General Biology Study Guide: Chapters 1, 26, 27, 28

Chapters Covered: 1, 26, 27, 28

This study guide summarizes key concepts and terms from the lecture slides for General Biology, focusing on foundational topics, biological diversity, prokaryotes, and protists. Students should understand all terms defined in lectures and be able to apply concepts to homework and exam questions.

Chapter 1: Introduction to Biology

Biological Hierarchy

The biological hierarchy organizes living things from the simplest to the most complex levels.

• Levels: Atom → Molecule → Organelle → Cell → Tissue → Organ → Organ System → Organism → Population → Community → Ecosystem → Biosphere

• Definitions: Know the definition and examples of each level.

• Example: A human is an organism; the heart is an organ; cardiac tissue is a tissue.

Overview of Scientific Method

The scientific method is a systematic approach to inquiry in biology.

• Steps: Observation, Question, Hypothesis, Experiment, Data Collection, Analysis, Conclusion

• Terms: Types of inquiry, limitations, requirements, and kinds of hypotheses

• Example: Testing the effect of sunlight on plant growth

Darwinian Evolution

Darwinian evolution explains the diversity of life through natural selection and genetic variation.

• Darwin's Observations: Variation exists in populations; more offspring are produced than survive; traits are inherited.

• Driving Forces: Natural selection, genetic drift, mutation, gene flow

• Example: Finches on the Galápagos Islands adapting beak shapes to food sources

Mouse Video

Application of evolutionary concepts to real-world examples.

• Key Point: Be able to answer questions about the Mouse video watched in class (link provided in notes).

Chapter 26: Diversity and Systematics

Diversity of Life

Biologists classify and study the diversity of living organisms.

• Known Species vs. Actual Number: There are millions of species, but only a fraction are described.

• What Defines Life? Organization, metabolism, growth, adaptation, response to stimuli, reproduction

Systematics

Systematics is the study of the diversity and relationships among organisms.

• Domains of Life: Bacteria, Archaea, Eukarya

• Characteristics: Know features of each domain

Classification and Nomenclature

Classification organizes organisms into groups; nomenclature provides names.

• Binomial Nomenclature: Two-part scientific names (Genus species), e.g., Homo sapiens

• Inventor: Carl Linnaeus

Phylogeny

Phylogeny is the evolutionary history and relationships among species.

• Branch Points: Indicate common ancestors

• Monophyletic, Polyphyletic, Paraphyletic: Types of groups in phylogenetic trees

• Diagram Interpretation: Be able to read and interpret phylogenetic trees

Homology vs. Analogy

Homology refers to similarity due to shared ancestry; analogy is similarity due to convergent evolution.

• Examples: Forelimbs of mammals (homology); wings of birds and insects (analogy)

• Convergent vs. Divergent Evolution: Convergent produces analogous traits; divergent produces homologous traits

Phylogenetic Hypotheses

Phylogenetic hypotheses are based on morphological, molecular, and genetic data.

• Key Point: Know what data phylogenetic trees are based on

Chapter 27: Prokaryotes and Archaea

Differences Between Prokaryotes and Eukaryotes

Prokaryotes lack a nucleus and membrane-bound organelles; eukaryotes have both.

• Prokaryotes: Bacteria and Archaea

• Eukaryotes: Plants, animals, fungi, protists

Bacteria vs. Archaea

Bacteria and Archaea are both prokaryotes but differ in cell structure and environment.

• Unique Features: Archaea have distinct membrane lipids and can live in extreme environments

• Adaptations: Thermophiles, halophiles, methanogens

Bacterial Diversity and Identification

Bacteria vary in shape, arrangement, and metabolic capabilities.

• Shapes: Cocci (spherical), Bacilli (rod-shaped), Spirilla (spiral)

• Arrangements: Chains, clusters, pairs

• Gram Staining: Differentiates bacteria by cell wall structure

Bacterial Cell Structure

Bacterial cells have unique structures that aid in survival and reproduction.

• Parts: Cell wall, plasma membrane, ribosomes, nucleoid, flagella, pili

Bacterial Reproduction and Genetic Recombination

Bacteria reproduce asexually by binary fission and can exchange genes by recombination.

• Binary Fission: Simple cell division

• Genetic Recombination: Transformation, transduction, conjugation

Symbiosis and Metabolism

Bacteria interact with other organisms and have diverse metabolic pathways.

• Symbiosis: Mutualism, commensalism, parasitism

• Energy Acquisition: Photosynthesis, chemosynthesis, heterotrophy

Pathogenic Bacteria

Some bacteria cause disease; others are beneficial.

• Gram Positive vs. Gram Negative: Differences in cell wall structure

• Endotoxins vs. Exotoxins: Types of bacterial toxins

• Examples: Escherichia coli (E. coli), Streptococcus

Beneficial Uses of Bacteria

Bacteria play important roles in ecosystems and human health.

• Examples: Nitrogen fixation, decomposition, probiotics

Chapter 28: Protists

Defining Protists

Protists are a diverse group of mostly unicellular eukaryotes.

• Polyphyletic Group: Protists do not form a single evolutionary lineage

• Roles: Symbionts, parasites

• Examples: Amoeba, Paramecium, Plasmodium

Protist Nutritional Diversity

Protists exhibit a wide range of nutritional strategies.

• Autotrophs: Photosynthetic protists (e.g., algae)

• Heterotrophs: Ingest or absorb food

• Mixotrophs: Combine photosynthesis and heterotrophy

Complexity of Protists

Protists are considered complex due to their diverse life cycles and cellular structures.

• Life Cycles: Alternation of generations, sexual and asexual reproduction

• Morphological Features: Flagella, cilia, pseudopodia

Endosymbiotic Theory

The endosymbiotic theory explains the origin of mitochondria and chloroplasts in eukaryotes.

• Evidence: Double membranes, own DNA, similarities to prokaryotes

• Key Point: Know evidence supporting the theory

Survey of Protists

Protists are classified into major supergroups based on genetic and morphological data.

• Supergroups: Excavata, SAR, Archaeplastida, Unikonta

• Features: Know key features and examples of each

• Life Cycles: Understand cycles discussed in class

Ecological Significance of Protists

Protists play vital roles in aquatic ecosystems and as pathogens.

• Roles: Primary producers, decomposers, disease agents

• Examples: Plasmodium (malaria), Trypanosoma (sleeping sickness)

Additional info:

• Students should focus on terms and concepts defined in lecture slides and homework questions.

• Be familiar with examples and applications discussed in class, especially those highlighted in homework.