• Example notes from slides:
  • Bacillus anthracis (domain Bacteria) – causes anthrax
  • Methanosarcina mazei (domain Archaea) – methane producers
  • Tetrahyemna (protozoan in Protista)
  • Lions (Panthera leo) as an example of animal diversity within Animalia
  • Amanita muscaria (fly agaric mushroom) in Fungi; poisonous and can cause delirium and sweating

The Scientific Method (Overview)

• Steps:
  • Observation
  • Question
  • Hypothesis – a tentative, testable explanation; should be predictive (often framed as if-then)
  • Perform experiments (tests the hypothesis)
  • Collect and analyze data
  • Conclusion – evaluate whether the data support the hypothesis

What is a Hypothesis?

• A tentative scientific explanation that must be tested experimentally

What is a Theory?

• A theory has a greater breadth of evidence than a hypothesis; explains the natural world based on multiple hypotheses, observations, and experiments

What is a Scientific Law (as described in slides)?

• A statement of order found to be invariable under the same conditions; a hypothesis that has been tested many times and still supports the underlying idea

Good Experimental Design (Key Concepts)

• Control Group vs. Experimental Group
• Placebo vs. Treatment
• Bias
• Sample Size
• Blind Study
• Double-Blind Study

Additional Notes and Cross-References

• Definitions and examples from the slides can be connected to foundational principles in biology, chemistry, and ecology
• Real-world relevance includes understanding how genetic information is inherited, how organisms interact in ecosystems, and how scientific conclusions are drawn from controlled experiments
• Ethical considerations in experimental design (e.g., minimizing harm, ensuring informed consent in applicable studies) are implied by the emphasis on controls, bias reduction, and blinding