Species & Populations
Define “species”
What is a group of organisms that can interbreed to produce fertile offspring?
Producers occupy which trophic level?
What is the first trophic level?
Define “food web”
What is a network of interconnected food chains?
Name the three common ecological pyramids.
What are pyramids of numbers, biomass, and productivity?
Define GPP.
What is the total energy captured by producers via photosynthesis per unit area per time?
Define “population”
What is a group of the same species living in the same area at the same time?
Identify the trophic level of a primary consumer.
What is the second trophic level?
If a predator is removed, what may happen to its prey population?
What is it increases (initially), potentially causing overgrazing, followed by a drop from lack of resources?
Which pyramid best shows energy flow per unit area per time?
What is a pyramid of productivity?
Define NPP.
What is energy available to consumers after producer respiration (NPP = GPP − R)?
Give one density-dependent limiting factor.
What is predation / disease / competition (any one)?
What is the main energy source for most ecosystems?
What is the Sun?
Name one possible effect of removing a producer from a food web.
What is consumers decrease due to reduced energy/biomass input?
Describe one difference between pyramid of numbers and biomass.
What is numbers show counts; biomass shows mass of living material (any clear contrast)?
Why is NPP always less than GPP?
What is some energy is used in respiration by producers?
Explain one way competition can affect a population.
What is reduced growth/survival/reproduction due to limited resources (any one explained)?
Explain why energy decreases up a food chain.
What is energy is lost as heat through respiration and waste/uneaten parts?
Explain what a trophic cascade is (in simple terms).
What is changes at one trophic level cause knock-on effects at other levels?
Explain why a pyramid of numbers can be inverted.
What is one producer (e.g., tree) can support many consumers (e.g., insects)?
Give two reasons energy transfer is inefficient.
What are heat loss in respiration, waste (feces), uneaten parts, movement (any two)?
Suggest why an invasive species may reduce a native population.
What is it outcompetes for resources / has no predators / preys on natives (any one justified)?
Suggest why food chains are usually short (4–5 levels).
What is too little energy remains at higher trophic levels to support another level?
Suggest one reason food webs are more stable than single food chains.
What is alternative feeding pathways reduce reliance on one species?
Explain why pyramids of productivity are always upright.
What is energy is lost between trophic levels so less is available at higher levels?
Explain why bioaccumulation/biomagnification is worse at higher trophic levels.
What is toxins build up in tissues and are passed on; top consumers eat many contaminated organisms so concentration increases?