Environment

1. Environment

2. Habitats Organisms will live and grow in places where conditions are suitable. These conditions include: • Temperature • Amount of light • Availability of water and food • Availability of carbon dioxide (for plants) or oxygen (for animals) • For example, this is why you wouldn’t find organisms adapted for the desert, like camels or snakes, in large numbers in Britain.

3. Competition • Plants will compete with each other for: • Space • Water • Nutrients from the soil. • Animals, however, will compete for: • Space • Water • Food (and sometimes a mate).

4. Predation Predation is when animals are eaten by other animals. • The animal being eaten is called the ____ • The animal thateats it is called the _________

5. The arrows show which way the energy is going in the chain Food Chains A food chain shows what is eaten by what…

6. Food webs Food webs contain many interlinking food chains…

7. e.g take out the crab: What would happen if an animal or organism was “taken out”? • What would happen to the population of flat winkles? • What would happen to the population of herring gulls? It would increase, because they are not getting eaten as much It would decrease, because there is not as much food

8. Consider the same food web: • What might happen to the population of seals if the population of algae increases? • What might happen to the population of sea urchins if the population of crabs decreases? increase increase

9. Top carnivore Secondary consumer Primary consumer Producer

10. Some definitions… Usually plants. Anything that takes energy from the sun. Animals that only eat plants An animal that eats something else An animal that eats producers An animal that eats primary consumers An animal that eats secondary consumers Eats only animals Not eaten by anything else Eats both animals and plants Producer fgfg Herbivore Consumer Primary consumer Secondary consumer Tertiary consumer Carnivore Top carnivore Omnivore

11. A “Pyramid of Numbers” A pyramid of numbers shows how many animals or organisms we are talking about. For example, consider the following food chain:

12. A pyramid of numbers for this food chain would look like this: One owl Some voles Lots of grass

13. Another example: Consider the food chain: GrassRabbitFoxFleas Lots of fleas One fox Some rabbits Lots of grass

14. “A Pyramid of Biomass” A pyramid of biomass shows how much the creatures at each level would weigh. Consider the same food chain: GrassRabbitFoxFleas

15. GrassRabbitFoxFleas Pyramid of numbers: Pyramid of biomass:

16. What are the two main differences between the two pyramids? • Pyramids of number show HOW MANY organisms we are talking about, whereas pyramids of biomass show their MASS • Pyramids of number can look a little odd, whereas pyramids of biomass ALWAYS look like a pyramid:

17. At each stage in a food chain energy gets “lost”: 1000J 100J 10J Around 10% of the energy from each organism is passed on to the consumer. So where does the rest go?

18. What are the two main ways energy is lost? 1) Through waste materials • Through different living processes, such as movement, growth etc. This energy is supplied by respiration. • The BIG energy usage in birds and mammals is caused by trying to keep the body at its correct temperature – body heat is always lost to the the surroundings.

19. How could we reduce this energy loss? • Reduce the number of stages on a food chain • Restrict energy loss by restricting movement (like battery hens) and controlling the temperature of their surroundings