science living world

Q1: What is an ecosystem?
A: An ecosystem is the interaction between living (biotic) and non-living (abiotic) components in an environment. It includes food chains, energy flow, habitats, and interdependence.

Q2: What are abiotic factors?
A: Abiotic factors are the non-living physical and chemical elements in an ecosystem, such as sunlight, water, soil, pH, salinity, and temperature.

Q3: What are examples of abiotic features in an ecosystem and how do they affect life?
A:

  • Light: Needed for photosynthesis

  • Temperature: Affects metabolic rate

  • Water: Vital for life processes

  • Soil type/pH: Affects plant growth

  • Salinity: Influences water balance

  • Oxygen: Required for respiration

Q4: How do we measure abiotic features?
A:

  • Thermometer (temperature)

  • Light meter (light intensity)

  • pH probe (acidity/alkalinity)

  • Salinity meter

  • Anemometer (wind speed)

Q5: What is the carbon cycle?
A: The carbon cycle moves carbon through the atmosphere, organisms, and Earth via processes like photosynthesis, respiration, decomposition, and combustion.

Q6: What is the nitrogen cycle?
A: The nitrogen cycle involves nitrogen-fixing, nitrifying, and denitrifying bacteria to recycle nitrogen essential for plant growth.

Q7: What does "biotic" mean in ecology?
A: Biotic refers to the living components of an ecosystem, such as plants, animals, fungi, and bacteria.

Q8: What is a biomass pyramid?
A: A diagram that shows the mass of living material at each trophic level in a food chain. Energy decreases (~90% lost) at each level.

Q9: What is a food chain?
A: A simple diagram that shows the flow of energy as organisms consume one another (e.g., Grass → Grasshopper → Frog → Snake → Hawk).

Q10: How does energy flow through an ecosystem?
A: Energy from the sun flows to producers, then consumers. Most is lost as heat or waste at each level.

Q11: What are the main types of biotic relationships?
A:

  • Competition: Organisms fight for resources

  • Predation: One organism hunts another

  • Mutualism: Both benefit (e.g., bee & flower)

  • Commensalism: One benefits, other unaffected

  • Parasitism: One benefits, other is harmed

🌱 Sustainability & Human Impact

Q12: What is a renewable resource?
A: A resource that naturally replenishes, like sunlight or wind.

Q13: What is sustainable practice?
A: Using resources in a way that does not harm future generations.

Q14: How do natural disasters impact ecosystems?
A: They change abiotic factors (like soil or climate) and can destroy habitats or reduce populations of biotic factors.

Q15: How do humans impact ecosystems?
A: Through pollution, deforestation, overfishing, habitat destruction, and contributing to climate change.

Q16: What are Aboriginal and Torres Strait Islander land practices?
A: Practices like fire-stick farming and seasonal calendars that maintain sustainability and balance in ecosystems.

Q17: How do Indigenous and European land management systems compare?
A:

  • European: Often exploitative and focused on economy

  • Indigenous: Sustainable and land-focused

  • Best Practice: Combines both to protect land and support productivity

🧠 Body Systems & Coordination

Q18: What are the five main sense organs and their functions?
A:

  • Eyes: Sight

  • Ears: Hearing and balance

  • Skin: Touch and temperature

  • Tongue: Taste

  • Nose: Smell

Q19: What is the stimulus → receptor → response pathway?
A:

  1. Stimulus (e.g., heat)

  2. Receptor (e.g., skin detects it)

  3. Response (e.g., pull away hand)

Q20: What is the difference between the CNS and PNS?
A:

  • CNS (Central Nervous System): Brain and spinal cord

  • PNS (Peripheral Nervous System): Nerves linking body to CNS

Q21: What are the types of neurons and their functions?
A:

  • Sensory neurons: Carry messages from receptors to CNS

  • Motor neurons: Carry messages from CNS to muscles/glands

Q22: What is the full coordination pathway for a response?
A: Stimulus → Receptor → Sensory neuron → CNS → Motor neuron → Effector (muscle/gland)

Q23: What does a skin sensitivity investigation show?
A: It shows that different parts of the body have varying receptor density. Fingertips are more sensitive than arms or back.