1. NEX T

2. In order to live animals need energy. Some animals get the energy they need to live from eating plants and other vegetation - herbivores. Some animals get their energy from eating other animals - carnivores. Some animals eat both plants and other animals - omnivores. NEX T

3. Animals that eat plants are called herbivores. Herbivores have evolved to eat plants. They have specialised teeth and stomachs to enable them to get the energy they need from plants. deerrabbitcow Herbivores are primary consumers as they eat only plants. NEX T

4. Animals that eat meat are called carnivores. Carnivores have evolved to eat meat. Some have specialised teeth and stomachs to enable them to get the energy they need from the bodies of other animals. spidersnakewolf penguins It is not necessary to have teeth or claws to be a carnivore. Carnivores that eat herbivores are called secondary consumers. Carnivores that eat other carnivores are called tertiary consumers. NEX T

5. Animals that eat plants and meat are called omnivores. Humans and chickens are examples of omnivores. These animals are consumers. Omnivores have stomachs that enable them to eat and digest both plants and meat. They have teeth, although some have hard beaks instead. NEX T

6. All living organisms require energy and the ultimate source of all this energy is the sun. Solar energy is trapped by plants, and then transferred from organism to organism in a food chain. In 1927, a scientist named Charles Elton developed this idea of a food chain to show how living things get their food. Food chains show a direct line of energy transfer from the sun to the producer (plants) to consumers. At each stage in this transfer, a large percentage of this energy is lost to the environment. NEX T

7. producer primary consumer tertiary consumer secondary consumer sun water decomposers fungi NEX T

8. Eaten by: Food chains show what eats what in order to gain the energy it needs to live. Food chains use arrows to show the process. There are no simple chains like this, as chickens eat more than grain and foxes eat more than chickens. weedschick NEX T The arrows between each item in a food chain always point in the direction of energy flow - from the food to the feeder e.g. grain is eaten by a chick which is eaten by a fox. Each link in this chain is food for the next link. A food chain always starts with plant life and ends with an animal. Anything that affects one link, affects everything in the chain. fox

9. The further along the food chain you go, the less food (and hence energy) remains available. Food chains are generally short, as a lot of energy is lost at each stage. Some of the energy goes into growth and the production of offspring, while some is used in movement and respiration and some is lost through excretion. In a food chain, energy is passed from one link to another. When a herbivore eats, only a fraction of the energy that it gets from the plant food becomes new body mass; the rest of the energy is lost as waste or used up by the herbivore to carry out its life processes e.g. movement, digestion, reproduction. Therefore, when the herbivore is eaten by a carnivore, it passes only a small amount of total energy (that it has received) to the carnivore. Of the energy transferred from the herbivore to the carnivore, some energy will be ‘wasted’ or ‘used up’ by the carnivore. The carnivore then has to eat many herbivores to get enough energy to grow. Many herbivores are needed to support a few carnivores. Can you explain in your own words why are there more herbivores than carnivores? NEX T

10. Most food chains have no more than four or five links. There cannot be too many links in a single food chain because the animals at the end of the chain would not get enough food (and hence energy) to stay alive. Most animals are part of more than one food chain and eat more than one kind of food in order to meet their food and energy requirements. These interconnected food chains form a food web. A food web is a complex system made up of many food chains. NEX T

11. Nearly all food webs start with a green plant. Plants are called producers because they are able to use light energy from the Sun to produce food (sugar) from carbon dioxide and water. producers consumers NEX T

12. Animals are consumers as they cannot make their own food so must eat plants and/or other animals. Some consume plants to get the energy they need to live while others consume other animals. chickwormweeds producers consumers NEX T people

13. Animals that are eaten by other animals are called prey. Some prey animals are herbivores. Some omnivores and carnivores are also prey to other animals. chickwormfox NEX T

14. Animals that eat other animals are called predators. Some animals are predators and prey. This means they eat some animals but are eaten by others. The top predator that is prey to no other animal is called an apex predator. chicken hawk wormchick NEX T

15. There are decomposers (bacteria and fungi) which feed on decaying matter. These decomposers speed up the decaying process that releases mineral salts back into the food chain for absorption by plants as nutrients. Living organisms require nutrients, especially carbon and nitrogen. They take these from the environment. If this was just a one-way process, our ecosystems would soon run out of these nutrients. They are returned to the environment with the help of bacteria. A decaying plant, for example, will be broken down into nutrients that enrich the soil. This in turn supports the growth of more plants.

16. herbivore omnivore carnivore insectivore decomposer NEX T predator nutrients prey producer consumer eats plants eats both plant and animal foods meat-eating animals An animal that feeds on insects and other invertebrates e.g. bacteria and fungi, which feed on decaying matter animal that preys on others Animals are consumers as they cannot make their own food so must eat plants and/or other animals. Some consume plants to get the energy they need to live while others consume other animals. animal hunted and killed by another for food Plants are called producers as they are able to use light energy from the Sun to produce food (sugar) from carbon dioxide and water. substance that provides nourishment essential for maintenance of life and growth

17. NEX T Primary consumers Secondary consumers Tertiary consumers are the lowest animal level of the food chain include predators and people may be predators, scavengers and sometimes people These categories are very broad, and many animals fit into more than one group. What happens if one element is removed from a food chain? Name an animal that would be at the top of a food chain What might happen in a food chain if pesticides were used to eradicate particular insects? e.g. field is ploughed up, so a rabbit has no grass, therefore fewer rabbits. It could result in fewer foxes, even though foxes don’t eat grass foxes, as nothing eats foxes residual spray may contaminate waterways or soil and the food chain could be affected.

18. Co-operation, competition and predation and how they affect population growth Effect of overpopulation on the amount of resources available within an ecosystem Effect of natural hazards on populations Adaptation and its effects on the population Reasons for extinction of a species (including man-made and natural causes)