Multicellular Organisms

Section 2.3

Animals

• Consumers – need to get energy from other organisms

predator – hunts other animalsprey – hunted by others for food

Animals

• Heterotroph – feeds on or eats other organisms

– Herbivores – feed on plants or algae– Carnivores – feed on other animals– Omnivores – feed on plants and animals

Digestion

• Process of breaking down food so that it may be absorbed by cells– Some organisms can take food directly into cells

(sponges)– Some have one opening for food to go in and

waste to go out (jellyfish)– Some have a tube-like system where food comes

in one way and waste goes out another (lion)

Digestion

• Physical and chemical activities are used to digest food (Chewing, churning,gastric juices)

Cellular Respiration

C6H12O6 + O2 CO2 + H2O + Energy

• Oxygen is usually taken in by respiratory system (spiracles, gills, lungs)

• Most animals can store food

Behavior

• Any visible response to a stimulus– Hunting– Drinking

• Can be inherited or learned– Weaving a spider web

(inherited)– Which organisms to avoid

(learned)

Categories of Behavior

• Individual– Meeting basic needs (obtaining food, shelter)

• Interactions between same species– Social behaviors (mating, working)

• Interaction between different species– Predation, commensalism, mutualism

Response to Seasonal Changes

• Migration– Movement of animals to a different region

• Hibernation– Sleeplike state that lasts for extended periods