Gas Exchange in Plants (part of IB Topic B3.1)

◊ What are the similarities and differences in gas exchange between a flowering plant and a mammal?

Materials:

Self-Teaching Slides (SL)	Quizlet Vocab Set (Gas Exchange in Plants)
	Notes Template (SL)

IB Statement(s) and Objective(s)
B3.1.7: Adaptations for gas exchange in leaves Identify tissue layers of a leaf structure Outline the key adaptations for gas exchange in leaves, limited to waxy cuticle, epidermis, air spaces, spongy mesophyll, stomatal guard cells and veins. B3.1.8: Distribution of tissues in a leaf Draw and label tissue layers of a leaf B3.1.9: Transpiration as a consequence of gas exchange in a leaf Define transpiration Outline gas exchange that occurs through leaf stomata State the role of cohesion and adhesion in transpiration Describe 4 factors that affect the rate of transpiration Outline the effects of temperature, light exposure, humidity, and wind on the rate of transpiration B3.1.10: Stomatal density Define stomatal density Use a microscope to determine the stomatal density of a leaf tissue sample NOS Concept: Reliability of quantitative data is increased by repeating measurements Explain the need for repeated measurements (multiple trials) in an experiment Explain why standard deviation is used to summarize the spread of values State that error bars are a graphical representation of the variability of data Explain the need for controlled variables in experimental design

IB Statement(s) and Objective(s)

B3.1.7: Adaptations for gas exchange in leaves

Identify tissue layers of a leaf structure
Outline the key adaptations for gas exchange in leaves, limited to waxy cuticle, epidermis, air spaces, spongy mesophyll, stomatal guard cells and veins.

Outline the effects of temperature, light exposure, humidity, and wind on the rate of transpiration

Define stomatal density
Use a microscope to determine the stomatal density of a leaf tissue sample
NOS Concept: Reliability of quantitative data is increased by repeating measurements
Explain the need for repeated measurements (multiple trials) in an experiment
Explain why standard deviation is used to summarize the spread of values
State that error bars are a graphical representation of the variability of data
Explain the need for controlled variables in experimental design


Activities: ⓟ = podcast / ⍰ = inquiry 5 / ⓦ = Write it / Ӕ = The academy / Ⓡ = Read it
Ⓛ Lab: Measuring Transpiration with a Potometer (💁/ 👭 max 2) — *LAPTOPS AWAY!* Build your own potometer (there is enough information in the slides for how to do so). You may make it a short lab report, but you should include each of the following key parts: A clearly defined research question A clearly defined manipulated variable (Independent) A clearly defined responding variable (Dependent) Clearly outlined controlled variables A clearly described hypothesis – backed up with clear scientific reasoning A step-by-step method A results table – formatted with IV in the first column Keep in mind that a working potometers is quite difficult to build – attention to detail will make yours a successful one! Ⓛ (mini-lab): Stomata Under the Microscope (💁/ 👭max 2) Geraniums are everywhere in the Netherlands, and they also have leaves that have easy-to-see stomata under the microscope. Grab a geranium leaf and a microscope, and try to capture a photo of a stoma. One that is done, explain the function of the stomata in transpiration by answering: 1) How do stomata regulate the rate of transpiration?; 2) What is the relationship between stomata and xylem?; 3) What is the role of the stomata in the flow of water from roots to leaves? Extras: Old School Worksheet on Gas Exchange