What s In a Name? (Lexile 840L)

Size: px

Start display at page:

Download "What s In a Name? (Lexile 840L)"

Barrie Rich
6 years ago
Views:

6.12: lassification of Organisms What s In a Name? (Lexile 840L) 1 Shakespeare famously wrote in Romeo and Juliet, What s in a name? That which we call a rose by any other name would smell as sweet.

1 6.12: lassification of Organisms What s In a Name? (Lexile 840L) 1 Shakespeare famously wrote in Romeo and Juliet, What s in a name? That which we call a rose by any other name would smell as sweet. These words are meant to say that it doesn t matter what we call something. It may not matter to fiction writers what things are called, but it is very important to scientists. Scientists need a way to organize and classify groups of life forms. How scientists do that has changed over time, as we have learned more and more about the world around us. 2. s science discovers more about the characteristics of organisms, we have gotten better at classifying them. The most basic level of classification is prokaryote and eukaryote. Prokaryotes are those organisms that don t have a nucleus or other cell structures which are surrounded by membranes. They are species of bacteria and archae. Eukaryotes are those organisms that we can often readily identify by sight. Each of their cells has a nucleus and complex parts enclosed within membranes. They are animals, flowers, mushrooms, and protists. 3. domain is the largest rank of organism. There are three domains: Eukarya, acteria, and rchaea. Eukarya is the domain composed of eukaryotes: organisms that have a cell nucleus and a membrane that encloses a complex structure. Most of the organisms we commonly think of as animals fall within this domain. It includes all plants, fungi, and protists. acteria is the domain composed of bacteria. These prokaryotes include the oldest fossils on Earth. Though some bacteria cause disease, others can cure illness. rchaea is the domain composed of archae. These prokaryotes often reside in extreme places like the boiling water of a hot spring, or the oxygen-deprived ocean floor. 4. Every living being on the planet falls into one of these three domains. ll eukaryotes are a part of the Eukarya domain. ll bacteria are a part of the acteria domain, and all of archaea fall into the rchaea domain. 1

2 6.12: lassification of Organisms 5. The next smallest classification group is Kingdom. The eukaryotic Kingdoms are: nimalia, Fungi, Plantae, and Protista. The prokaryotic Kingdoms are Eubacteria and rchaea. Organisms are classified at this level based on the complexity of their cell make up and how they obtain nutrients and reproduce. 6. Some organisms have only one cell and are called unicellular. These organisms include bacteria, protists, archae, and some fungi. ecause they only have one cell, these organisms are usually tiny. However, some are large enough to be seen with the naked eye. These organisms must carry out all life processes within that one cell. In contrast, multicellular organisms have more than one cell. In multicellular organisms, cells serve specialized purposes and depend on each other to make sure the life processes of the organism succeed. 7. There are two ways an organism can get nutrients. utotrophs make their own, while heterotrophs consume other organisms to get what they need to survive. Most bacteria and archae are autotrophs. Most plants are photoautotrophic. They use light from the Sun to manufacture the food they need to survive. People are heterotrophs. We can walk around all day with our arms outstretched to the Sun and still need to consume other organisms to get the nutrients we need to survive. 8. There are two types of reproduction. In asexual reproduction, the offspring come from a single parent and only carry the genes of that parent. There are many different ways for an organism to reproduce asexually. They can even simply divide into two daughter organisms in a process called binary fission. Many unicellular organisms reproduce asexually. In sexual reproduction, a new organism is created by the joining of two different sets of genetic material. This happens with most multicellular organisms. 9. Naming and classifying organisms is a tricky process that must incorporate new discoveries and information. Knowing the basics can help you think like a scientist when you read about scientific discoveries. 2

3 6.12: lassification of Organisms 1 Why are humans called heterotrophs? Humans eat other organisms to get the nutrients they need to survive. Humans have a complex cell structure. Humans make offspring by joining two sets of genetic material. Humans have a nucleus and a cell membrane. 2 unicellular protist is part of which omain? rchaea acteria Eukarya Not enough information to determine 3 ased on the information in this passage, which of the following is a reasonable conclusion? Scientists will never change the classification system again. Scientists know everything there is to know about all organisms. Scientists have never changed the classification system. New scientific discoveries could change the current classification system. 3

4 6.12: lassification of Organisms 4 What is the most likely meaning of the root word photo in the word photoautotroph in Paragraph 7? Picture Light Nutrients Synthesis 5 Which of the following is the best summary of the story? Eukaryotes and prokaryotes are different. One has a nucleus with a cell membrane and the other does not. Humans are eukaryotes. There are many ways to classify organisms. They can be either bacteria or archaea. There are three omains of life. ll living creatures are a part of the Eukaryotic, acteria or rchaea omain. There are six Kingdoms, and organisms are grouped into Kingdoms based on the complexity of their cell structure, how they reproduce, and how they obtain nutrients. Organisms are everywhere. Some have a complex cell structure and some are unicellular. Some organisms thrive in extreme places. They are called archaea and can even live in hot springs and on ocean floors. 4

5 6.12: lassification of Organisms 1 rchaea acteria 2 nimalia Plantae 3 rchaea 4 U M M U U U M U M = unicellular = multicellular 6 Examine the incomplete graphic organizer pictured above. Which label belongs in box 3? Fungi Protista Eubacteria Eukarya 5

Reading Science! Name: Date: What s In A Name? Lexile 870L

Reading Science! Name: Date: What s In A Name? Lexile 870L 6.12: lassification of Organisms Name: ate: 1 2 3 What s In Name? Lexile 870L Shakespeare famously wrote in Romeo and Juliet, What s in a name? That which we call a rose by any other name would smell as