How can the Visual Thesaurus help students learn more about binomial nomenclature?
In this lesson, students will learn about the fundamental system of scientific classification: binomial nomenclature. Teams of students will compete in a binomial name scavenger hunt using the Visual Thesaurus and the online "Catalogue of Life" to identify two-part binomial names within specific genus categories.
Length of Lesson:
- learn the definition and origins of binomial nomenclature
- identify organisms by both binomial and common names
- use Internet resources to research binomial nomenclature
- white board
- computers with Internet access
- "Binomial Name Scavenger Hunt" chart [click here to download]
Defining binomial nomenclature through an example:
- Tell the class that you once spotted a "Helianthus giganteus" in your neighbor's garden. As your students puzzle over your sighting and wonder if you actually spotted Charlie Brown's "Great Pumpkin," display the Visual Thesaurus word web for the term "Helianthus giganteus" on the white board. Students will discover that "Helianthus giganteus" is just another name for the "giant sunflower" plant. (As a side note, you could also have students think about which roots in the binomial name could have led them to the plant's more common name [i.e., Helios (sun) and gigantic (giant)]).
- Explain to students that you initially had used binomial nomenclature to name the plant you had spotted in your neighbor's garden. Binomial nomenclature is the scientific system of classifying each organism by giving it a two-part name indicating its genus and its species (e.g., "Homo sapiens" is the binomial name for human).
- Type in just the term "Helianthus" in the VT to demonstrate to students that this capitalized first part of the binomial name indicates "genus" and is defined as "any plant of the genus Helianthus having large flower heads with dark disk florets and showy yellow rays"-in other words-"a sunflower" (point to the only other word on the word web diagram). Explain that although the species "giganteus" is not defined on the VT, that if students click on the definition of "Helianthus" on the meaning list, that the web display will reconfigure to reveal just how many different species of sunflowers (or Helianthus) there are.
Discussing the origins of binomial nomenclature:
- Ask students why they think there is a need in the scientific community for binomial nomenclature. If organisms already have common names such as "sunflower," why do we need an entirely different system of naming them?
- After eliciting students' responses to your question, establish that the binomial system of classification allows all species to be identified by the same two-part name by people around the world, therefore avoiding problems in translating names from one language into another. This system of scientific classification resulted largely from the work of the Swedish botanist Carl Linnaeus (1707-1778) who attempted to group all species in the natural world by shared physical characteristics (thus he is often referred to as "the father of taxonomy").
Setting up a "binomial scavenger hunt":
- Organize the class into small teams of three to four students each.
- Inform teams that today they will be competing in a scavenger hunt during which they will attempt to identify as many well-known species in particular genus categories by their binomial names as they can (in a limited amount of time).
- Explain to students that each team in the room will begin with a list of "genus" names and then they will be allowed to use two resources in their quest for binomial names: the Visual Thesaurus and The Catalogue of Life (an online index of the world's known species).
Modeling the scavenger hunt process:
- As an example, type the genus name "Meleagris" into the VT search box and display the resulting word web. Students will see that the genus "Meleagris" is comprised of "wild and domestic turkeys."
- Demonstrate for students the next step of trying to identify a binomial name within the genus "Meleagris" by using the Web site: The Catalogue of Life -- an online index of the world's known species. Show students that when they click on the "Search all names" option, they can type in the common name "wild turkey" into the search box to find its binomial name in the resulting list: Meleagris gallopavo (a binomial name developed by Linneaus in 1758). (Or, students can also find binomial names by using the "search for scientific names" option in the catalogue by typing in the genus name into this search box.)
Conducting a binomial name scavenger hunt:
- Distribute a "Binomial Name Scavenger Hunt" chart to each team [click here to download] and explain that the left-hand column of the chart contains a list of genus names that can be defined by using the VT. Then, it is each team's job to find one example of a species within that genus category that can be listed by its binomial name (middle column) and by its common name (right-hand column).
- Give teams a limited amount of time to research binomial and common names of organisms for their charts. Circulate around the room and assist teams if they are having difficulties using the VT and the The Catalogue of Life sites to conduct their research.
- Alert teams when their time is up and declare a scavenger hunt winner based on the number of accurate binomial and common names they have listed on the "Binomial Name Scavenger Hunt" chart.
Sharing binomial names:
- After the conclusion of the scavenger hunt, have each team share their findings. Students may wish to write their list of binomial names on the board and then have other teams guess these organisms' more common names.
- If time permits, you could discuss the process by which students discovered binomial and common names for each genus category. What confused or surprised them about certain genus categories? Which genus categories seemed to contain the most species variation? Which genus categories seemed to have the least species variation?
Extending the Lesson:
- One fun way to extend this lesson would be to conduct a follow-up "Binomial Bingo" game with the teams' findings. Each team could write its list of binomial names on the board while students make Bingo charts (with each of the 25 boxes containing one binomial name). Then, a student or teacher could call out the common names associated with particular binomial names and students could cross those binomial names off their boards. The first student with a row (horizontal, vertical, or diagonal) of accurately crossed out binomial names would yell out "Bingo!"
- Another way to extend this lesson would be to introduce the other "ranks" of taxonomic classification (kingdom, phylum, class, order, family). Each student could choose a few binomial names from his team's list or another team's list and research to which family, order class, phylum and kingdom those organisms belong.
- Teams' lists of binomial and common names can be assessed on accuracy and their use of the VT and the "Catalogue of Life" sites to validate their research.
- Students' understanding of binomial nomenclature could be easily assessed by giving the class a "binomial names quiz" to see if students can correctly match binomial names with common names and can identify which part of each binomial name indicates "genus" and which indicates "species."
Standard 7. Understands biological evolution and the diversity of life
Level III (Grades 6-8)
4. Knows evidence that supports the idea that there is unity among organisms despite the fact that some species look very different (e.g., similarity of internal structures in different organisms, similarity of chemical processes in different organisms, evidence of common ancestry)
Level IV (Grades 9-12)
5. Knows ways in which living things can be classified (e.g., taxonomic groups of plants, animals, and fungi; groups based on the details of organisms' internal and external features; groups based on functions served within an ecosystem such as producers, consumers, and decomposers)
6. Knows how natural selection and its evolutionary consequences provide a scientific explanation for the diversity and unity of past and present life forms on Earth (e.g., recurring patterns of relationship exist throughout the fossil record; molecular similarities exist among the diverse species of living organisms; the millions of different species living today appear to be related by descent from common ancestors)
7. Knows how organisms are classified into a hierarchy of groups and subgroups based on similarities that reflect their evolutionary relationships (e.g., shared derived characteristics inherited from a common ancestor; degree of kinship estimated from the similarity of DNA sequences)
Standard 4. Gathers and uses information for research purposes
Level IV (Grade: 9-12)
2. Uses a variety of print and electronic sources to gather information for research topics (e.g., news sources such as magazines, radio, television, newspapers; government publications; microfiche; telephone information services; databases; field studies; speeches; technical documents; periodicals; Internet)
Level III (Grades 6-8)
Standard 5. Uses the general skills and strategies of the reading process
2. Uses word origins and derivations to understand word meaning (e.g., Latin and Greek roots and affixes, meanings of foreign words frequently used in the English language, historical influences on English word meanings)
Level IV (Grades 9-12)
3. Uses a variety of strategies to extend reading vocabulary (e.g., uses analogies, idioms, similes, metaphors to infer the meaning of literal and figurative phrases; uses definition, restatement, example, comparison and contrast to verify word meanings; identifies shades of meaning; knows denotative and connotative meanings; knows vocabulary related to different content areas and current events; uses rhyming dictionaries, classification books, etymological dictionaries)
2. Extends general and specialized reading vocabulary (e.g., interprets the meaning of codes, symbols, abbreviations, and acronyms; uses Latin, Greek, Anglo-Saxon roots and affixes to infer meaning; understands subject-area terminology; understands word relationships, such as analogies or synonyms and antonyms; uses cognates; understands allusions to mythology and other literature; understands connotative and denotative meanings)
Standard 8. Uses listening and speaking strategies for different purposes
Level III (Grades 6-8)
1. Plays a variety of roles in group discussions (e.g., active listener, discussion leader, facilitator)
6. Makes oral presentations to the class (e.g., uses notes and outlines; uses organizational pattern that includes preview, introduction, body, transitions, conclusion; uses a clear point of view; uses evidence and arguments to support opinions; uses visual media)
Level IV (Grades 9-12)
5. Makes formal presentations to the class (e.g., includes definitions for clarity; supports main ideas using anecdotes, examples, statistics, analogies, and other evidence; uses visual aids or technology, such as transparencies, slides, electronic media; cites information sources)