Page 146 - Knowledge Organiser Yr8 24-25

Knowledge Base: Science 8.9 Ecosystems Year 8
5. Food webs and interdependence
5.1
Define the term ecosystems
An ecosystem is all the living organisms interacting with their physical environment
5.2
Define the term interdependence
When organisms in an ecosystem depend on each other for resources
5.3
What is a food web?
It shows how all organisms in an ecosystem interact
5.4
Explain why a food web is made up of many food chains
Most consumers eat more than one organism in an ecosystem
5.5
Name the producers in the food web below
Plants
5.6
Name the carnivores in the food web below.
Ground beetles and Centipedes
5.7
Explain why the slug population might decrease if a disease wiped out snails
Because Ground Beetles would not have as many snails to eat and would eat more slugs.
5.8
Explain why the slug population might increase if a disease wiped out snails
Because Snails would not be eating the plants so Slugs would have more food.
6. Pollination and food security
6.1
What is pollination?
The process where pollen is transferred to the female organs of a plant, to enable seeds to be made
6.2
What is food security?
The whole population having access to a sufficient quantity of affordable & nutritious food
6.3
Why are producers important?
All consumers, including humans, depend upon producers for their food.
6.4
Why is pollination important?
We depend upon pollination by insects (including the honey bee) for many of our crops. Without them, the security of our food would be threatened
6.5
Why have bees and other pollinating insect populations declined in the last 50 years?
• Destruction of insect habitats • Pests
• Diseases
• Use of insecticides
6.6
What are some factors that can effect food security?
• Rising food prices
• Increased cost of farming
• Conflict in some parts of the world
• Increasing human population
• New pests & pathogens affecting farming
• Changing diets
• Environmental changes
7. Bioaccumulation
7.1
State 4 changes that might affect the organisms in an environment
A new predator, habitat destruction, use of pesticides, pollution.
7.2
What is pollution?
The release of harmful or poisonous chemicals called toxins into the environment.
7.3 State 3 types of pollution Land, water, air
7.4
What is bioaccumulation?
The increasing concentration of toxin from one trophic level to the next trophic level up.
Example of a food web
7.5 Give 3 examples of harmful toxins Insecticides, mercury, microplastics
146