Content Objective: Understand the concepts of food chains, food webs, trophic levels, energy pyramids, energy loss between trophic levels, heat loss in cell respiration, restrictions on trophic levels, primary production, and secondary production in ecosystems.
Language Objective: Communicate knowledge of trophic levels, energy pyramids, energy loss, heat loss, trophic restrictions, primary production, and secondary production using appropriate construction of food webs and food chains and using terminology and accurately describe the relationships and processes involved.
Syllabus Details:
C4.2.4 - Construction of food chains and food webs to represent feeding relationships in a community - "Represent relationships in a local community if possible. Arrows indicate the direction of transfer of energy and biomass."
C4.2.8 - Heterotrophs as organisms that use carbon compounds obtained from other organisms to synthesize the carbon compounds that they require - Students should appreciate that complex carbon compounds such as proteins and nucleic acids are digested either externally or internally and are then assimilated by constructing the carbon compounds that are required."
C4.2.10 - Classification of organisms into trophic levels- Use the terms “producer”, “primary consumer”, “secondary consumer” and “tertiary consumer”. Students should appreciate that many organisms have a varied diet and occupy different trophic levels in different food chains."
C4.2.11 - Construction of energy pyramids - "Students should use research data from specific ecosystems to represent energy transfer and energy losses between trophic levels in food chains."
"C4.2.12 - Reductions in energy availability at each successive stage in food chains due to large energy losses between trophic levels" "Decomposers and detritus feeders are not usually considered to be part of food chains. However, students should understand the role of these organisms in energy transformations in food chains. Consider the causes of energy loss."
"C4.2.13 - Heat loss to the environment in both autotrophs and heterotrophs due to conversion of chemical energy to heat in cell respiration - Include the idea that energy transfers are not 100% efficient so heat is produced both when ATP is produced in cell respiration and when it is used in cells."
C4.2.14 - Restrictions on the number of trophic levels in ecosystems due to energy losses - At each successive stage in food chains there are fewer organisms or smaller organisms. There is therefore less biomass, but the energy content per unit mass is not reduced.
C4.2.15 - Primary production as accumulation of carbon compounds in biomass by autotrophs - The units should be mass (of carbon) per unit area per unit time and are usually g m−2 yr−1. Students should understand that biomes vary in their capacity to accumulate biomass. Biomass accumulates when autotrophs and heterotrophs grow or reproduce."
C4.2.16 - Secondary production as accumulation of carbon compounds in biomass by heterotrophs - Students should understand that, due to loss of biomass when carbon compounds are converted to carbon dioxide and water in cell respiration, secondary production is lower than primary production in an ecosystem."
Activity 1
Activity 1 - Food Webs
1. Using the worksheet below. Make a list of all the animals and add three terms, one from each row below:
heterotrophs or autotrophs.
consumer, detritivores or saprotrophs.
producer, primary consumer, secondary consumer, tertiary consumer or decomposer.
2. Using the animals in the list create a food web of the animals. You can just use the names. You DO NOT need to print and cut out anything
Activity 2
Math fun! Using the link below, calculate the energy transfers for each trophic level and create a pyramid of energy. Please answer the questions on another document or on paper and upload to Google Classroom.
Activity 3 - Food Webs and Energy Webs
1. Using the worksheet from last lesson (Mr. C's awesome drawing!). Draw how the nutrients cycle in the ecosystem.
A. Strengthen Your Skills
B. Expand Your Knowledge