Changes in Living Systems
Ecosystems and succession, the cycling of matter and energy, and how populations adapt.
11 questions, free, marked as you go with a worked explanation on every one.
What this covers
- limiting factors and carrying capacity
- food webs
The questions
- What is ecological succession?
- Roughly what proportion of energy passes from one trophic level to the next?
- Which statements about the cycling of matter are correct? Select all that apply.
- What is a limiting factor for a natural population?
- How does natural selection lead to adaptation in a population?
- A wetland is drained for farmland. What is the most likely ecological effect?
- Five years after a wildfire, a study plot contains 40 shrubs. Surveys show the plot is gaining about 15 more shrubs each year as succession continues. If that rate holds, how many shrubs would you expect in the plot in year 12 after the fire?
- In a grassland plot near Lethbridge, the producers capture 40 000 kJ of energy over a season. Using the usual estimate that about 10% of the energy at one trophic level passes to the next, how much energy is available to the secondary consumers?
- A producer contains 100 000 kJ of energy. Following the 10% rule across three energy transfers, how much energy reaches the fourth trophic level?
- A food chain is listed in order: algae, zooplankton, small fish, large fish. Counting the producer as position 1, what position is the large fish?
- Why do food chains rarely have more than four or five trophic levels?