SCIENCE – FORM TWO FOOD WEBs & FOOD CHAINs Created by: Alison Ong EVALUATION ACTIVITIES VIDEO CONTENTS
WHAT IS A FOOD CHAIN ?
A shows how each living
thing gets its food. Some animals eat plants and some animals eat other animals.
EXAMPLE OF A FOOD CHAIN
A food web is a model that shows all the possible feeding relationships between organisms living in an ecosystem.
What are the differences between food webs and food chains?
A food web is actually several food chains joined together.
How many food chains can you make from this food web?
WHAT IS IN A FOOD CHAIN ?
Plants get their energy from the sun. They are producers because they make their own food using energy from the sun.
Consumers hunt, gather, and store food because they cannot make their own.
Three Types of Consumers Omnivores Herbivores Carnivores
A herbivore is an animal that gets its energy from eating plants.
Large Herbivores Medium-sized Herbivores Small Herbivores
A carnivore is an animal that gets food from killing and eating other animals.
Large Carnivores Medium Carnivores Small Carnivores
An omnivore is a kind of animal that either eats other animals or plants.
Medium-sized Omnivores Small Omnivores
Decomposers and scavengers
Let’s Look at a Food Chain
A food chain is a simplified way to look at the energy that passes from producers to consumers.
1. Which is not a food chain?
A Grass Grasshopper Mouse Snake
B Green plant Snail Rat Eagle
C Grasshopper Mouse Snake Hawk
D Green plant Rabbit Hawk
The above diagram shows a ________. A food chain B food web C food pyramid D food organizer 3. How many food chains are there in the food web in the above diagram? A 1 B 2 C 3 D 4
4. The above diagram shows organisms W, X, Y and Z involved forming a food chain. Which of the following arrangements show the right sequence?
A Y Z X W
B Y Z W X
C Z Y W X
D Z W X Y
5. The above diagram shows energy circles in a food chain. What does X, Y and Z represent ? X Y Z A Consumer Primary consumer Secondary Consumer B Primary consumer Secondary Consumer Tertiary consumer C Producer Primary consumer Secondary Consumer D Producer Secondary Consumer Tertiary consumer
6. The above diagram shows the numbers of organisms in the energy pyramid. At the apex is the A carnivore. B herbivore. C omnivore. D producer. 7. A ________ is a sequence of consumption and represents energy transfer through the environment. A food chain B food web C food pyramid D food organiser 8. The chart in the above figure shows a food chain. What do P, Q and R represent? P Q R A Rabbit Falcon Snake B Rabbit Snake Falcon C Snake Rabbit Falcon D Falcon Snake Rabbit
9. The above diagram shows a food web. If all the snakes die, what happens to the population of the frog? A The population of frogs will increase very fast. B The population of frogs will decrease very fast. C The population of frogs will die, too. D The eagle will die because there is no more food left. 10. In the above food relationship, where the grasshopper eats the green plants and the frog eat the grasshopper.......... A the frog is the prey and the grasshopper is the predator. B the frog is the predator and the grasshopper is the prey. C the frog is the primary consumer. D the grasshopper is the tertiary consumer.
http://video.search.yahoo.com/search/video;_ylt=ArqfNUQJzeegttPYVGc.PzGbvZx4?vc=&p=food+webs+and+food+chains&toggle=1&cop=mss&ei=UTF-8&fr=yfp-t-405 Link To Video of Food Webs and Food Chains http://www.google.com.my/#sclient=psy&hl=en&tbm=vid&source=hp&q=food+webs&aq=f&aqi=&aql=&oq=&pbx=1&fp=fecb92ac9f54125e&biw=792&bih=425 http://www.google.com.my/#sclient=psy&hl=en&tbm=vid&source=hp&q=food+webs+and+food+chains&aq=0&aqi=g1&aql=&oq=food+webs+and+&pbx=1&fp=fecb92ac9f54125e&biw=1024&bih=571 http://www.slideshare.net/reaofsun/food-chains-webs-presentation http://www.slideshare.net/sth215/food-chains-and-food-webs-259481