LS2+(7-8)+-+6


 * Students demonstrate an understanding of energy flow in an ecosystem by …**

6a __explaining the transfer of the sun’s energy through living systems and its effect upon them.__

6b describing the basic processes and __recognizing the names and chemical formulas of the substances__ involved in photosynthesis and respiration.

6c __explaining the relationship__ __between photosynthesis and__ __respiration__.

**Students demonstrate an understanding of food webs in an ecosystem by …**

6d creating or interpreting a model that __traces the flow of energy in a food web__.

What do these GSEs mean? What subtopics do students need to address to understand these GSEs?
6a) Students need to be able to explain the basis of energy flow (energy cannot be created or destroyed) Students need to address the characteristics of living things (living things need to grow, reproduce, use energy etc). 6b) Students need to be able to describe photosynthesis and respiration in their own words.Students need to understand the plant cell (chloroplasts, chlorophyll and mitochondria and what occurs there) Students need to know the chemical formula for all of the substances involved in respiration and photosynthesis (water H20, carbon dioxide C02, oxygen 02, and glucose C6H12O6 ) Students need to understand how to read a basic chemical equation (products, reactants and interpreting the arrow) 6c) students also need to know that photosynthesis and respiration are reversible reactions (the products of one equation are the reactants of the other) This symbolizes the balance of life on earth and the interdependence. 6d) Students need to understand the vocabulary involved in the foodweb/flow chart and be able to explain them in their own words (example: herbivore, carnivore, producers, consumers etc.)

What ideas to students need to understand before they can address the topics described above?
6a&c) Students need to demonstrate an understanding of the characteristics that distinguish between living and nonliving things. Students should also be able to demonstrate an understanding of the key components that most organisms require for life on this planet (food, water ect.) Students should be able to explain what organisms directly use the sun for energy and how this process works (example: photosynthesizing plants). 6b &c) Students need to understand how to read a basic chemical equation (products, reactants and interpreting the arrow) Students need to understand the difference between autotrophs and heterotrophs and that plants are autotrophs Students need to understand what a chemical process is Students need to know what all cells need to live

What misconceptions are students likely to have about these topics?
6a) Students may confuse living with nonliving organisms. 6b) Students often have the misconception that plants grow from sunlight, water & soil. Students often think that plants get food from their environment (ie soil) instead of understanding that plants manufacture their own food as part of a chemical process 6c) Students may have a difficult time understanding the process of photosynthesis and respiration, students may think plants use only photosynthesis and animals use only cellular respiration Photosynthesis and respiration cycle does not necessarily occur in the same cell or even in the same organism 6d) Misconceptions may arise when students investigate species that may gain energy across multiple tropic levels or that may oppose the flow of the trophic levels. Students also need to understand that many species obtain energy from the sun INDIRECTLY by consuming other organisms that rely on the sun's energy for life.

What phenomena and representations help students understand these topics?
6a&d) A tropic level flow chart may help students understand this phenomena. A web diagram of how the sun provides energy to organisms; starting with organisms that use sun directly for energy and ending with organisms that consume other organisms for energy. []
 * Doyle, at the Science Teacher Blog, argues that it is important for students to see plants grow before they can understand the details of photosynthesis. If you agree with this, please add your strategies for integrating observations of living plants into your course.
 * 6b) Photosynthesis representation [] This site shows a representation of photosynthesis to better help students understand the concept Cellular respiration representation []
 * 6c)Students may benefit from designing a graphic organizer showing what products go in where the process occurs and what products come out to visualize the cycle of photosynthesis and respiration

What activities or activity sequences can be used to address these GSEs?
6 b&c)Physical models and represent the process of photosynthesis and cellular respiration. Then students could physically act out and visually see the process.[] An Inquiry based activity built around the concept of photosynthesis and cellular respiration. []

Related NECAP Items

 * NECAP 2008 Gr 08 09
 * NECAP 2008 Gr 08 09 Analysis

Relate Web Resources
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