Organisms' Response to Environmental Stimuli
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Learn about how organisms respond to external and internal stimuli in their environment, including color changes and physiological adaptations. Discover how organisms gather information and adapt to survive.
Organisms' Response to Environmental Stimuli
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Presentation Transcript
Chapter 3, Lesson 4 How Do Organisms Respond to the Environment?
Stimulus and Response • Stimulus- a change in the environment of an organism that causes a response • Response- a reaction of an organism to a change in the environment.
Stimulus and Response • Responding to a stimulus (environment) is a life process. • An organism must be able to gather information about its environment before it can respond to changes
Stimulus and Response • External Stimulus: - Stimulus from outside the body Example: Weather Change • Internal Stimulus: - Stimulus from inside the body Example: Hunger and Thirst
Stimulus and Response • Ptarmigan Changes colors during different seasons to blend in with its surroundings. -In the spring they are speckled brown to blend in - In the winter they turn white to blend in with the snow
Ptarmigan • Stimulus= Weather Changes • Response= Feathers change colors
Gathering Information • An organism must be able to gather information about its environment before it can respond to changes • Organisms have unique sense organs that let them gather information • Examples:
Sharks • Eyes= see well in the dark • Nostrils= smell blood • Scale-covered openings= feel vibrations
Snakes • Tongues/Organs on roof of mouth= pick up scents • Heat detectors on lips or head= helps to find prey
Flies • Tiny hairs/feet= taste • Sensors on legs= for touch and temperature • Compound eyes= not clear, but easily detect movement
Physiological Adaptation Physiological Adaptation: Make it so an organism’s body parts can do a job in response to a stimulus.
Physiological Adaptation • Humans • Shivering= Physiological adaptation in response to the cold. The muscle contractions create heat. • Sweat= Physiological adaptation in response to the heat. Sweat glands become more active, the sweat evaporates and cools you down.
Physiological Adaptation • Seal -Stopping blood circulation to tail/flippers=Physiological adaptation to the cold water. This helps keep in body heat.