TEK 7. 13(13) Organisms and environments TEK 7.13(13) Organisms and environments. The student knows that a living organism must be able to maintain balance in stable internal conditions in response to external and internal stimuli. The student is expected to: investigate how organisms respond to external stimuli found in the environment such as phototropism and fight or flight; and describe and relate responses in organisms that may result from internal stimuli such as wilting in plants and fever or vomiting in animals that allow them to maintain balance. Big Ideas: 1)  Organisms respond to both internal and external stimuli. 2)  Internal stimuli include hunger, thirst, hormones. 3)  Thirst is a mechanism essential to maintaining fluid balance within an organism. 4)  Hunger is triggered by a release of a hormone in the brain. 5)  External stimuli include presence or absence of heat or light.

Texas Essential Knowledge and Skills Statement: The student knows that a living organism must be able to maintain balance in stable internal conditions in response to external and internal stimuli. 1. Organisms respond to changes in the external environment in order to maintain balance. We call this balance homeostasis. The change in the external environment is called a stimulus, and the resulting reaction of the organisms is called a response. 2. Plants may respond to an external stimulus such as touch, gravity (gravitropism), and light (phototropism). 3. An animal may respond to an external stimulus, such as the presence of a predator by becoming aggressive or running away (fight or flight). 4. Organisms have an internal announcement system to alert them of hunger, thirst, and temperature extremes to maintain homeostasis. 5. Plants may respond to an internal stimulus such lack of water or other nutrients by either wilting or changing its growth/development. 6. Animals respond to internal stimuli in various ways. Animals will vomit when food is spoiled or contaminated. When pathogens like bacteria or virus invade humans, the body responds by releasing chemicals to raise the core body temperature, causing a fever.

1. What is the difference between a stimulus and a response? Student Expectation: The student is expected to investigate how organisms respond to external stimuli found in the environment such as phototropism and fight or flight and describe and relate responses in organisms that may result from internal stimuli such as wilting in plants and fever or vomiting in animals that allow them to maintain balance. 1. What is the difference between a stimulus and a response? 2. How does changing an external stimulus affect how an organism will respond? 3. In what ways does an organism’s body respond to maintain homeostasis? 4. How do organisms respond internally when unknown pathogens invade the body?

an internal warning system to Organisms have alert them of ________, _______, and ______________ extremes to maintain ______________. burn __________ to Our bodies keep up with our ___________ needs. ________________ helps maintain a stable body temperature of about 98.6°F. The ________________ of sweat returns the body to its original temperature. If an organism feels threatened by an external stimulus, such as a predator, it responds by ____________ or _______________ _________.

Warm up Stand up and balance on one foot for 3 minutes. After the timer goes off, sit back down in your seat. Discuss the following questions with your table partners: What did you notice during this activity? Did it get more difficult to balance as time went on? What did you want to do? You just experienced homeostasis. Your body was trying to keep you upright by maintaining your balance. Homeostasis is regulated by the nervous system.

HOMEOSTASIS Output Input Cause Effect Stimulus Response Balance Organisms respond to changes in their environment in order to maintain balance. We call this balance homeostasis. Example: The stimulus is being struck with the hammer. Example: The response is the knee jerk reflex. Change Reaction Output Input Cause Effect Stimulus Response Balance HOMEOSTASIS

Homeostasis (Balance) Complete the “Stimulus” column on your chart. Response Homeostasis (Balance) 1. Hunger 2. Thirst 3. Excess body heat 4. Low body temperature 5. Increased Exercise 6. Spoiled Food 7. Bacteria or Virus 8. Predator 9. 10. 11. Complete the “Stimulus” column on your chart. You have 2 minutes. 1 2 2 1 5 4 3 6 7 8 9 2 5 6 4 3 1 5 8 4 5 3 2 1 6 7 2 3 1 7 9 4 1 9 1 8 7 5 6 2 3 8 9 7 6 4 5 8 4 3 4 2 9 3 5 1 2 6 9 7 8 Minutes Seconds

Homeostasis (Balance) Complete the “Stimulus” column on your chart. Response Homeostasis (Balance) 1. Hunger 2. Thirst 3. Excess body heat 4. Low body temperature 5. Increased Exercise 6. Spoiled Food 7. Bacteria or Virus 8. Predator 9. 10. 11. Complete the “Stimulus” column on your chart. You have 2 minutes. 2 5 3 1 4 6 7 8 9 2 5 6 4 3 1 5 9 4 5 3 2 1 6 7 2 3 1 8 7 4 9 1 8 7 5 6 2 3 8 9 7 6 4 5 8 4 3 4 2 1 9 3 5 1 2 6 9 7 8 Minutes Seconds

extremes to maintain homeostasis. Organisms have an internal warning system to alert them of hunger, thirst, and temperature extremes to maintain homeostasis.

YELLOW – Our group has a question/ RED – HELP! Our group has a question/problem and we can’t move on until it’s solved! YELLOW – Our group has a question/ problem and we can keep working while we’re waiting for help. GREEN – No questions or problems at this time. Yay!

Use your prior knowledge of HOMEOSTASIS, EQUILIBRIUM, and BODY SYSTEMS to complete the “Response” and “Homeostasis/Balance” columns for the first four stimuli on your chart. 04 19 20 18 16 21 17 23 27 28 26 25 15 24 22 13 04 05 03 02 00 01 06 07 11 12 10 09 08 14 29 50 51 49 48 46 47 52 53 58 59 57 56 54 55 30 45 35 36 34 33 31 32 44 37 42 43 38 41 40 39 You and your table partners will have FIVE minutes to complete this task.

Use your prior knowledge of HOMEOSTASIS, EQUILIBRIUM, and BODY SYSTEMS to complete the “Response” and “Homeostasis/Balance” columns for the first four stimuli on your chart. 03 19 20 18 16 21 17 23 27 28 26 25 15 24 22 13 04 05 03 02 00 01 06 07 11 12 10 09 08 14 29 50 51 49 48 46 47 52 53 58 59 57 56 54 55 30 45 35 36 34 33 31 32 44 37 42 43 38 41 40 39 You and your table partners will have FIVE minutes to complete this task.

Use your prior knowledge of HOMEOSTASIS, EQUILIBRIUM, and BODY SYSTEMS to complete the “Response” and “Homeostasis/Balance” columns for the first four stimuli on your chart. 02 19 20 18 16 21 17 23 27 28 26 25 15 24 22 13 04 05 03 02 00 01 06 07 11 12 10 09 08 14 29 50 51 49 48 46 47 52 53 58 59 57 56 54 55 30 45 35 36 34 33 31 32 44 37 42 43 38 41 40 39 You and your table partners will have FIVE minutes to complete this task.

Use your prior knowledge of HOMEOSTASIS, EQUILIBRIUM, and BODY SYSTEMS to complete the “Response” and “Homeostasis/Balance” columns for the first four stimuli on your chart. 01 19 20 18 16 21 17 23 27 28 26 25 15 24 22 13 04 05 03 02 00 01 06 07 11 12 10 09 08 14 29 50 51 49 48 46 47 52 53 58 59 57 56 54 55 30 45 35 36 34 33 31 32 44 37 42 43 38 41 40 39 You and your table partners will have FIVE minutes to complete this task.

Use your prior knowledge of HOMEOSTASIS, EQUILIBRIUM, and BODY SYSTEMS to complete the “Response” and “Homeostasis/Balance” columns for the first four stimuli on your chart. 00 19 20 18 16 21 17 23 27 28 26 25 15 24 22 13 04 05 03 02 00 01 06 07 11 12 10 09 08 14 29 50 51 49 48 46 47 52 53 58 59 57 56 54 55 30 45 35 36 34 33 31 32 44 37 42 43 38 41 40 39 You and your table partners will have FIVE minutes to complete this task.

And For Understanding

Stimulus Response Hunger is an example of homeostasis Our bodies burn because food is something we need to keep our bodies balanced and healthy. Our bodies burn Food to keep up with our energy needs. When you are hungry a nerve sends a signal to your brain telling it that you need food. Stimulus Your brain sends a message to your stomach telling it to contract to signal that you are hungry. Response

Homeostasis (Balance) Stimulus Response Homeostasis (Balance) Hunger Eating Hunger pains are gone

Stimulus Response Thirst - A feeling of dryness in the mouth and throat. Signals go from the mouth and throat to the thirst center of the brain. Response The brain sends a signal to tell the body to drink water/fluids to maintain homeostasis.

Homeostasis (Balance) Stimulus Response Homeostasis (Balance) Thirst Drinking water/ fluids Body Fluid Balance

Muscle movement causes heat to build up (friction) and warm the body. HOMEOSTASIS and Body Temperature Stimulus Sweating helps maintain a stable body temperature of about 98.6°F. When we "heat up" we sweat. The evaporation of sweat returns the body to its original temperature. Response Muscle movement causes heat to build up (friction) and warm the body. Muscles shiver to create heat. Response Stimulus

Homeostasis (Balance) Stimulus Response Homeostasis (Balance) Excess Body Heat Low Body Temp. Stable body temperature Sweating Stable body temperature Shivering

Even more examples Stimulus + Response = HOMEOSTASIS

Increase in heart rate and respiratory rate HOMEOSTASIS Stimulus Response Increased Exercise Increase in heart rate and respiratory rate

Stimulus Response Homeostasis (Balance) Increased Exercise Increase in heart rate and respiratory rate. Normal O2 Levels in the blood

Fever or vomiting in animals allows them to maintain balance. HOMEOSTASIS Fever or vomiting in animals allows them to maintain balance. Stimulus Response Food Vomiting

Homeostasis (Balance) Stimulus Response Homeostasis (Balance) Spoiled Food Vomiting Wellness

Fever or vomiting in animals allows them to maintain balance. HOMEOSTASIS Fever or vomiting in animals allows them to maintain balance. Stimulus Response bacteria or viruses Fever

Homeostasis (Balance) Stimulus Response Homeostasis (Balance) Bacteria or Virus Fever Wellness

FIGHT or FLIGHT If an organism feels threatened by an external stimulus, such as a predator, it responds by fighting or running away.

Homeostasis (Balance) Stimulus Response Homeostasis (Balance) Predator Fight or Flight Threat Eliminated

Homeostasis (Balance) Stimulus Response Homeostasis (Balance) 1. Hunger 2. Thirst 3. Excess body heat 4. Low body temperature 5. Increased Exercise 6. Spoiled Food 7. Bacteria or Virus 8. Predator 9. 10. 11.

Use the three cards at your table to complete rows 9-11 on your chart. Identify the stimulus, response, and balanced state (homeostasis) for each example.

Turgor pressure is restored For Understanding Stimulus Response Homeostasis (Balance) Excess water in the body Excreted as urine. Balanced water levels Nightmare Fight or Flight Threat eliminated, Sleep restored Wilting plant Roots take up water from the soil and pass it up through the rest of the plant. Turgor pressure is restored

Notecard Knowledge 1. Answer to question #1 and your initials. Number your notecard 1-4 and write the title. Notecard Knowledge 1. Answer to question #1 and your initials. Pass your card to the right when instructed. 2. Answer to question #2 and your initials. Pass your card to the right when instructed. 3. Answer to question #3 and your initials. Pass your card to the right when instructed. 4. Answer to question #4 and your initials. Pass your card to the right when instructed. Compare and Share Notecards

1. Write one synonym for the word “stimulus”. 2. Which body system is responsible for regulating Homeostasis? 3. The Fight or Flight response is an example of an organism responding to an (internal or external) stimulus. 4. Write one synonym for the word “response”.

L1 1. Describe a situation where an organism responds to an external stimulus in order to maintain a state of balance, or homeostasis. 2. Describe a situation where an organism responds to an internal stimulus in order to maintain a state of balance, or homeostasis.

Directions: Fill in the blanks and complete the table below. Organisms respond to changes in the environment in order to maintain balance. We call this balance (1)____________. The change in the environment is called a (2)________, and the reaction of the organism is called a (3)_______. Homeostasis is regulated by the (4)________ system. Stimulus Response 5. Spoiled Food 6. Bacteria or Virus 7. Hunger