Ecosystems, Populations and Land Use

Biotic and abiotic factors, energy through food chains and webs, what changes the size of a population, and how land use alters ecosystems.

11 questions, free, marked as you go with a worked explanation on every one.

What this covers

The questions

  1. In a wetland ecosystem, which of these is an abiotic factor?
  2. Why does an energy pyramid narrow sharply at each level going upward?
  3. A deer population starts the year at 1 200. Over the year there are 340 births and 180 deaths, 45 deer move into the area and 60 move away. What is the population at the end of the year?
  4. Purple loosestrife was introduced to western Canadian wetlands from Europe. Why can an introduced species like this cause such damage?
  5. Which pair of biomes best describes the two most widespread natural regions of Alberta?
  6. An ecologist counts 96 plants in a 4 m by 4 m sample square. What is the population density, in plants per square metre?
  7. Draining a wetland to create farmland is an example of a land use practice. What is a likely ecological consequence?
  8. In a grassland food chain, grass is eaten by grasshoppers, which are eaten by mice, which are eaten by hawks. How many levels are there in this food chain, counting the grass as the first?
  9. A producer contains 3 000 kJ of energy. Following the 10% rule, how much energy is available to the primary consumer that eats it?
  10. A food chain is listed in order: grass, grasshopper, frog, snake, hawk. How many consumers are in this food chain?
  11. Which organism role breaks down dead plant and animal matter, returning nutrients to the ecosystem?

Answer these free