Biology
HS/Science
Unit: 04
Lesson: 02
Suggested Duration: 7 days
Homeostasis and Membrane Transport
Lesson Synopsis:
In this lesson, students investigate various types of membrane transport in cells and how these processes help maintain
homeostasis in the cell.
TEKS:
B.4
Science concepts. The student knows that cells are the basic structures of all living things with specialized parts
that perform specific functions. The student is expected to:
B.4B
Investigate and explain cellular processes including homeostasis, energy conversions, transport of molecules, and
synthesis of new molecules. Readiness Standard
B.11
Scientific concepts. The student knows that biological systems work to achieve and maintain balance. The student
is expected to:
B.11A
Describe the role of internal feedback mechanisms in the maintenance of homeostasis. Supporting Standard
Scientific Process TEKS:
B.1
Scientific processes. The student, for at least 40% of instructional time, conducts field and laboratory investigations
using safe, environmentally appropriate, and ethical practices. The student is expected to:
B.1A
Demonstrate safe practices during laboratory and field investigations.
B.1B
Demonstrate an understanding of the use and conservation of resources and the proper disposal or recycling of
materials.
B.2
Scientific processes. The student uses scientific methods during field and laboratory investigations. The student is
expected to:
B.2E
Plan and implement descriptive, comparative, and experimental investigations, including asking questions,
formulating testable hypotheses, and selecting equipment and technology.
Collect and organize qualitative and quantitative data and make measurements with accuracy and precision using
tools such as calculators, spreadsheet software, data-collecting probes, computers, standard laboratory glassware,
microscopes, various prepared slides, stereoscopes, metric rulers, electronic balances, gel electrophoresis
apparatuses, micropipettors, hand lenses, Celsius thermometers, hot plates, lab notebooks or journals, timing
devices, cameras, Petri dishes, lab incubators, dissection equipment, meter sticks, and models, diagrams, or
samples of biological specimens or structures.
Analyze, evaluate, make inferences, and predict trends from data.
B.2F
B.2G
B.2H
Communicate valid conclusions supported by the data through methods such as lab reports, labeled drawings,
graphic organizers, journals, summaries, oral reports, and technology-based reports.
GETTING READY FOR INSTRUCTION
Performance Indicator(s):
•
Using a model of a cell membrane, demonstrate examples of diffusion, osmosis, and active transport. For each
example, explain the movement of molecules in terms of homeostasis. (B.2E, B.2H; B.4B; B.11A)
1E; 3G;
5G
Key Understandings and Guiding Questions:
•
Different substances move across the cell membrane by diffusion, osmosis, or active transport to maintain
homeostasis.
— What are diffusion and osmosis?
— What is active transport and what are some examples?
— How do passive and active transport help a cell maintain homeostasis?
Vocabulary of Instruction:
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diffusion
osmosis
©2012, TESCCC
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passive transport
active transport
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homeostasis
ion/protein pump
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Biology
HS/Science
Unit: 04 Lesson: 02
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semi-permeable
membrane/selectively
permeable membrane
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endocytosis
exocytosis
Materials:
Refer to Notes for Teacher section for materials.
Attachments:
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Handout: Osmosis in Eggs (1 per student)
Teacher Resource: Osmosis in Eggs KEY
Handout: Cell Membrane Research (1 per student)
Teacher Resource: Cell Membrane Research KEY
Handout: Observing Osmosis in Elodea (1 per student)
Teacher Resource: Observing Osmosis in Elodea KEY
Handout: Cell Transport and Homeostasis Key Terms (1 per student)
Teacher Resource: PowerPoint: Cell Transport and Homeostasis Terms KEY
Handout: Osmosis Experimental Design Lab (1 per student)
Teacher Resource: Osmosis Experimental Design Lab KEY
Handout: Membrane Transport Movie Project PI (1 per student)
Teacher Resource: Performance Indicator Instructions KEY
Advance Preparation:
1. Prior to Day 1, locate a large graphic of the cell membrane to either print and display on a poster board or display
via a projection system in the classroom.
2. Prior to Day 1, arrange for access to student computers with Internet access.
3. Prior to Day 2, prepare the saline (salt) solution for the osmosis in Elodea lab. Prepare a 10% solution by mixing
10 g NaCl with 90 mL water. If you will need more than 90 mL, double or triple the recipe to make larger amounts.
4. Prior to Day 3, review the Teacher Resource: PowerPoint: Cell Transport and Homeostasis Key Terms to
insert any additional animations or graphics that may help your students understand the types of transport.
5. Prior to Day 5, prepare a 1% starch solution by adding 1 g of corn or potato starch to 99 mL of cold water. Bring
the mixture to a boil, and then allow it to cool. You can do this in a microwave. Multiply this recipe to make larger
amounts. You will need approximately 300–400 mL for every group.
6. Prior to Day 5, cut the dialysis tubing into lengths of 12–15 cm. You may also wish to pre-cut 6 inch pieces of
string. If you do not want to use string, you can also give students longer lengths of dialysis tubing, and they can
tie the tubing itself.
7. Prior to Day 6, obtain cell membrane models or print cell membrane graphics for each group of 3–4 students to
use during their Performance Indicator. Arrange for access to video cameras or other technology (smart phones)
for groups to record their assessment product. Consider providing access computers (1 per group) and movie
editing software, such as iMovie or Movie Maker (1 per group).
8. Prepare attachment(s) as necessary.
Background Information:
This lesson bundles student expectations that address cell structures and functions and the transport of molecules into
and out of the cell.
In the previous lesson, students identified cell structures and cell types. In this lesson, they will investigate homeostasis
and the movement of molecules in relation to the cell. This lesson provides a knowledge base crucial for subsequent
units. After this unit, students will learn about the specific cell structures and processes that operate in the context of
genetics, evolution, classification, viruses and bacteria, plants, and body systems.
STAAR Notes:
The transport of molecules is part of student expectation B.4B, which is a Readiness Standard on the STAAR Biology
Assessment. Transport of molecules will not be directly taught again before the test. The other student expectation in this
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Biology
HS/Science
Unit: 04 Lesson: 02
lesson, B.11A, is a Supporting Standard. Other than the content on transport of molecules, all student expectations from
this unit are reinforced in subsequent units before the test.
GETTING READY FOR INSTRUCTION SUPPLEMENTAL PLANNING DOCUMENT
Instructors are encouraged to supplement and substitute resources, materials, and activities to differentiate instruction to address the needs of learners.
The Exemplar Lessons are one approach to teaching and reaching the Performance Indicators and Specificity in the Instructional Focus
Document for this unit. Instructors are encouraged to create original lessons using the Content Creator in the Tools Tab located at the top of the page.
All originally authored lessons can be saved in the “My CSCOPE” Tab within the “My Content” area.
INSTRUCTIONAL PROCEDURES
©2012, TESCCC
04/29/13
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