Biology Final Exam ANSWERS

Characteristics of Life

• Reproduction: Continuation of species.

• Organization: Specific structure and specialization.

• Composed of cells: Unicellular or multicellular.

• Adaptation: Adjust to the environment.

• Response to stimuli: Reactions to the environment.

• Energy use: Used for growth and maintenance.

• Growth and development: Increase in size and change shape.

Genetic Engineering

• Human Genome Project: Sequence all human DNA to understand genes.

• Transgenic organisms: Organisms with genes from another organism.

• Clone: Genetically identical copy from a single cell.

• Transformation: Cell takes in external DNA.

• DNA Fingerprinting: Analysis of DNA variations to identify individuals.

• Gel electrophoresis: Separates DNA fragments by size and charge.

• Restriction enzymes: Cut DNA at specific sequences.

• Genetic engineering: Changes to DNA code in organisms.

• Recombinant DNA: DNA from different sources combined.

• Operator site: Where repressor binds to operon.

• RNA polymerase.

• Point mutation: Change of a single nucleotide.

• Stem cell: Undifferentiated cell (no specific "job").

• Gene therapy: Replacing faulty genes with normal ones.

• Frame shift mutation: Shift in the reading frame by inserting or deleting a nucleotide.

Gel Electrophoresis

• DNA has a partial negative charge, moves towards positive end in electric field.

• Smaller DNA fragments move farther.

Levels of Organization

• Population: Group of interbreeding individuals migrating.

• Ecosystem: Interactions of community with environment (e.g., wildfires on grasslands, littering in forest).

• Organ: Specific body part (e.g., stomach with ulcers).

• Organ system: Related organs working together (e.g., hormone concentration in blood).

• Cells: Basic unit of life (e.g. cancer cells in a petri dish).

Lamarck's Hypothesis on Evolution

• Acquired traits during lifetime passed to offspring (selective use/disuse of organs).

Natural Selection

• Individuals better suited to environment survive and reproduce.

Darwin's Theory of Natural Selection

• Natural variation: Differences among individuals (e.g., fruit size).

• Struggle for existence/competition: Competition for resources.

• Adaptation/Survival of the fittest: Inherited characteristics increasing survival.

• Organisms overproduce: More offspring than will survive.

• Speciation: New species arise as populations adapt to niches.

Genetic Drift

• Allele frequency changes randomly in small populations, not necessarily increasing survival.

Punctuated Equilibrium

• Long stable periods interrupted by rapid change.

Evidence for Evolution

• Homologous structures: Similar due to common ancestry.

• Analogous structures: Similar function, different ancestry.

• Vestigial structures: Inherited structures with no current use.

• Comparative embryology: Similarities in development.

• Phylogenetic tree: Diagram showing evolutionary relationships.

Classification

• Seven levels: (Domain), Kingdom, Phylum, Class, Order, Family, Genus, Species.

• Taxonomists group organisms based on evolutionary descent, DNA similarities, biochemistry, embryology, homologous structures, cell structure, nutrient acquisition, metabolism.

Speciation and Evolution

• Gradualism: Slow changes over time in fossil record.

• Co-evolution: Two species evolve in response to each other.

• Adaptive radiation: One species evolves into many due to different habitats.

• Convergent evolution: Unrelated species resemble each other over time.

• Geographic isolation: Species can't interbreed due to physical barriers.

• Behavioral isolation: Different mating rituals prevent interbreeding.

• Temporal isolation: Species breed at different times.

Kingdoms

• Archaebacteria: Prokaryotic, unicellular, either auto/heterotrophic, extreme environments.

• Eubacteria: Prokaryotic, unicellular, mostly heterotrophic, E. coli.

• Protista: Eukaryotic, mostly unicellular, either auto/heterotrophic, Amoeba, algae.

• Fungi: Eukaryotic, mostly multicellular, heterotrophic, mushrooms, yeast.

• Plantae: Eukaryotic, multicellular, autotrophic, mosses, flowering plants.

• Animalia: Eukaryotic, multicellular, heterotrophic, sponges, mammals.

• Canis lupus: Represents Genus and Species; demonstrates Binomial Nomenclature.

Antibiotic Effectiveness Test

• Effectiveness indicated by zone of inhibition.

• Control setup: Quadrant with no change.

• Colony in inhibition zone: Indicates potential antibiotic resistance through mutation.

Cladogram

• Depicts evolutionary relationships.

  • Porifera (Sponges): No Symmetry

  • Cnidardians & Echinoderms: Radial Symmetry

  • All worms, Arthropods: Bilateral Symmetry

  • Worms, arthropods: Cephalization.

  • Flatworms: Show 3 germ layers.

Types of Selection

• Stabilizing: Favors intermediate traits.

• Directional: Favors one extreme.

• Disruptive: Favors both extremes.

Ecology

• Community: Interacting populations of different species.

• Niche: Full range of conditions under which an organism lives and reproduces.

Community Interactions

• Commensalism: One benefits, other unaffected (birds nest in trees).

• Mutualism: Both benefit.

• Competition: Both harmed.

• Parasitism: One benefits, other harmed.

Succession

• Primary: Occurs where no soil exists (e.g., after volcanic eruption); pioneer species break down rocks.

• Secondary: Occurs where soil is present after disturbance (e.g., fire).

Ecological Roles

• Producer: Autotroph, makes own food.

• Consumer: Heterotroph, obtains energy from other organisms.

• Herbivore: Eats plants.

• Carnivore: Eats animals.

• Omnivore: Eats plants and animals.

• Trophic Level: Position in food chain/web. Energy decreases at each level (10% rule).

Ecological Pyramids

• Energy pyramid: Energy decreases at each level.

• Biomass pyramid: Amount of living organic matter decreases at each higher level.

• Number pyramid: Number of individuals decreases at each higher level.

Ecology Matching

• Non-biodegradable: Cannot be broken down by life processes.

• Recycled: Converted to reusable materials.

• Biological magnification: Accumulation of toxins.

• Biodiversity: Variety of living organisms.

• Invasive species: Enters new environment.

• Endangered species: Risk of extinction.

• Sustainable use: Using resources without depletion.

• Conservation: Protecting natural environment.

• Trophic Level: Step in energy transfer.

Carbon/Oxygen Cycle

• Photosynthesis: 6CO2 + 6H2O \rightarrow C6H{12}O6 + 6O2

• Cellular Respiration: C6H{12}O6 + 6O2 \rightarrow 6CO2 + 6H2O

• Decreasing CO2: Planting forests.

• Increasing CO2: Burning fossil fuels.

• Ultimate energy source: Sunlight.

• Reactants and products of photosynthesis and aerobic cell respiration are opposites.

Photosynthesis

• Light Dependent Reactions: Thylakoid membrane, solar energy captured, water split.

• Calvin Cycle: Stroma, CO2 converted to sugar using ATP and NADPH.

Cellular Respiration

• Aerobic: Uses oxygen to make ATP.

• Anaerobic: Does not use oxygen to make ATP.

  • Glycolysis: Cytoplasm, glucose to pyruvic acid; 2 ATP net.

  • Krebs Cycle: Mitochondrial matrix, pyruvic acid broken down, CO2 released; 2 ATP, NADH, FADH2.

  • Electron Transport Chain: Inner mitochondrial membrane, energy from NADH/FADH2 used to make ATP; 32 ATP.

• Lactic Acid Fermentation: Pyruvic acid converted to lactic acid to replenish NAD^+.

• Alcoholic Fermentation: Pyruvic acid converted to ethanol and CO_2 to

• replenish NAD^+.

Genetics

• Genotype: Genetic makeup.

• Phenotype: Physical appearance.

• Homozygous: Pair of identical alleles.

• Heterozygous: Pair of different alleles.

• Law of segregation: Alleles separate during meiosis.

• Law of independent assortment: Alleles assort independently.

Nucleic acids

• Nucleic Acids:

  • DNA double stranded; RNA single stranded.

  • DNA contains deoxyribose; RNA contains ribose.

  • DNA contains thymine; RNA contains uracil.

  • DNA located in the nucleus, chloroplast and mitochondria.

  • mRNA moves from the nucleus to the ribosome.

  • tRNA transports amino acids to the ribosome.

  • rRNA makes up part of the ribosome structure.

Molecular Biology

• Replication: DNA replication occurs in the nucleus. It is the process by which DNA makes copies of itself. The double helix unwinds, and each strand serves as a template for a new complementary strand. This results in two identical DNA molecules.

• Transcription: Transcription occurs in the nucleus. It is the process by which the information in a strand of DNA is copied into a new molecule of messenger RNA (mRNA). DNA sequence is read by an RNA polymerase, which produces a complementary, antiparallel RNA strand