General Biology Final Exam Study Guide (Chapters 1-7, 9-10, 12-17)

Cumulative Portion

Unifying Themes of Biology

Biology is the study of life, and several themes unify its diverse fields.

• Organization: Life is organized from molecules to biosphere.

• Information: Genetic information is stored in DNA.

• Energy and Matter: Life requires energy transfer and transformation.

• Interactions: Organisms interact with each other and their environment.

• Evolution: Populations evolve over time through natural selection.

Domains of Life

All living organisms are classified into three domains:

• Bacteria: Prokaryotic, unicellular organisms.

• Archaea: Prokaryotic, often extremophiles.

• Eukarya: Eukaryotic organisms, including plants, animals, fungi, and protists.

Natural Selection and Evolution

Natural selection is the process by which organisms better adapted to their environment tend to survive and produce more offspring. Evolution is the change in the genetic composition of a population over generations.

• Example: Darwin's finches adapted beak shapes to different food sources.

Atoms, Elements, and Chemical Bonds

Atoms are the basic units of matter, composed of protons, neutrons, and electrons. Elements are substances consisting of one type of atom. Chemical bonds include:

• Covalent bonds: Atoms share electrons.

• Ionic bonds: Atoms transfer electrons, forming charged ions.

• Polar vs. Nonpolar covalent bonds: Polar bonds have unequal sharing of electrons; nonpolar bonds have equal sharing.

Water Properties and Temperature Moderation

Water's polarity allows it to form hydrogen bonds, giving it unique properties:

• Cohesion and adhesion

• High specific heat: Moderates temperature

• Solvent abilities: Dissolves many substances

Isomers

Isomers are compounds with the same molecular formula but different structures.

• Structural isomers: Differ in covalent arrangement.

• Cis-trans isomers: Differ in spatial arrangement around double bonds.

• Enantiomers: Mirror images of each other.

Macromolecules

Four major classes:

• Carbohydrates

• Lipids

• Proteins

• Nucleic acids

Cell Structure

Cells are the basic units of life. Eukaryotic cells have membrane-bound organelles; prokaryotic cells do not.

• Cytoskeleton: Provides structure and facilitates movement.

• Extracellular matrix: Supports and regulates cell behavior.

Cellular Respiration and Photosynthesis

Cells obtain energy through:

• Cellular respiration: Converts glucose to ATP.

• Photosynthesis: Converts light energy to chemical energy in plants.

Stages of Cellular Respiration:

• Glycolysis

• Pyruvate oxidation

• Krebs cycle

• Electron transport chain

Stages of Photosynthesis:

• Light reactions

• Calvin cycle

Mitosis and Meiosis

Mitosis: Produces two identical diploid cells for growth and repair.

Meiosis: Produces four non-identical haploid gametes for sexual reproduction.

• Stages: Prophase, Metaphase, Anaphase, Telophase (I and II for meiosis)

• End products: Mitosis yields diploid cells; meiosis yields haploid cells.

Unit 4 Portion

Mendelian Genetics

Gregor Mendel discovered the basic principles of heredity through experiments with pea plants.

• Key terms: Character, trait, dominant, recessive, homozygous, heterozygous, monohybrid, dihybrid, F1, F2

• Blending inheritance hypothesis: Incorrect idea that parental traits mix in offspring.

• Mendel's Model: Traits are inherited as discrete units (genes).

• Genotype vs. Phenotype: Genotype is genetic makeup; phenotype is observable traits.

• Codominance: Both alleles are expressed.

• Incomplete dominance: Heterozygote shows intermediate phenotype.

Punnett Squares

Punnett squares are used to predict the probability of offspring genotypes and phenotypes.

• Monohybrid cross: One trait, e.g., Aa x Aa

• Dihybrid cross: Two traits, e.g., AaBb x AaBb

• Sex-linked traits: Traits located on sex chromosomes

Chromosomal Basis of Inheritance

Genes are located on chromosomes, which segregate and assort independently during meiosis.

• Thomas Morgan's experiments: Demonstrated linkage and sex-linked inheritance.

Central Dogma: DNA to Protein

The central dogma describes the flow of genetic information:

• Transcription: DNA is transcribed to mRNA.

• Translation: mRNA is translated to protein.

Template and non-template DNA strands: The template strand is used to synthesize mRNA.

Codon table: Used to translate mRNA codons into amino acids.

Mutations

Mutations are changes in DNA sequence.

• Substitutions: One base is replaced by another.

• Insertions and deletions: Bases are added or removed, possibly causing frameshifts.

Directionality of Nucleic Acids

DNA and RNA strands have directionality, described as 5' to 3'. This is crucial for replication, transcription, and translation.

Sample Table: Types of Chemical Bonds

Bond Type	Description	Example
Covalent	Atoms share electrons	H2O
Ionic	Atoms transfer electrons	NaCl
Hydrogen	Weak attraction between polar molecules	Between water molecules

Key Equations

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

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

Additional info:

• Some context inferred from standard General Biology curriculum and chapter coverage.

• Details on Punnett squares, central dogma, and mutation types expanded for clarity.