KnowSoda
ScienceBiology
Ecosystems: fun facts and quiz
The essentials in 7 ideas, with fun facts, an illustrated story and a quiz to see how much you know.
The essentials
Food Chains & Webs
Energy flows from plants to the animals that eat them, and on to predators. Many linked food chains make a food web.
Key fact
Only about 10% of the energy passes from one level to the next.
Producers & Consumers
Producers, like plants and algae, make food from sunlight. Consumers eat other living things, and decomposers, like fungi and bacteria, recycle the dead.
Key fact
Tiny ocean algae make roughly half of Earth’s oxygen.
Biomes
A biome is a large region with its own climate, plants and animals, like rainforests, deserts, grasslands or tundra.
Key fact
Tropical rainforests are home to more than half of land species.
Living Together
Some species team up. Bees pollinate flowers while feeding on nectar, and clownfish shelter in sea anemones while keeping them clean.
Key fact
When both partners benefit, it’s called mutualism.
Keystone Species
A keystone species has a huge effect on its ecosystem compared with its numbers. Take it away, and the whole system can change.
Key fact
Bringing wolves back to Yellowstone in 1995 changed the whole park.
Invasive Species
An invasive species is one brought to a new place where it spreads and causes harm. Not every newcomer is invasive; many settle in quietly.
Key fact
Cane toads, brought to Australia in 1935, now number in the millions.
Biodiversity
Biodiversity is the variety of life in a place. Ecosystems with more species tend to cope better with disease, drought and change.
Key fact
Scientists have named about 2 million species so far.
Fun facts
That energy loss is why big predators are rare: there is only so much food energy left at the top.
Deep-sea vent ecosystems run without sunlight: their producers are bacteria that feed on chemicals.
The Amazon rainforest makes much of its own rain: its trees release water vapour that falls again as rain.
Leafcutter ants don’t eat the leaves they carry: they use them to grow a fungus, and eat that.
Beavers are keystone species too: their dams create whole wetlands.
Burmese pythons, released or escaped from pet owners, now thrive in Florida’s Everglades.
Most species on Earth probably haven’t been discovered yet, especially insects and microbes.
Story: Twenty-Four Rabbits
Twenty-Four Rabbits
1859, Australia. Settler Thomas Austin releases 24 wild rabbits on his estate, so he can go hunting as he did in England.
With mild winters and few predators, they breed and spread. Within decades there are hundreds of millions.
Australia built fences to hold them back. The longest, finished in 1907, ran for over 1,800 km.
True or false?
Tap your answer to see if you got it, and why.
-
Question 1 of 10
A food web is made of many linked food chains.
Show the answer
True. Most animals eat, and are eaten by, more than one species.
-
Question 2 of 10
Mushrooms are decomposers.
Show the answer
True. Fungi break down dead plants and animals, returning nutrients to the soil.
-
Question 3 of 10
Antarctica counts as a desert.
Show the answer
True. Deserts are defined by how little rain or snow falls, not by heat.
-
Question 4 of 10
In mutualism, both species benefit.
Show the answer
True. Like bees and flowers: food for one, pollination for the other.
-
Question 5 of 10
Removing a keystone species can change a whole ecosystem.
Show the answer
True. Other species depend on the role it plays.
-
Question 6 of 10
A species can be non-native without being invasive.
Show the answer
True. It’s only invasive if it spreads and causes harm.
-
Question 7 of 10
Diverse ecosystems tend to recover better from shocks.
Show the answer
True. If one species struggles, others can fill its role.
-
Question 8 of 10
Energy passes up a food chain without any loss.
Show the answer
False. Most of it is used for living or lost as heat at each step.
-
Question 9 of 10
Animals can make their own food from sunlight.
Show the answer
False. That’s what producers like plants do. Animals have to eat.
-
Question 10 of 10
Deserts are always hot.
Show the answer
False. Some of the biggest deserts are cold, like Antarctica and the Gobi.
Keep going in the app
KnowSoda learns what you know and brings back what you’re about to forget. Ecosystems has 6 more ideas at the Advanced and Expert levels.
Sources
- National Geographic Education — Food webs, biomes, keystone species
- NOAA — How much oxygen comes from the ocean?
- Yellowstone National Park (NPS) — Wolf restoration
- Australian Government — Cane toads
- Catalogue of Life — number of described species
- Costanza et al. (2014), changes in the global value of ecosystem services, Global Environmental Change 26
- Surtsey Research Society — Surtsey
