Why are algae toxic, anyway?
Begin with the question: Why do organisms secrete toxins? Two video clips are shown, one of which shows the prey ( S. major) being eaten by K. micrum. The other clip shows the prey escaping.
Objectives
The learner will:
  • Predict the behavior of K. mircrum and it's prey, S. major.
  • Hypothesize why microorganisms would be secrete toxic byproducts
  • Describe the predator/prey relationship between the two organisms
  
Materials
Procedure
1.  Show the clips of the prey being eaten and the clip of the prey escaping.
2.  Point out that the size of the prey is about 1/2 of the size of K. micrum, which is like an adult human trying to eat something the size of a 5 year old.
3.  The students may draw many conclusions about the use of toxins including: To capture prey, to escape prey or it is simply a byproduct of metabolsim.
4.  In this case, evidence suggests that K. micrum secretes a toxin to capture prey.
References
Clips courtesy of Jason Adolf, Center of Marine Biotechnology 
State Standards
1.2.2- The student will pose meaningful, answerable scientific questions.(NTB)
3.2.2- The student will conclude that cells exist within a narrow range of environmental conditions and changes to that environment, either naturally occurring or induced, may cause changes in the metabolic activity of the cell or organism.
3.5.2- The student will analyze the interrelationships and interdependencies among different organisms and explain how these relationships contribute to the stabilty of the ecosystem.
3.5.4- The student will illustrate how all organisms are part of and depend on two major global food webs that are positively or negatively influenced by human activity and technology.
6.2.1- The student will explain how organisms are linked by the transfer and transformation of matter and energy at the ecosystem level. At least — Photosynthesis/respiration Producers, consumers, decomposers Trophic levels Pyramid of energy/pyramid of biomass
6.2.4- The student will provide examples and evidence showing that natural selection leads to organisms that are well suited for survival in particular environments. At least — coevolutionary relationships, e.g. symbiotic relationships variation within a species increases survival potential natural selection provides a mechanism for evolution adaptations of organisms within biomes
Lesson Resources
Clip of prey escape
Clip of prey injestion