Food chains and webs whats for dinner

Every plant and animal species, no matter how big or small, depends to some extent on another plant or animal species for its survival. It could be bees taking pollen from a flower, photosynthesis of plants, deer eating shrub leaves or lions eating the deer.

A food chain shows how energy is transferred from one living organism to another via food. It is important for us to understand how the food chain works so that we know what are the important living organisms that make up the food chain and how the ecology is balanced.

Photosynthesis is only the beginning of the food chain. There are many types of animals that will eat the products of the photosynthesis process. Examples are deer eating shrub leaves, rabbits eating carrots, or worms eating grass. When these animals eat these plant products, food energy and organic compounds are transferred from the plants to the animals.

These animals are in turn eaten by other animals, again transferring energy and organic compounds from one animal to another. So for how many levels does this go on? To follow the food chain to its different levels and know how it works go to this site.

The page also contains names and definitions of terms used to describe the 'players' in the food chain- producers, consumers, herbivores. You can also refer to the diagrammatic representations of food chains, food webs and ecological pyramids.

A food chain describes how energy and nutrients move through an ecosystem. At the basic level there are plants that produce the energy, then it moves up to higher-level organisms like herbivores. After that when carnivores eat the herbivores, energy is transferred from one to the other. To understand how this happens visit the link.

In the food chain, energy is transferred from one living organism through another in the form of food. There are primary producers, primary consumers, secondary consumers and decomposers- all part of the food chain. Follow this link for a good introduction to how food chains work. There are links to types of energy and also simple explanations to how photosynthesis is the starting point of the food chain. This site also tells us that because of our eating habits, we are in two food chains- marine and land.

Plants that have photosynthesis are supplying us with the first product of the food chain. Not only that, they are the source for oxygen, the food we eat, our clothes, and even our furniture, among other things. Plants also remove greenhouse gas from the air, provide habitat to many animals.

Therefore we should understand the ecology of the environment with respect to plants. What is their number in terms of individuals (the population), and with respect to other living beings in the environment. Go to this page to see where plants are placed with respect to other living organisms.

In typical grassland, for example, the plants outnumber all other levels in the pyramid combined. However in the forests, other living organisms compete for space with plants. But a balance is maintained in the ecosystem.

There may be special relationships that have evolved within the community in which one particular species grows in obligate association with one other particular species, upon which still others depend. This site explores such relationships.

Presentation on theme: "What's for dinner? Exploring a Food Web."— Presentation transcript:

1 What's for dinner? Exploring a Food Web

2 Let’s Review…

3 Herbivores Some animals do not eat other animals. They survive on plants and are known as “herbivores”.

4 Carnivores Some animals, like the kingfisher, eat only other animals. These animals are called “carnivores”.

5 Omnivores Some animals, like us, eat both plants and animals.
These animals are called “omnivores”.

6 Consumers “Consume” means “eat”.
Animals are consumers because they “eat” (consume) food provided by plants or other animals.

7 Producers Plants are living organisms. They need nourishment to survive. But… Plants do not eat other plants or animals. Plants are called producers, because they produce their own food using sunlight.

8 The fly is eaten by the thrush.
Food Chains A food chain shows what is eaten. The fly is eaten by the thrush.

9 Food Chains A food chain shows what is eaten.
The lettuce is eaten by the rabbit.

10 Food chains always start with a plant.
The lettuce is eaten by the slug, the slug is eaten by the bird.

11 Food Chains - a Reminder
A food chain shows which animals eat other animals or plants. Plants don’t eat things. A food chain starts with what gets eaten and the arrows point towards what does the eating. Food chains only go in one direction.

12 Where do the arrows point?

13 The top of the food chain.
Some animals are said to be at the top of the food chain. This is because they are not hunted by other animals. No other animal hunts the lion. The lion is at the top of the food chain. Can you think why?

14 Food Webs In the wild, animals may eat more than one thing, so they belong to more than one food chain. To get the food they need, small herbivores may eat lots of different plants, and carnivores may eat many different animals.

15 Food Webs We can show this by using a food web, which is just a more complicated version of a food chain. fox owl rabbits mice grass seeds berries

16

17 Let’s do the following together. Answer the questions in your notebook.

18 Take a look at the Food Web. 1. Which organisms are the producers?
_________________ _________________ 2. Identify the consumers... C – Carnivore O – Omnivore H – Herbivore

19 1. Which organisms are the producers
1. Which organisms are the producers? Answer: Cacti, Bushes, Flowers, Ocotillo, Rabbit Brush, Sage Brush, etc. 2. Identify the consumers... C – Carnivore O – Omnivore H – Herbivore Answer: C-=Tarantulas, Scorpions, Lizards, Snakes, Fox, and Hawk. O = Lizards H = Insect, Rodents, Kangaroo Rats.

20 3. What would happen if the rodents and kangaroo rats died due to a severe drought?

21 The snake would only have one food choice left, lizards
The snake would only have one food choice left, lizards. Also, it would give less choices for the fox and hawk to eat, making them compete for what is left.

22 4. Use one or two blank pages in your notebook for the following
4. Use one or two blank pages in your notebook for the following. Draw a simple food chain in your notebook. Add arrows to show the transfer of energy. See if you can add another food chain to make it a food web. How many can you add? Remember – Arrows go to the organism that does the eating! Arrows show the direction the energy has transferred! For example, the plants energy goes to the caterpillar and the caterpillar goes to the bird.

23 5. After you have finished your food web answer these questions.
What would happen to your food web if the plants, died because of a flood? What would happen if a disease affected the top of your food chain?

24 Breaking the Chain Organisms living in a habitat depend on each other.
If one part of a food chain dies out or is greatly reduced, the consumers have to find alternative food, move away, or starve.

25 Environmental Changes?
There are lots of reasons why environmental changes affect animals. The most common are: loss of habitat (woodlands cut down, rivers drying up, number of people in the world is growing at an alarming rate). chemicals or pollution poison the animals. hunting (for sport, their fur, tusks or meat).

26 Caring for the Environment
It is in our own best interest to look after the world we live in. If a habitat is lost or damaged, it has an effect on everything else, even if we do not see or understand it right away. Remember - once something is gone, it’s gone forever!

What are 3 food chains in a food web?

What travels through food chain or web?

What are food chains and food webs give examples?

What are the 4 food webs?