The World of Tardigrades (Middle School)
- Grade Level:
- Middle School: Sixth Grade through Eighth Grade
- State Standards:
- North Carolina Essential Standards Grade 7 Science 7.L.1.2
In this field trip, middle school students will be introduced to the microscopic world that thrives in lichens including Tardigrade characteristics, the Great Smoky Mountains National Park’s All Taxa Biodiversity Inventory and man-made threats. This packet is broken into three parts including activities at the park, a preparation activity and two wrap-up activities.
There is a microscopic world around us that few people are fortunate enough to explore. In this unit, we will discover the hidden world inside a collection of lichens. Using a simple lab extraction method, we will isolate Tardigrades, Rotifers, Nematodes, Water mites and possibly other creatures. This activity pairs well with our Lichen Monitoring study and both units together explore the impacts of acid deposition on lichens and the fascinating world that lies within. These activities specifically introduce students to Tardigrades and the terminology used to describe them.
1) understand the biodiversity of the Great Smoky Mountains National Park
2) learn several characteristics of Tardigrades
3) explain what is meant by an extremophile
Step 1: When students visit the Smokies on their field trip they will be collecting, isolating, and viewing tardigrades. This lesson will introduce tardigrades and their characteristics. Read aloud to the students the following information regarding the ATBI and Tardigrades. Students should read individually the vocabulary and definitions worksheet and tardigrade information worksheet. After the students have finished their reading, discuss the characteristics of tardigrades and what adaptations they have in order to live in extreme environments.
Step 2: To view the Biodiversity podcast video go to
http://www.thegreatsmokymountains.org/eft/10modules.html Turn the microscope knob that appears on the computer screen to Section 1, Understanding Biodiversity. Click "Watch Video" and view video.
Students can create a concept map for the subject of "tardigrades" before starting the series of lessons. They can create a second concept map for comparison after the lessons. Did students show any gains in their organization of their knowledge; the use of concepts, content and terminology and connections; and knowledge shown between the relationships of concepts. Please see our concept map scoring rubric for grading guidance.
When most students imagine national parks and nature in general they probably think of large animals such as bear and deer. Although bear, deer, and other visible animals are important parts of the ecosystem, there are other important pieces that we often overlook. Tardigrades and other microorganisms are some of the most numerous and most biodiverse organisms on Earth. This unit explores the biodiversity of these microscopic organisms and the threats to some of their preferred habitats.
Bilateral symmetry: symmetrical arrangement, as of an organism or a body part, along a central axis, so that the body is divided into equivalent halves.
Cryptobiosis: the metabolic state some organisms enter in response to adverse environmental conditions such as freezing, drying, or oxygen deficiency. In this state, all metabolic processes stop, preventing reproduction, development, and repair until environmental conditions return to being hospitable. When this occurs, the organism will return to its metabolic state of life as it was prior to cryptobiosis.
Eutardigrada: a class of Tardigrada without lateral appendices. These species are primarily found in lichens, mosses, and leaf litter, but many species are found in freshwater habitats such as lakes, rivers, and streams.
Extremophile: an organism that thrives in and even may require physically or geochemically extreme conditions that are detrimental to the majority of life on Earth.
Heterotardigrada: a class of tardigrades comprised of two orders: the armored terrestrial tardigrades and the marine tardigrades. Heterotardigrades have a lateral appendage between the head and the shoulder plate.
Meiofauna: animals inhabiting the bottom of a river, lake, or sea that are nearly invisible to the naked eye with dimensions in the range 0.1 to 1 mm.
Micrometazoa: extremely small multicellular animals.
Parthenogenesis: form of reproduction in which an unfertilized egg develops into a new individual; no males are present in the population.
Polyextremophiles: an organism which has several extremophilic features.
Tun: cryoptobiotic state of the tardigrade in which the appendages are drawn inward and metabolism stops.