Name _________________________________________________________ Plankton Wars! Plankton are organisms that drift; they cannot swim against prevailing ocean currents. Usually, plankton are very small, microscopic organisms, but some larger animals, like certain jellyfish, are also considered plankton. Plankton are divided into two groups, plants (phytoplankton) and animals (called zooplankton). Phytoplankton make their own food through photosynthesis (using sunlight to combine carbon dioxide and water into sugar), but zooplankton are heterotrophs and must ingest other organisms in order to get food. Plankton are usually heavier than water. This is important because if a planktonic organism just floated on the surface of the water, it might get too warm or experience too much light exposure from the sun and dry out. So, plankton tend to sink in the water column. However, phytoplankton need to stay where sunlight penetrates – in the Euphotic Zone (top 50 meters of the ocean). Many types of zooplankton feed on phytoplankton so they also need to stay in this zone. Both types organisms rely on adaptation to help prevent sinking. These adaptations include the following: -­‐Their small body size helps them remain lightweight. -­‐They increase the surface area of their bodies in order to increase drag and slow down sinking. Many phytoplankton have flattened bodies, spines, and other projections to slow sinking by adding surface area without increasing density. -­‐Phytoplankton also avoid sinking by forming chains with other cells, which also increases drag. -­‐The use of low-­density substances like oil or fat helps increase buoyancy and can serve as food reserves for some species. -­‐Some species of phytoplankton have flagella or cilia, which they use a motor to help them sink slowly. One thing to note is that many zooplankton are able to swim upward in the water column very slowly to maintain their position. However, if they sink too quickly or are too heavy, they will go straight to the bottom of the ocean and not be able to get back up. This requires energy, so any adaptations that help them stay in the Euphotic Zone help zooplankton to conserve energy. Phytoplankton do not have the same swimming ability as zooplankton, thus they are dependent solely on slow sinking adaptations to help them stay in the Euphotic Zone. Your task is to design a phytoplankton that sinks the slowest. You will be provided with materials and have three class periods to design and test your plankton Materials: • Yarn • 2 Paper clips • 1 Plastic bag • 4 Toothpicks • Tin foil • 2 Straws • 2 Popsicle sticks • 2 Rubber bands • 1 Index card • 30 cm of tape • A piece of an egg carton -­‐ The final day to test your plankton will be: Friday February 6. -­‐ Each person in your group will keep a daily journal that details modifications to your plankton design in words and pictures. -­‐ Each person will also turn in a typed response to the questions below – due Friday 2/6. While you may work together as a group to answer these questions, everyone must submit their own work. Response Questions -­ due Friday 2/6 Hard Copy 1. What are phytoplankton? What are zooplankton? How do these organisms fit into the ocean food web? 2. Why do phytoplankton and zooplankton need to remain in the Euphotic zone? Please specifically address both phytoplankton and zooplankton in your answer. 3. Why is it helpful for all types of plankton to have adaptations to prevent sinking? 4. Describe the design process and adaptations that you gave to your plankton over the course of this design challenge. What worked well? What did not work well? What can you conclude? By Friday 2/6, each person must turn in: __________________ Completed Plankton Wars Journal __________________ Labeled sketch of the final design of your plankton __________________ Typed, printed response questions Plankton Wars Journal Day 1 Brainstorming What did you accomplish in class on Wednesday 2/4? What does your plankton look like now? Why did you give the plankton the adaptations that you did? How well is your plankton floating? What do you need to do to make it better at floating? What did you accomplish in class on Thursday 2/5? What does your plankton look like now? Why did you give the plankton the adaptations that you did? How well is your plankton floating? What do you need to do to make it better at floating? Sketch and Label your FINAL design in the space below