6.1 - Organisms and their environment

• Biologie
• Middelbare school
• havo, vwo
• Leerjaar 3

Welcome back!

- Looking back on the England trip!

- A sad message from yours truly :(

Ecology    Unit 6

6.1 Organisms and their environment

• You can classify the influences on organisms into biotic and abiotic factors.
  
• You can describe the levels of ecology.
  
• You can indicate the various feeding relationships in an ecosystem.

Environment

Environment: surroundings where an organism lives

Ecology: Study of relationships between organisms and their environment

Biotic factors: Influence that comes from living nature

Abiotic factors: Non-living influences of nature

To do now in silence

Write down three other examples of organisms which are influenced by (a)biotic factors.

Levels of ecology

1. Individual: An organism Ex: effect of temp on 1 elephant

2. Population: Group of individuals of the same species in an area. Ex: a group of Elephants living on a savannah.

3.Community: Populations of different species living together is an area. Ex: woodland: beech trees, ferns, earthworms, shrews (birds).

4. Ecosystem: Community and the biotope (abiotic factors) Woodland, pond, dunes, and meadows.

5. Biosphere: The part of the Earth where life is possible.

Food chain = a series of organisms in which each organism is the food source of the next. Each food source is called a link

Food chain: algae         water flea         perch         pike

Food web

-When food chains are interrelated

-form a network

-consists of living organisms

-producers, herbivores and carnivores

To do now in silence

Write down an example of a food web you would expect in the dutch dunes.

Example: Marine food web

Biomass = the total amount of high-energy substances in an organism

Organisms are composed of energy: carbohydrates(, proteins (15%) and fats (20%) = biomass

Biomass is contained in each level of a food chain.

Biomass decreases at each level of the food chain.

Energy is lost as heat and waste.

Accumulation of toxic substances in a food chain

Plants take up substance from their environment (CO2, minerals)

Also toxic substance - heavy metals

Ex. cadmium, mercury, lead, arsenic and tin

Animals eat the plants

Toxins get stored in fatty tissue of animals. 

Build up in the animals at the end of the food chain = accumulation

Why are animals at the end of the food chain at greater risk of dying?

What did we learn?

1. Abiotic vs. biotic factors
2. Levels of ecology
3. Food chain vs. food web
4. Biomass and accumulation 

To Do now in silence

Read 6.2 

answer 6.2 questions 18-25.

What level of ecology would you put all the organisms in a woodland?

1. Ecosystem
2. Community
3. Population
4. Individual

Which example describes a population?

1. All rabbits on Schiermonnikoog
2. The plants in a forest
3. All organisms in a pond
4. A lioness with her 2 cups in the savannah

What is a population?

1. An organism
2. a group of organisms of the same species, who reproduce together
3. All organisms in an area
4. All biotic and abiotic factors in an area

Pesticides and herbicides eventually show up in higher level consumers due to

1. climate change
2. accumulation
3. habitat destruction
4. soil erosion

Why is accumulation dangerous?

1. because animals eat more than they can digest
2. because plants can't do any photosynthesis
3. because in the top of a food pyramid chemicals built up to lethal levels
4. it causes an increase of biomass at each level of the food pyramid

Biotic factors

Abiotic factors