Bio 101 Unit 2

Biotechnology in Our Lives: Summary and Key Themes

Summary of Events

  • DNA and Its Applications: DNA is unique to individuals (except identical twins) and can be extracted from various biological materials. It plays a crucial role in crime solving, paternity testing, and genetic testing.

  • Structure of DNA: DNA is a double helix composed of nucleotide pairs (A-T, C-G) connected by hydrogen bonds. The central dogma describes the flow of genetic information from DNA to RNA to protein.

  • Biotechnology Overview: Biotechnology involves modifying genetic material for new functions. Applications include medicine (vaccines, antibiotics), agriculture (GMOs), and industrial processes (biofuels).

  • DNA Extraction and Analysis: Techniques like gel electrophoresis and PCR (Polymerase Chain Reaction) are used for DNA analysis and amplification.

  • Cloning: Molecular cloning allows for gene copying, while reproductive cloning creates genetically identical organisms (e.g., Dolly the sheep).

  • Gene Therapy: Introduces non-mutated genes to treat genetic diseases. Gene therapy is still largely experimental.

  • Genomics and Proteomics: Genomics studies entire genomes, aiding in disease identification and agricultural improvements. Proteomics examines protein functions.

  • Case Studies:

    • Pardis Sabeti: Works on diagnosing and understanding genetic resistance to Lassa fever.

    • Jay Keasling: Develops microbes to produce drugs and biofuels from plant sugars.

    • Karen Nelson: Studies human microbiomes and their implications for health.

    • Rob Frehley: Focuses on drought-resistant crops using genetic engineering.

Main Themes

  • Genetic Uniqueness and Identity: Each individual's DNA is unique, emphasizing the importance of genetics in personal identity and forensic science.

  • Biotechnology's Impact on Health: Advances in biotechnology have significant implications for medicine, including disease treatment and prevention.

  • Ethical Considerations: Cloning and genetic modification raise ethical questions about identity, safety, and ecological impacts.

  • Interconnectedness of Life: The universal genetic code supports the idea that all living organisms are related, highlighting the interconnectedness of life.

  • Innovation and Sustainability: Biotechnology offers solutions for sustainable agriculture and renewable energy, addressing global challenges like food security and climate change.

Motifs

  • Transformation: The ability to transform organisms through

Lecture Notes: Species Interactions and Plant Reproduction

Overview of Species Interactions

  • Mutualism: Both species benefit.

    • Example: Termites and microorganisms digesting cellulose.

    • Example: Lichens (fungus + algae).

  • Predation: One species consumes another for energy.

    • Example: Lynx and snowshoe hare population cycles.

  • Competition: Species compete for resources.

    • Competitive exclusion principle: Two species cannot coexist if competing for identical resources.

  • Commensalism: One species benefits, the other is unaffected.

    • Example: Birds nesting in trees.

  • Parasitism: One species benefits at the expense of another.

    • Example: Tapeworms in humans.

Plant Reproduction Focus: Angiosperms

  • Angiosperms: Flowering plants, primary reproductive structure is the flower.

Flower Structure

  • Female Part (Carpel):

    • Stigma: Sticky tip for pollen capture.

    • Style: Supports stigma.

    • Ovary: Contains ovules (eggs).

  • Male Part (Stamen):

    • Anther: Produces pollen.

    • Filament: Supports anther.

Pollination and Fertilization

  • Pollination: Transfer of pollen from anther to stigma.

    • Preferably between different flowers to avoid inbreeding.

  • Fertilization: Occurs after pollination.

    • Pollen forms a tube to deliver sperm to the ovule.

    • Results in a zygote and endosperm (nutrient for the seed).

Seed Development

  • Seeds remain dormant until conditions are favorable (water presence).

  • Germination:

    • First structure to emerge is the radical (root).

    • Followed by the shoot (seeking light for photosynthesis).

Pollination Ecology

  • Pollinators: Animals that transfer pollen.

    • Examples: Bees, butterflies, bats, birds.

  • Pollination Syndromes: Traits of flowers that attract specific pollinators (color, shape, scent).

Trophic Cascades and Ecosystem Dynamics

  • Trophic Cascade: Ecological process starting from top predators affecting lower levels.

    • Example: Wolves

Climate Change Lecture Notes

Resources for Study

  • Textbook Sections: 20.2 and 21.2

  • Website: NASA's Global Climate Change - Vital Signs of the Planet

Overview of Climate Change

  • Focus on Water Cycle and Carbon Cycle as they relate to climate change.

  • Key elements recycled in nature: Carbon, Nitrogen, Hydrogen, Oxygen, Phosphorus, Sulfur.

Water Cycle

  • Water Composition:

    • 97.5% saltwater (not drinkable)

    • 2.5% freshwater (99% in ice/underground)

    • Less than 1% available in lakes/rivers.

  • Water Recycling Processes:

    • Evaporation: Water to vapor.

    • Transpiration: Evaporation from plants.

    • Condensation: Vapor to liquid (cloud formation).

    • Precipitation: Rain, snow, sleet.

    • Subsurface Water Flow: Water percolating into aquifers.

    • Surface Runoff: Water flowing into streams/lakes.

    • Ice/Snow Melt: Solid to liquid, contributing to runoff.

Carbon Cycle

  • Importance of Carbon:

    • Primary component of organic molecules.

    • Energy source from carbohydrates and fossil fuels.

  • Biological Carbon Exchange:

    • Autotrophs: Producers (photosynthesis).

    • Heterotrophs: Consumers (cellular respiration).

  • Greenhouse Effect:

    • Beneficial for life; traps heat.

    • Enhanced by human activities (burning fossil fuels).

Climate vs. Weather

  • Climate: Long-term atmospheric conditions.

  • Weather: Short-term atmospheric conditions.

Global Warming vs. Climate Change

  • Global Warming: Increase in Earth's average temperature.

  • Climate Change: Broader term encompassing changes in temperature, precipitation, etc.

Evidence of Climate Change

  • Antarctic Ice Cores: Historical climate data.

  • Current CO2 Levels: Rising above 300 ppm since 1950.

Consequences of Climate Change

  • Sea Level Rise:

    • Melting ice sheets (e.g., Greenland).

    • Threat to coastal communities (e.g., New Orleans,

Notes on Biodiversity and Its Importance

Definition of Biodiversity

  • Biodiversity: Refers to the variety of life forms on Earth.

  • Types of Biodiversity:

    • Genetic Diversity: Variation in genetic makeup within a species; essential for adaptation.

    • Chemical Diversity: Variety of chemical compounds produced by organisms; important for human health.

    • Ecosystem Diversity: Variety of ecosystems in a region; crucial for species interactions and productivity.

    • Species Diversity: Number and variety of species in a region.

Importance of Genetic Diversity

  • Genetic diversity is crucial for a species' ability to adapt to environmental changes.

  • Higher genetic diversity within a genus increases potential for adaptation.

  • Loss of genetic diversity can lead to vulnerability and extinction.

Consequences of Reduced Biodiversity

  • Food Supply: Artificial selection in agriculture can lead to inbreeding, making crops susceptible to pests and diseases.

  • Ecosystem Loss: Destruction of ecosystems (e.g., prairies) leads to loss of species interactions and soil productivity.

Conservation Efforts

  • Global Seed Vault: Norway's facility for preserving seeds of diverse crops to safeguard against extinction.

  • Bioprospecting: Ethical concerns regarding the exploitation of indigenous knowledge for profit without fair compensation.

Ecosystem Diversity

  • Ecosystems provide essential services and interactions among species.

  • Loss of ecosystems can lead to decreased biological productivity and species extinction.

Threats to Biodiversity

  1. Habitat Loss: Major cause of species endangerment; can occur through elimination, fragmentation, or degradation.

  2. Overharvesting: Unsustainable practices can lead to population collapse.

  3. Invasive Species: Non-native species can disrupt local ecosystems and outcompete native species.

  4. Climate Change: Alters habitats and affects species survival, e.g., polar bears losing sea ice.

Current Extinction Crisis

  • Human actions have led to a sixth mass extinction, with extinction rates significantly higher than normal.

  • Example: The dodo bird's extinction due to overhunting and habitat destruction.

Actions to Prevent Extinction

  • Make informed choices regarding consumption and support sustainable practices.

  • Reduce carbon footprint to mitigate climate change.

  • Support conservation efforts and habitat restoration.

  • Visit and support zoos and aquariums that engage in breeding programs for endangered species.