General Biology Final Exam Study Guide: Key Concepts and Topics

Scientific Inquiry and Experimental Design

Independent and Dependent Variables

Understanding variables is essential for designing and interpreting experiments in biology.

• Independent Variable: The factor that is changed or manipulated in an experiment.

• Dependent Variable: The factor that is measured or observed in response to changes in the independent variable.

• Example: In a study testing the effect of light on plant growth, light intensity is the independent variable, and plant height is the dependent variable.

Chemical Foundations of Life

Atoms, Subatomic Particles, and Chemical Bonds

All matter is composed of atoms, which consist of subatomic particles: protons, neutrons, and electrons.

• Atomic Number: Number of protons in an atom.

• Types of Chemical Bonds:

  • Covalent Bonds: Atoms share electrons.

  • Hydrogen Bonds: Weak attractions between partially charged regions of molecules, important in water and biological molecules.

• Acids and Bases: Acids donate protons (H+), bases accept protons. pH measures hydrogen ion concentration.

Properties of Water

Water is vital for life due to its unique properties.

• Cohesion and Adhesion: Water molecules stick to each other and to other surfaces.

• High Specific Heat: Water resists temperature changes.

• Solvent Properties: Water dissolves many substances, facilitating chemical reactions.

Molecules and Macromolecules

Large Biological Molecules

Cells contain four major classes of macromolecules: carbohydrates, lipids, proteins, and nucleic acids.

• Structure and Function: Each type has unique building blocks and functions.

• Dehydration Synthesis and Hydrolysis: Dehydration synthesis joins monomers, hydrolysis breaks them apart.

• Enzymes: Proteins that catalyze biochemical reactions by lowering activation energy.

Cell Structure and Function

Cell Membranes and Transport

Cell membranes regulate the movement of substances in and out of cells.

• Phospholipid Bilayer: Forms the basic structure of cell membranes.

• Selective Permeability: Only certain molecules can pass through the membrane.

• Transport Mechanisms: Includes diffusion, facilitated diffusion, active transport.

Prokaryotic vs. Eukaryotic Cells

Cells are classified as prokaryotic or eukaryotic based on their structure.

• Prokaryotic Cells: Lack a nucleus and membrane-bound organelles (e.g., bacteria).

• Eukaryotic Cells: Have a nucleus and organelles (e.g., plants, animals, fungi).

Metabolism and Energy

Cellular Respiration and Photosynthesis

Cells obtain energy through metabolic pathways.

• Cellular Respiration: Converts glucose and oxygen into ATP, water, and carbon dioxide.

• Photosynthesis: Plants convert light energy, water, and carbon dioxide into glucose and oxygen.

• Equation for Cellular Respiration: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{ATP}$

• Equation for Photosynthesis: $6CO_2 + 6H_2O + \text{light energy} \rightarrow C_6H_{12}O_6 + 6O_2$

Genetics and Inheritance

Mendelian Genetics and Punnett Squares

Genetics explains how traits are inherited from one generation to the next.

• Genotype: Genetic makeup of an organism.

• Phenotype: Observable traits.

• Punnett Squares: Used to predict the probability of offspring genotypes and phenotypes.

• Dominant and Recessive Alleles: Dominant alleles mask recessive alleles in heterozygotes.

• Monohybrid and Dihybrid Crosses: Used to study inheritance of one or two traits.

• Equation for Probability: $\text{Probability} = \frac{\text{Number of desired outcomes}}{\text{Total number of possible outcomes}}$

Non-Mendelian Inheritance

Some traits do not follow simple Mendelian patterns.

• Codominance: Both alleles are expressed equally.

• Incomplete Dominance: Heterozygotes show an intermediate phenotype.

• Multiple Alleles: More than two alleles exist for a gene (e.g., blood types).

Evolution and Natural Selection

Mechanisms of Evolution

Evolution is the change in allele frequencies in a population over time.

• Natural Selection: Individuals with advantageous traits survive and reproduce more successfully.

• Genetic Drift: Random changes in allele frequencies, especially in small populations.

• Gene Flow: Movement of alleles between populations.

• Mutation: Source of genetic variation.

Speciation and Phylogeny

Speciation is the formation of new species, and phylogeny is the evolutionary history of organisms.

• Reproductive Isolation: Prevents gene flow between populations.

• Phylogenetic Trees: Diagrams showing evolutionary relationships.

Classification and Diversity of Life

Major Groups of Organisms

Life is classified into domains and kingdoms based on shared characteristics.

• Domains: Bacteria, Archaea, Eukarya.

• Kingdoms: Protists, Fungi, Plants, Animals.

• Major Animal Phyla: Examples include Chordata, Arthropoda, Mollusca, Nematoda.

Plant and Animal Diversity

Plants and animals have diverse forms and functions adapted to their environments.

• Plant Groups: Mosses, ferns, gymnosperms, angiosperms.

• Animal Groups: Fish, amphibians, reptiles, birds, mammals.

Ecology and Interactions

Population and Community Ecology

Ecology studies interactions among organisms and their environment.

• Population: Group of individuals of the same species in an area.

• Community: All populations in a given area.

• Food Webs: Show energy flow and feeding relationships.

Adaptations and Environmental Impact

Organisms adapt to their environments through structural, physiological, and behavioral changes.

• Examples: Camouflage, migration, hibernation.

• Human Impact: Pollution, habitat destruction, climate change.

Table: Comparison of Prokaryotic and Eukaryotic Cells

Feature	Prokaryotic Cells	Eukaryotic Cells
Nucleus	Absent	Present
Organelles	Absent	Present
Examples	Bacteria, Archaea	Plants, Animals, Fungi, Protists
Size	Small (1-10 μm)	Larger (10-100 μm)

Table: Types of Chemical Bonds

Bond Type	Description	Example
Covalent	Atoms share electrons	Water (H2O)
Hydrogen	Weak attraction between molecules	Between water molecules
Ionic	Transfer of electrons	Salt (NaCl)

Additional info:

• Some topics were expanded for clarity and completeness, including definitions and examples.

• Tables were inferred from key points for comparison and classification.