Biology Chapter 1 Review - Flashcards

Scientific Method

• A recursive process for discovering and validating new knowledge in biology

• Steps (as described):

  • Make observations

  • Form a hypothesis (a testable model)

  • Design and conduct experiments to test the hypothesis

  • Collect and analyze data (evidence)

  • Accept, reject, or revise the hypothesis and retest

• Reasoning types

  • Deductive reasoning: general → specific; conclusions must follow from premises if the premises are true

  • Example: Tarantulas have 8 legs (specific observation leads to a general expectation about tarantulas’ anatomy)

  • Limitations: not always accurate due to limited data or resources

  • Inductive reasoning: specific observations → generalization; conclusions are probabilistic

  • Example: Observing several species with similar traits may lead to a generalization about that trait in related species

• Hypothesis

  • A testable model that can be supported or refuted by data

  • Can be revised or replaced based on evidence

  • Not guaranteed to be true; most hypotheses will be revised with new data

• Experimental design

  • An experiment tests a hypothesis by manipulating a variable and observing effects

  • Key components:

  • Treatment group: receives the experimental manipulation

  • Control group: does not receive the manipulation

  • Placebo effect: needs to be controlled to avoid bias

  • Blinding: keeping researchers or participants unaware of which group is which to prevent bias

• Important outcomes

  • From data, you obtain evidence that supports or rejects the hypothesis

  • If rejected, revise the hypothesis and retest

• Experimental integrity

  • All groups should receive the same treatments except for the manipulated variable

  • Proper controls and randomization are essential to avoid bias

• The scientific process is iterative and self-correcting

Biology Chapter 1: Core Concepts

• Biology as the study of life using the scientific method

• Recursiveness of science

  • More observations lead to more testable models

  • Theories emerge from a body of evidence and may be refined over time

• Theory vs Law in biology

  • Theory: a well-supported explanation that links a large body of observations

  • Law: a statement describing consistent relationships under specified conditions (often expressed as a rule or equation in physics/chemistry; biology tends to emphasize theories and laws as explanations rather than absolute certainties)

  • A hypothesis is a starting point; a theory is a culmination of evidence

• Supernatural explanations

  • Considered outside the bounds of science; cannot be proven or disproven by scientific means

• Emergent properties and organization

  • Emergent properties: new features that arise when smaller units interact (properties not present in individual parts)

  • Systems biology: study of biological systems by analyzing interactions among their parts (networks and feedback)

• Evolution

  • The process of change that has transformed life on Earth via adaptation to environments

  • The idea that “nothing makes sense except in the light of evolution” highlights its fundamental role in biology

• Information and interactions

  • Information: expression and transmission of genetic material (DNA/RNA) across generations

  • Interactions: components of biological hierarchies interact to ensure integrated function

• Energy and transformation

  • Life requires energy to perform work, maintain order, grow, and reproduce

  • Energy transformations (metabolism) enable cellular activities

• Organization and hierarchy

  • Biological systems are organized into levels that show increasing complexity and new properties at each level

Biological Organization: Hierarchy of Life

• From most inclusive to least inclusive:
  1) Biosphere – all life on Earth and all places where life exists
  2) Ecosystems – all living things in a particular area plus nonliving components with which life interacts
  3) Communities – all populations of organisms in a given ecosystem
  4) Populations – all individuals of a species in a defined area that interbreed
  5) Organisms – individual living things
  6) Organs – body parts composed of multiple tissues with specific functions
  7) Tissues – groups of cells performing specialized functions
  8) Cells – fundamental unit of life; all living things are made of cells
  9) Organelles – functional components within cells
  10) Molecules – chemical structures consisting of two or more atoms
  11) Atoms – basic units of chemical elements

• Notes

  • Biological organization shows how simple components organize into complex systems

  • The saying "All living things are made from cells" underpins cellular biology and life processes

Naming Living Things: Taxonomy and Binomial Nomenclature

• Taxonomy: science of naming and classifying living organisms

• Species: basic unit of classification; a population that interbreeds and has genetic continuity

• Binomial nomenclature rules (Linnaeus system)

  • Binomial name = Genus + specific epithet

  • Genus is always capitalized; specific epithet is never capitalized

  • Genus and specific epithet are written together; in typing, the binomial name is italicized; in handwriting, it is underlined

  • Example: Homo sapiens

• Classification: hierarchical arrangement in order of rank

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

  • Mnemonic (widely used): Dear King Philip Came Over For Great Sex

• The widely accepted system today includes 3 domains and 6 kingdoms

  • Domains: Archaea, Bacteria (prokaryotic domains), Eukarya

  • Archaea: often found in extreme environments; methanogens, extreme halophiles, and extreme thermophiles

  • Bacteria: a diverse group including E. coli, Mycobacterium tuberculosis, etc.

  • Eukarya: organisms with a discrete nucleus; includes four kingdoms listed below

• Kingdoms (within Eukarya)

  • Protista: organisms with nuclei; some have cell walls; can be single-celled or multicellular; includes protozoa, water molds, slime molds

  • Plantae: multicellular; cellulose cell walls; many are photosynthetic with chlorophyll

  • Fungi: nuclei; multicellular (mostly); cell walls contain chitin; decomposers (molds, yeasts, mushrooms)

  • Animalia: multicellular; must eat other organisms; no cell walls; usually motile; have organs and organ systems

Characteristics of Living Organisms (IV)

• Cells: basic structural and functional unit of life

  • Capable of growth and development; cells bound by a membrane

  • Unicellular vs. Multicellular

• Growth and Development

  • Growth: increase in size via more cells or larger cells

  • Development: changes in cell roles during the life cycle

• Metabolism and Homeostasis

  • Metabolism: chemical processes for growth, repair, energy use, and transformations

  • Homeostasis: tendency to maintain a relatively constant internal environment

• Responding to Stimuli

  • Organisms respond to physical or chemical changes in their internal or external environment

• Reproduction

  • Essential for the continuation of life; fitness measures reproductive success

  • Fitness: a quantitative measure of reproductive success

  • Asexual reproduction: copying via cell division; no fusion of gametes

  • Sexual reproduction: involves gametes (egg and sperm); fusion yields a zygote

• DNA and Heredity

  • DNA stores genetic information that must be transferred from one generation to the next

  • Genes are the units of heredity

• Hormonal and Signaling Communication

  • Hormones: chemical signals used for intercellular signaling

  • Nerve impulses and other signaling mechanisms transmit information

• Energy Use and Movement

  • Life requires energy from nutrients to build new components and maintain systems

  • Movement can refer to the movement of the cell or the transport of materials across membranes

• Interactions and Defense

  • Organisms engage in symbiotic relationships and interact with other organisms

  • Defense against pathogens is a key survival function

• Autotrophs and Heterotrophs

  • Autotrophs ( Producers ): make their own food (e.g., through photosynthesis)

  • Heterotrophs ( Consumers ): obtain energy by eating other organisms

  • Decomposers: obtain energy by breaking down waste products, byproducts, and dead bodies; typically bacteria or fungi

  • Energy flow: producers capture energy, which flows through consumers and decomposers in ecosystems

Autotrophs, Heterotrophs, and Ecological Roles

• Autotrophs (Producers)

  • Make their own organic materials from inorganic sources (e.g., photosynthesis in plants and algae)

  • Primary source of energy for most ecosystems

• Consumers (Heterotrophs)

  • Obtain energy by consuming other organisms

  • Include herbivores, carnivores, omnivores, and detritivores

• Decomposers

  • Break down dead material and waste products, recycling nutrients back into ecosystems

  • Commonly, bacteria and fungi

Quick Reference: Formulas and Key Terms

• Binomial nomenclature rule (format):

  • ext{Binomial name} = ext{Genus} imes ext{specific epithet}

  • Genus is capitalized; specific epithet is not; name is italicized when typed, or underlined when handwritten

• Domains and Kingdoms

  • 3 ext{ domains}
    ightarrow ext{Archaea, Bacteria, Eukarya}

  • 6 ext{ kingdoms}
    ightarrow ext{Protista, Plantae, Fungi, Animalia, (and two others within Eukarya as context)}

• Fitness

  • ext{Fitness} = ext{reproductive success (quantitative)}

• Evolutionary principle

  • Evolution explains the diversity of life and its adaptations to environments

• Emergent properties (conceptual)

  • Properties that arise from the interactions of parts at a higher level, not predictable from the parts alone

Connections to Foundational Principles and Real-World Relevance

• The scientific method underpins evidence-based research in biology and medicine

• Understanding hierarchy and organization helps in fields ranging from ecology to biomedical sciences

• Taxonomy and binomial nomenclature enable clear communication about species across languages and disciplines

• Evolution provides a unifying framework for understanding both biology and medicine

• Energy flow and metabolism underpin all cellular processes, affecting health, agriculture, and environmental science

• Recognizing producers, consumers, and decomposers is essential for ecosystem management and conservation

• Emergent properties and systems biology inform how complex diseases might arise from interactions among cellular components

• Ethical and philosophical implications include the limits of reductionism, the nature of scientific explanations, and the role of science in society