Text Rendering Activity

Transcription

1 Text Rendering Activity Name Period Date Directions: The following is a nonfiction article that was written to provide you with information on how living organisms are classified and named. As you read: highlight important information. highlight and place a question mark next to confusing or difficult text. draw a box around words or terms you don t know. write connections, questions, or I wonder statements in the right-hand column. Purpose: As you read, think about: the seven-layer system used to classify organisms. how different organisms may be related. how organisms have a two-part scientific name. why taxonomy is useful to scientists and biologists.

2 What s in an Organism s Name? (from Organisms Macro to Micro p. 8-11) Even if you didn t know much about biology, you probably could guess that lions and tigers are close relatives. You also could be pretty sure that bears are animals and that roses are plants. It s easy because these organisms are familiar to us and have such distinctive appearances. What if you had to find out whether mice, elephants, and bats were related? To answer this question, you would turn to taxonomy. Taxonomy is the science of classifying living things. Taxonomy is based on the principle that everything in our world is related in some way. It is a science that groups organisms according to their structures and functions. Taxonomy was introduced in the 18 th century by Carolus Linnaeus, a Swedish scientist. Linnaeus s interest in taxonomy started early. His father had a large garden, and he introduced his son to the science of plants. Linnaeus enjoyed studying plants, but even as a boy, he recognized that little information was available about how to classify plants. He saw a need for a universal classification system that would allow all scientists to communicate with one another about living things in a meaningful way. A Seven-Layer System Linnaeus developed rules for classifying plants and animals according to their structures. His work resulted in a seven-layer

3 system: kingdom, phylum, class, order, family, genus, and species. You can think of the system as an upside-down triangle. The top layer of the triangle is the kingdom category. Each kingdom contains the greatest number and diversity of organisms of the entire system. Because this layer is the largest, the organisms in it have fewer features in common than do organisms in the six other layers. For example, creatures as different as jellyfish and lions are both part of the Animal Kingdom. As you move down the triangle, fewer organisms are included in each category, but the organisms within each category have more features in common. I wonder what the upside-down triangle would with all the layers would look like. Look at Table 1.1 on p. 10. You will see that all of the organisms listed across the top of the table are in the same kingdom, phylum, and class. With the exception of humans, they are also in the same order. The god and grey wolf are in a different family than the four cats. And, of the four cats, only the tiger and the lion are in the same genus. The lion has the species name leo, which makes it unique from all the other animals in the chart. Using Linnaeus s system, ants and spiders are part of the animal kingdom. They are also both members of the phylum Arthropoda (ar-throp-oh-dah) because they have jointed legs. But each is in different class. Ants are in the class of animals with three-part bodies and six legs. This class is called Insecta. Spiders are in the class of eight-legged organisms with two-part bodies. This class is known as Arachnida (ah-rak-nî-dah).

4 Adding New Kingdoms Linnaeus grouped all organisms into two main kingdoms Plants and Animals. Until the second half of the 20 th century, most biologists used his system. Then they added a third kingdom, the Protists, because microorganisms did not all clearly fit into the Animal of Plant kingdoms. As scientists discovered more and more information about organisms, they added two more kingdoms Fungi and Monerans. One Organism, Two Names Linnaeus also developed a system for naming organisms, under which a two-part scientific name is assigned to every organism. An organism is named on the basis of its genus and species. The species name is usually an adjective, and the genus name is usually a noun. The first letter of the genus name is always capitalized. When the scientific name is typed, it is always in italics. When written by hand, it is always underlined. Some organisms are named after one of their prominent features. The scientific name for the red maple, for example, is Acer rubrum. Acer means maple, and rubrum means red. Some are named after the location in which they are found. A species of fly discovered in Humbug Creek, California, was named Oligodranes humbug. Others are named after the scientist who discovered them. There are other sources of names, too. There is a spider, Draculoides bramstokeri, named after the novel, Dracula, by Bram Stoker. Perhaps the grandfather of all names belongs to a tiny insect. Its scientific name is

5 Myzocallis kahawaluokalani. This Hawaiian name supposedly means, You fish on your side of the lagoon and I ll fish on the other, and no one will fish in the middle. Linnaeus s groundbreaking work of the 18 th century remains the basis of the system we use today. Taxonomy now helps scientists to classify more than 10 million species of organisms on Earth and new kinds are discovered every year. Taxonomy is likely to continue to evolve as scientists debate the most appropriate classification system and the need to change that system to reflect new information and discovery.