Students will understand that living organisms interact with one another.

Standard 1: EcologyStudents will understand that living organisms interact with one another

Standard 1: Ecology

1. Objective 1: Summarize how organisms interact with one another and their environment.

1. Objective 1: Summarize how organisms interact with one another and their environment.

A. Arrange components of a food chain according to energy flow.

Autotroph – organisms that collect their own energy from sunlight or inorganic substances.

Photos from the flower conservancy at Golden Gate Park

Heterotroph – organisms that must consume other organisms to get energy.

Herbivore – an organism that eats only plants.

Carnivore – an organism that eats only other heterotrophs.

Calypso and Simba Predation of wildlife by domestic cats Felis catus in Great Britain

Omnivore – an organism that eats plants and other heterotrophs.

Carnivorous autotrophs?

Pitcher plant

Models of Energy Flow• The source of energy is the Sun.• Plants and other autotrophs are the producers. They take in the

energy from the sun and store it as food (sugars).• First level consumers, herbivores and some omnivores, take in

their energy from the producers.• Second level consumers prey upon the first level consumers,

they are carnivores and omnivores. • Third level consumers, and beyond, represent the top of the food

chain. They are the top or apex predators of a habitat and can be carnivores or omnivores (such as Canis lupus or Homo sapien sapien)

Detritivore – an organism that feeds on plant detritus, pieces of organic dead matter and waste.

• Trophic level – each step in a food chain or food web.

3rd level consumer

2nd level consumer

1st level consumer

3 Producers

Food chain – a simplified model that shows the energy flow through an ecosystem.

Food web – model that shows many interconnected food chains and pathways in which energy and matter flow through an ecosystem.

Energy flows through a food chain from the Sun → producers → 1st level consumer → 2nd level consumer → 3rd level consumer.

Standard 1: Ecology

1. Objective 1: Summarize how organisms interact with one another and their environment.

A. Arrange components of a food chain according to energy flow

B. Compare the quantity of energy in the steps of an energy pyramid.

Biomass – total mass of living matter at each trophic level

• Most energy at each trophic level is used up as cellular respiration and other metabolic processes which then is released out into the environment as heat.

• Only a small amount (10%) of energy is passed on to the next trophic level.

10% of the available energy passes to the next level of the energy pyramid.