bio exam 1

Chapter 1: Science and the Question of Our Origins

  • Earth's Age: 4.5 billion years old

  • Life's Age: 3.5 billion years old

  • Science: Method of gaining knowledge via empirical processes and resulting body of knowledge (tools + discoveries).

    • Empiricism: External testing of ideas.

    • Data: Observations gathered through empirical processes.

  • Biology: A science branch focused on investigations of life.

  • Hypothesis: A possible explanation for observations.

  • Experiment: A test conducted to validate hypotheses.

  • Inductive Reasoning: Conclusion based on likely outcomes, often used to formulate hypotheses but not guaranteed to be correct.

  • Parsimonious: Simple and plausible explanations are preferable.

  • Deductive Reasoning: Draws conclusions that necessarily follow from premises; if premises are true, conclusions are true.

  • Scientific Theories: Frameworks encompassing a broad set of facts, while Facts: Acceptable truths.

  • Life: Biochemical systems capable of growth, response to stimuli, and reproduction.

    • Organism: A single living entity; smallest unit of life is the cell.

    • Energy and Information Flow: Fundamental aspects of life.

    • DNA: Carries genetic information and encodes life’s blueprint; composed of two nucleotide strands.

  • Phenotypes: Physical traits determined by the DNA sequence.

  • Gene: The DNA sequence coding for a characteristic; different versions are alleles (resulting from mutations).

  • Evolution: The process explaining the diversity of species (originated from Charles Darwin's theories).

  • Descent with Modification: New species arise from ancestral species through generational changes; evolution occurs at the population level.

Chapter 2: Population Dynamics and Natural Selection

  • Population: Group of species members in the same area at the same time.

    • Individuals with advantageous traits survive and reproduce.

    • Natural Selection:

      1. Variation within a species.

      2. Inheritance of variations.

      3. Selection of specific variations.

  • Adaptation: Evolution that enhances fit between organisms and environments.

    • Onset driven by environmental factors, mate preferences (sexual selection), or human intervention (artificial selection).

  • Convergent Evolution: Different species developing similar adaptations due to shared selective pressures.

  • Mutations: New variations in DNA sequences that create new phenotypes; mutations are often random.

  • Genetic Drift: Allele frequency shifts due to random chance; maintains diversity against extinction.

  • Genetic Recombination: Mixing of DNA during sexual reproduction; increases genetic variability.

  • Vertical Gene Transfer: Passing of genes via parents to offspring.

  • Horizontal Gene Transfer: Transfer of genes between organisms of the same or different species.

Chapter 3: Evolutionary Mechanisms

  • Transposon Movement: “Jumping genes” within genomes.

  • Prokaryotes: Simple organisms lacking a nucleus and membrane-bound organelles.

    • Reproduce asexually.

  • Eukaryotes: Complex organisms with organelles and potential for sexual reproduction.

  • Rate of Evolution: Influenced by reproduction frequency, mutation likelihood, and selection strength.

  • Conserved Genes: Remain unchanged through time, crucial for basic organism functions.

  • Punctuated Equilibrium: Periods of stability are interrupted by rapid evolutionary changes.

  • Gradualism: Slow, steady evolutionary changes.

  • Abiogenesis: Origin of life from non-life, possibly through hydrothermal vents; involves several steps such as forming membranes, concentrating life molecules, and creating self-replicating biomolecules (like RNA).

  • Protocells: Primitive precursors to modern cells.

Chapter 4: Speciation and Phylogeny

  • Speciation: Processes through which new species arise from populations.

  • Phylogeny: Ancestral relationships among species.

  • Evolution: Change in allele frequency over time; influenced by factors that increase or decrease diversity.

  • Nonrandom Assortative Mating: Preferences in mating choices affecting genetic diversity.

  • Bottleneck Effect: Loss of genetic diversity due to reduced population size.

  • Founder Effect: Loss of diversity when a small colonizing group establishes a new population.

  • Hardy-Weinberg Equation: A method to detect shifts in population genetics.

  • Gene Flow: The transfer of genetic material between populations.

  • Speciation Barriers: Prezygotic (before fertilization) and postzygotic (after fertilization) mechanisms that affect reproductive success.

  • Allopatric vs. Sympatric Speciation: Geographic vs. genetic isolation leading to new species evolution.

Chapter 5: Evolutionary Dynamics and Selection

  • Quantitative Characters: Traits with a continuous distribution among population members.

  • Selection Types:

    • Directional Selection: Favors one extreme trait leading to shifts in population mean.

    • Stabilizing Selection: Favors intermediate traits, suppressing extremes.

    • Disruptive Selection: Favors extreme traits creating two contrasting phenotypes.

  • Adaptive Radiation: Rapid evolution from a common ancestor to fill various niches.

  • Morphology: Study of body shapes and structures among organisms.

  • Phylogenetics: Analyzes evolutionary relationships and constructs phylogenetic trees.

  • Monophyletic Groups: Include a common ancestor and all its descendants.

  • Principle of Parsimony: Seek the simplest explanation with the least evolutionary leaps.

Chapter 6: Radiometric Dating and Evolutionary Timelines

  • Radiometric Dating: Technique based on radioactive decay rates.

  • Isotopes and Radioisotopes: Variants of elements with unstable nuclei aiding in dating fossils.

  • Molecular Clock: Estimates time since divergence based on mutation rates in DNA and its applications in creating phylogenetic trees.

  • Conserved DNA: Critical sequences for organism functions; mutation-resistant over time.

Chapter 7: Biological Systematics

  • Biological Systematics: Discipline focused on the organization of life through taxonomy, classification, and phylogeny.

  • Five Kingdoms of Life:

    1. Plantae

    2. Animalia

    3. Fungi

    4. Protista

    5. Monera

  • Three Domains:

    1. Bacteria

    2. Archaea

    3. Eukarya

  • Endosymbiotic Theory: Explains the origin of organelles like mitochondria and chloroplasts through symbiotic relationships.

  • Primary vs. Secondary Endosymbiosis: Photosynthesis integration events between different organisms.

  • Nitrogen Fixation: Process to convert atmospheric nitrogen to usable forms for organisms.

Chapter 8: Diversity of Life and Groups

  • Plant Groups: Classification from nonvascular to specialized seed-producing species.

  • Fungal Groups: Division into formal (monophyletic) and informal (not monophyletic) categories based on characteristics.

  • Animal Groups: Categorization based on symmetry and phylogenetic relationships including asymmetrical, radial, and bilateral groups.

Conclusion

  • This compilation illustrates how life evolved, adapted, and diversified through complex interactions within and between species across vast timescales.