LabLearner—The Science of Learning
LabLearner—The Science of Learning

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Photosynthesis

Investigation 3 – PreLab

 

 

 

 

 

 

 

Back to Investigation 3

ZERO-IN

Italicized font represents information to be shared orally or physically completed with the students at this time.

The non-italicized font represents additional information included to support the teacher’s understanding of the content being introduced within the CELL.

ASK WHY

Remind students that plants are all around us. We tend to take them for granted, but imagine a world without lush green grasses and trees – a planet blanketed in desert. Could we survive? Plants are an integral part of our environment and provide the food, oxygen, and fibers we depend on for survival. And their ability to photosynthesize is one of nature’s most amazing and essential phenomenons.

BRANCH OUT

Remind students that molecular plant geneticists track down genes to discover their functions and identify genes useful for creating improved plants. Their goal is to improve the production and quality of food and fiber. The genes they identify can be used in different ways, sometimes to create traits completely new to the species and other times to enhance traits that plants already have.

GET FOCUSED

Inform students that the Investigation is designed to help them to answer the following Focus Questions:

  • What is the importance of light in photosynthesis? Light is necessary for photosynthesis to take place.
  • In which parts of the plant does photosynthesis occur? Both the Elodea stem and the Elodea leaf contain chloroplasts; therefore, photosynthesis occurs in both stem and leaf.

Note: These questions are located in students’ SDRs at the beginning and end of the Investigation.

Note: These are succinct responses to the Focus Questions and are placed here for your reference at this time. Fully developed responses to the Focus Questions can be found on the PostLab page.

GO DEEPER

As a class, read the Background(s) in the Investigation. Have students read the information aloud or silently to themselves. When students have finished, discuss the following concepts as a class:

  • Green plants and other organisms carry out photosynthesis.
  • They use the energy of light and convert it to chemical bond energy of the sugars that are produced.
  • The chemical equation for photosynthesis is:

  • Plants use the chemical bond energy of the sugars as an energy source. This energy allows them to live and grow.
  • When animals eat plants, the bond energy is used in the same way.
  • Light from the Sun is needed for plants and other organisms to carry out photosynthesis. Without light, photosynthesis cannot occur.
  • Plants are made of different structures. Two of the main structures are the stem and the leaf. These are in turn made of smaller parts called cells.
  • One part of the cell which is important to photosynthesis is the chloroplasts.
  • Chloroplasts are located within a cell and contain chlorophyll.
  • Chlorophyll is the green pigment needed for photosynthesis.

Note: These concepts are integrated into the Background(s) and are used to deepen students’ comprehension of the big ideas.

LEARN THE LabLearner LINGO

The following list includes Key Terms that the teacher should introduce, as appropriate, within the CELL. These terms should be used, as appropriate, by teachers and students during everyday classroom discourse.

  • There are no Key Terms introduced in Investigation 3.

Note: Additional words may be bolded within the Background(s). These words are not Key Terms and are strictly emphasized for exposure at this time.

SET FOR SUCCESS

  • Ask students to imagine that they have to design an experiment investigating the effect of light on photosynthesis. Allow students to suggest a procedure that would answer this question.

Note: Encourage varied answers. Students may have suggested other methods such as placing a plant in a dark closet for a period of time while placing another plant in a sunny location for the same length of time and comparing the two plants. Such suggestions are appropriate responses.

  • Tell students that throughout this investigation they will find one way to explore the effect of light on photosynthesis. However, the way described is not the only way to perform such an investigation.
  • Play the video below. Stop to ask students questions or answer students’ questions when necessary. Remind students to follow along with their SDRs and make any notes that they think might be helpful.
  • After the video, direct students to divide into their lab groups to discuss their strategy for the lab. For example, they may assign certain group members to perform specific functions during the lab.

Note: The purpose of the video is to allow students to anticipate the laboratory experience they will soon encounter. Students should leave this PreLab session with a firm idea of what to expect and how to perform in the lab.

Note: Homework is posted below the video.

HOMEWORK

Tell students that they should review the Investigation in preparation for the Lab.