Organisms have undergone Physiological adaptations that can be influenced by, or allow them to inhabit niche areas of the environment or their individual ecosystems.
What you intend the students to learn about this idea
Physiological adaptations can take two forms:
An organismic or systemic response of an individual to a specific external stimulus in order to maintain homeostasis.
A metabolic or physiologic adjustment within the cell, or tissues, of an organism in response to an environmental stimulus resulting in the improved ability of that organism to cope with its changing environment.
The break-down of this as relevant to the Unit 2 curriculum is:
Tolerance range of organisms- maintaining equilibrium by detecting and responding to changes in the environment.
Nerve control in complex organisms (multicellular): major sense organs and pathways of transmission of nerve impulses
Hormonal control in complex multicellular organisms ie: environmental influences towards sexual mutation in animal species and sunlight orientation in plants.
Regulating water balance and controlling temperature- ie: osmosis and diffusion, endothermic and exothermic organisms.
(VCAA, 2005)
Why is it important for students to know this?
Physiological adaptations allow animals to inhabit niche areas in environments and ecosystems. Unlike evolutionary adaptation which involves trans-generational adjustment, physiological adaptation is generally narrow in scope and involves response of an individual to a particular or specific, usually narrow, range of stimuli.
What else you know about this idea (that you do not intend students to know yet)?
That physiological adaptations displayed by a whole population have been achieved over time through the process of evolution.
Difficulties/Limitations connected with teaching this idea.
Physiological adaptations can be minuscule in nature but have far reaching affects.
Some physiological adaptations are resultant of a cause specific to an individual organism and are unable to be passed on to the next generation through reproductive means.
Knowledge about students' thinking which influences your teaching of this idea
Physiological adaptations are not unique to animals; plants can undergo them as well.
Other factors that influence your teaching of this idea.
Teaching procedures (and particular reasons for using these to engage with this idea).
Production of an Adaptation specific Glossary-
Students to create a glossary of terms specific to the Adaptation subject area. This would require them to look up those words directly relating to the topic and write a definition for them in their own words. This glossary could be expanded throughout the unit and used to revise at its conclusion.
Some of the terms applicable to physiological adaptation are:
Thermoregulation- the maintenance of internal body temperature within a tolerable range.
Immunity-resistance to infection. Torpor- a state of inactivity achieved by a vertebrate animal in which it allows its body temperature to dropXeropyte- a plant that has adapted to arid conditions. e.g. cactus Countercurrent exchange- the opposite flow of adjacent fluids that maximizes transfer rates; for example, blood in the gills flows in the opposite direction in which water passes over the gills, maximizing oxygen uptake and carbon dioxide loss. Tolerance range- the range of conditions that an organism can survive
Students work in groups to produce a short video, in stop motion style, regarding a physiological concept. Requirements- (per group)- Digital camera and tripod, laptop with "windows movie maker", plasticine, cardboard and other art materials.
Below is an example of a student made video explaining countercurrent exchange in a whale.
The production of a video requires students to think beyond merely understanding the process of the physiological concept in order to be able to explain it through the use of a medium other than words. IE: they are being required to do more than merely repeat the information they have learnt.
Temperature control experiment-
Maintaining a stable internal environment Purpose- To show the effect of exercise on pulse rate and on the rate of breathing and sweating. Requirements- (per group of students)
2 stop watches
Cobalt chloride paper
Forceps *For the extension activity
Clinical thermometer - one for each participant
2 buckets of hot water
2 buckets of cold water
Fan
Heater
Thermometer, -10° to 50°C Procedure- Work in a group of four. Two people are to measure and record, and two are to be the 'subjects' for the demonstration.
Both subjects are to sit quietly for three minutes. At the end of three minutes, the recorders measure and record the pulse rates, breathing rates and sweating rates of both subjects. (Measure the sweating rate by timing how long it takes a piece of chloride paper placed on the forehead to turn blue.)
Next, both subjects are to exercise vigorously for three minutes. STOP the experiment if a subject shows signs of stress. *line sprints (between two points), or steps (stepping up onto and down from a raised platform) are good activities for raising pulse rate.
At the end of three minutes the recorders again measure and record the pulse, breathing and sweating rates of both subjects.
Questions-
Why is it important that the same person observes the subject during this activity?
List the components from the internal environment that are used by cells particularly during exercise.
List the components of the internal environment whose levels increase during exercise.
Compare the results of the measurements made before and after exercise. Explain how the differences are related to our bodies maintaining a stable environment for our cells.
Extension- Investigate the effect of the external temperature on maintaining a stable internal environment.
Instead of the subjects exercising vigorously make one subject as cold as possible and the other as hot as possible (NOTE: relative to each other). Cooling could be achieved by removing some clothes, using a fan and placing extremities in cold water. Heating could be achieved by warming in front of a heater, donning extra clothing or by placing extremities in front of a heater.
Record ambient temperature, body temperature, sweating rate, pulse rate and behaviour at the beginning of, and at intervals throughout, the experiment. STOP the experiment whenever a subject shows signs of distress.
Explain your observations in terms of the body maintaining a stable internal environment
Washing of materials being used by students is of hygienic importance.
Check the relevant guidelines for students participating in experiments.
This practical experiment requires students to utilise what knowledge they have of physiology in relation to heart beat (pulse), perspiration and breathing rates as well as cellular metabolism. The write up of the practical component (lab report) combined with the questions requires the students to be able to combine this prior knowledge into a situation where aspects of all of them are coming into play.
Specific ways of ascertaining students' understanding or confusion around this idea (include likely range of responses).
Students understanding can be ascertained through their completion of the above tasks. Correction of both the glossary terms and of the practical experiment would both indicate varying levels of understanding relevant to physiological adaptation.
With the experiment in particular, students ability to eloquently explain their results and provide scientific reasoning for them are precise indicators of understanding. Practical reports can be used as an assessment piece, providing a measure of students understanding of this area and also indicating any areas which require further teacher input in order to clarify.
The production of the video requires students to demonstrate their understanding of a particular concept by visually displaying it for the viewing of others. The better their own understanding of the concept the better they are likely to be able to convey that understanding to others.
The break-down of this as relevant to the Unit 2 curriculum is:
- Tolerance range of organisms- maintaining equilibrium by detecting and responding to changes in the environment.
- Nerve control in complex organisms (multicellular): major sense organs and pathways of transmission of nerve impulses
- Hormonal control in complex multicellular organisms ie: environmental influences towards sexual mutation in animal species and sunlight orientation in plants.
- Regulating water balance and controlling temperature- ie: osmosis and diffusion, endothermic and exothermic organisms.
(VCAA, 2005)Production of an Adaptation specific Glossary-
Students to create a glossary of terms specific to the Adaptation subject area. This would require them to look up those words directly relating to the topic and write a definition for them in their own words. This glossary could be expanded throughout the unit and used to revise at its conclusion.Some of the terms applicable to physiological adaptation are:
Thermoregulation- the maintenance of internal body temperature within a tolerable range.
Immunity- resistance to infection.Torpor- a state of inactivity achieved by a vertebrate animal in which it allows its body temperature to drop Xeropyte- a plant that has adapted to arid conditions. e.g. cactus
Countercurrent exchange- the opposite flow of adjacent fluids that maximizes transfer rates; for example, blood in the gills flows in the opposite direction in which water passes over the gills, maximizing oxygen uptake and carbon dioxide loss.
Tolerance range- the range of conditions that an organism can survive
A full biology glossary is available online at: http://www.biology-online.org/
Stop motion videos-
Students work in groups to produce a short video, in stop motion style, regarding a physiological concept.Requirements- (per group)- Digital camera and tripod, laptop with "windows movie maker", plasticine, cardboard and other art materials.
Below is an example of a student made video explaining countercurrent exchange in a whale.
The production of a video requires students to think beyond merely understanding the process of the physiological concept in order to be able to explain it through the use of a medium other than words. IE: they are being required to do more than merely repeat the information they have learnt.
Temperature control experiment-
Maintaining a stable internal environmentPurpose- To show the effect of exercise on pulse rate and on the rate of breathing and sweating.
Requirements- (per group of students)
2 stop watches
Cobalt chloride paper
Forceps
*For the extension activity
Clinical thermometer - one for each participant
2 buckets of hot water
2 buckets of cold water
Fan
Heater
Thermometer, -10° to 50°C
Procedure- Work in a group of four. Two people are to measure and record, and two are to be the 'subjects' for the demonstration.
- Both subjects are to sit quietly for three minutes. At the end of three minutes, the recorders measure and record the pulse rates, breathing rates and sweating rates of both subjects. (Measure the sweating rate by timing how long it takes a piece of chloride paper placed on the forehead to turn blue.)
- Next, both subjects are to exercise vigorously for three minutes. STOP the experiment if a subject shows signs of stress. *line sprints (between two points), or steps (stepping up onto and down from a raised platform) are good activities for raising pulse rate.
- At the end of three minutes the recorders again measure and record the pulse, breathing and sweating rates of both subjects.
Questions-- Why is it important that the same person observes the subject during this activity?
- List the components from the internal environment that are used by cells particularly during exercise.
- List the components of the internal environment whose levels increase during exercise.
- Compare the results of the measurements made before and after exercise. Explain how the differences are related to our bodies maintaining a stable environment for our cells.
Extension- Investigate the effect of the external temperature on maintaining a stable internal environment.This practical experiment requires students to utilise what knowledge they have of physiology in relation to heart beat (pulse), perspiration and breathing rates as well as cellular metabolism. The write up of the practical component (lab report) combined with the questions requires the students to be able to combine this prior knowledge into a situation where aspects of all of them are coming into play.
With the experiment in particular, students ability to eloquently explain their results and provide scientific reasoning for them are precise indicators of understanding. Practical reports can be used as an assessment piece, providing a measure of students understanding of this area and also indicating any areas which require further teacher input in order to clarify.
The production of the video requires students to demonstrate their understanding of a particular concept by visually displaying it for the viewing of others. The better their own understanding of the concept the better they are likely to be able to convey that understanding to others.