BIS 2B SQ 2025 Study Notes

Trade-offs in Adaptations

  • Concept of Trade-off: Adaptations often involve a trade-off where advantageous adaptations in one area may compromise another.
    • Resource Acquisition: A plant may allocate more energy to root development, improving nutrient uptake, but this could reduce overall growth.
    • Defense Against Herbivores: A species may develop thorns for protection against herbivores, but these thorns may inhibit growth and reproductive output.
    • Environmental Stress: Desert animals may develop a thick skin for water retention, but this may limit their ability to cool down.

Predation Events Dependency

  • Three Successive Events: Predation relies on (1) searching for prey, (2) capturing prey, and (3) consuming prey.
    • Adaptations of Prey:
    • Searching: Camouflage to reduce visibility.
    • Capturing: Speed to escape from predators.
    • Consuming: Chemical defenses to deter consumption.

Stomatal Crypts in Desert Plants

  • Function: Stomatal crypts help reduce transpiration by trapping moisture near the stomata.
  • Effect on CO2 Uptake:
    • Reduced water loss but may lower the rate of CO2 uptake due to limited exposure.

Human Food Preferences Evolution

  • Evolutionary Standpoint: Preference for fats, sugars, and salt helps in energy storage and survival.
  • Modern Consequences: This preference can lead to obesity and health issues in today's environment where high-energy foods are abundant.

Shorebird Foraging and Energy Maximization

  • Snail Size Preference: Birds likely choose medium-sized snails to maximize energy intake per unit handling time.
  • Ecological Factors: Availability and abundance of certain sizes in the environment may influence prey choice.

Key Definitions

  • Endotherm: Organisms that maintain body temperature through metabolic processes.
  • Ectotherm: Organisms that rely on external conditions for body heat.
  • Adaptation vs. Acclimation: Adaptation is a genetic change over time, while acclimation is a short-term physiological adjustment.
  • C3 vs. C4 Photosynthesis: Different pathways plants use to fix carbon, with C4 being more efficient in high temperatures.
  • Semelparous: Species that reproduce only once.
  • Iteroparous: Species that reproduce multiple times throughout their life.

CO2 Effects on C3 and C4 Plants

  • Impact of Increased CO2: Positive for both, but C4 plants might outperform C3 as temperatures rise.
  • Temperature Effects: C3 plants thrive at lower temperatures; C4 plants are better adapted to higher temperatures.

Life History Strategies: r vs. K

  • r-Selected Traits: High reproductive rates, short lifespan, low parental care.
  • K-Selected Traits: Low reproductive rates, longer life span, high parental investment.

Anadromous Fish Salinity Adjustment

  • Acclimation vs. Adaptation: The salmon adjusting to salinity is an example of acclimation since they are adjusting to immediate environmental changes.

Biomass Production & CO2 Experiments

  • Findings: Increasing CO2 does not significantly enhance biomass production in natural conditions as seen in controlled experiments.

Limiting Nutrient Determination

  • Limiting Nutrient: Determined by comparing growth data; key nutrient depends on results from controlled experiments.

Evaporation as a Cooling Mechanism

  • Trade-off: Cooling through evaporation risks increased dehydration and limits nutrient allocation for other processes.

Deep Sea Fish Life History

  • Life History Traits: The species described demonstrates K-selection due to low reproductive rates and long lifespan.