Biology Short Answers Q1 Flashcards
Similarties and Differences
Comparing Ecosystems
List Abiotic Examples and Biotic Examples
Similarities: Both have species at different trophic levels, depend on each other, can reach equilibrium if undisturbed.
Differences: Terrestrial is land-based (sunlight/temperature most important abiotic factors), aquatic is water-based (depth and flow rate most important). Aquatic ecosystems generally support more life and are more stable.
Abiotic examples (terrestrial): sunlight, temperature, soil; (aquatic): water depth, oxygen, acidity.
Biotic examples (terrestrial): trees, insects, mammals; (aquatic): fish, algae, microorganisms.
Energy Flow in Ecosystems
Sun provides energy for photosynthesis, heating, and evaporation.
Energy flows through food chains and food webs, starting with producers.
Energy pyramid: 100% energy at producers, only 10% passed to each level above.
Only 10% passed because organisms use energy for movement, growth, and reproduction; the rest is lost as heat
Ecological Roles and Niches
Ecological Niche: Role and position a species has in its environment, including biotic and abiotic factors.
Producers: 1st trophic level; Primary consumers:
2nd trophic; Secondary consumers:
3rd trophic; Tertiary consumers: 4th trophic.
Autotrophs (producers) make their own food; heterotrophs (consumers) must eat others for energy
Sustainability and Human Impact
A sustainable ecosystem maintains relatively constant biotic/abiotic features and supports biodiversity.
Sustainable practices: recycling, reusing, crop rotation. Unsustainable practices: deforestation, fossil fuel use.
Easter Island: Unsustainable tree cutting led to ecosystem collapse and societal decline
Photosynthesis and Cellular Respiration
Photosynthesis word equation: Carbon dioxide + water + light → glucose + oxygen
Chemical equation: 6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂
Cellular respiration word equation: Glucose + oxygen → carbon dioxide + water + energy.
Chemical equation: C₆H₁₂O₆ + 6O₂ → 6CO + 6H₂O + energy.
They are complementary: photosynthesis removes CO₂ and produces O₂ ; respiration
uses O₂ and releases CO₂
Plants perform both processes; animals only perform respiration.
Greenhouse Gases and Acid Precipitation
Greenhouse gases: water vapor, carbon dioxide, methane.
Greenhouse effect: Gases trap heat, keeping Earth warm enough for life.
Enhanced greenhouse effect: Increased carbon dioxide from burning fossil fuels leads to global warming.
Acid precipitation forms when nitrogen oxides and sulfur dioxide react with water to form acids; lowers soil nutrients and harms aquatic life
Biogeochemical Cycles
Water Cycle: Evaporation, transpiration, condensation, precipitation.
Carbon Cycle: Carbon moves through photosynthesis, respiration, decomposition,
combustion.
Nitrogen Cycle: Nitrogen fixation by bacteria turns atmospheric N₂ into ammonia usable by plants; denitrification returns N₂ to atmosphere.
Bacteria are essential for converting nitrogen into usable forms (ammonia, nitrates).
Humans impact cycles: burning fossil fuels (carbon), fertilizer use (nitrogen), pollution (water).
