Today we will: KNOW: » The Sun is the main source of energy on Earth, green plants are able to harness this energy via photosynthesis and are categorised as producers. » Plants are a source of energy and nutrients for the other organisms. BE ABLE TO: » Recognise that plants use photosynthesis to produce food. » Understand that animals cannot create their own food therefore rely upon plants. Think about the following questions and put your ideas on paper. » How important do you think the environment is for life? Explain. » Are there some parts of YOUR environment that you couldn’t live without? List them and explain. » If you were forced to live in the Australian desert for a year, what would you need to keep in mind to survive? » We can classify living things in many different ways. Today, we will classify them based on what they eat. Can you list some other ways living things are classified? » The Sun is the main source of energy on Earth. » Plants are the only living things which can absorb the Sun’s energy and transfer it into chemical energy to live. » This is a process called PHOTOSYNTHESIS. There is something in leaves called CHLOROPHYLL that helps them absorb light energy from the sun and helps make leaves look green. Next week in prac, we will be seperating the different colours found in some leaves. » Animals can’t make their own energy. They need to take it from other sources. Therefore they are called consumers. » Plants are called producers. They are herbivores - eat primary producers (plants). Second order Consumers (carnivores) - eat primary consumers (herbivores). Fourth Order Consumer Third Order Consumer Second Order Consumer First Order Consumer Producer 4th order consumer 3rd order consumer 2nd order consumer 1st order consumer Producer The Pond Fungi – Example: Mushrooms Bacteria Some insects like the dung beetle Whenever something that was alive dies, the decomposers get it. Decomposers break down nutrients in the dead "stuff" and return it to the soil. The producers can then use the nutrients and elements once it's in the soil. The decomposers complete the system, returning essential molecules to the producers. Do you like to play games? If you do, you will need energy. Every time you run or jump, you are using up energy in your body. How do you get the energy to play? You get energy from the food you eat. Similarly, all living things get energy from their food so that they can move and grow. As food passes through the body, some of it is digested. This process of digestion releases energy. A food chain shows how each living thing gets its food. Some animals eat plants and some animals eat other animals. Each link in this chain is food for the next link. A food chain always starts with plant life and ends with an animal. » The feeding relationships between producer and consumers can be written down in the steps called a food chain. » Each arrow indicates “is eaten by”. It also shows the flow of energy. » 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. If you’re a little confused, look at it this way… » FOOD CHAIN… It actually looks like a chain, there is one link after another. » FOOD WEB… It looks a little like a spider’s web, full of aroows going in all sorts of directions. »Find at least 3 food chains in the following food web. W/S: Food Webs 1 & 2 Match the word to the meaning. Word Meaning Herbivore An animal that eats only plants Producers Organisms that make their own food Omnivores Animals that eat plants and animals Consumers Organisms that eat other organisms or their products Carnivores Animals that eat only meat (other animals) Decomposers Bacteria & Fungi which breakdown plant and animal remains Food Chain A feeding relationship between producers & consumers Food Web When many food chains are interlocked together Why Do Herbivores Need to Eat MORE than Carnivores? » Animals move around and loose their energy as heat (perspiration) and as waste (excretion of urine and faeces – poo!) » Plants do not loose a lot of energy because they do not move or digest their food. What Human Impacts on the Environment Can YOU Think Of? »The three largest impacts: ˃Deforestation ˃Agriculture ˃Introduced Species DEFORESTATION Deforestation is the removal of a forest or stand of trees where the land is thereafter converted to non-forest use. AGRICULTURE Agriculture is the use of land for crops and farming. Damage is done by: land clearing, irrigation, soil use, adding fertilisers/chemicals etc…. INTRODUCED SPECIES Introduced species are foreign species that have arrived accidentally or have been introduced to a new area. Read the following paragraph about who eats whom in the Antarctic and draw a food chain that shows the feeding relationships in this habitat. Don’t forget that your food chain must start with a producer!