Classifying Life Lesson 2

Think about your kitchen and how it’s organized… List some reasons we organize our kitchens? Saves space Makes things easier to find Makes preparing food easier Are kitchen items put in groups because of their similarities or differences? similarities

Grouping living things What do you think might be the best way to put living things into groups? By their similarities What are some groups of living things? Animals, plants, fungi, protists, bacteria

How do scientists organize all living things? Scientists classify organisms according to how closely they are related and to their similarities, such as physical characteristics, how an organisms obtains food or reproduces, where an organism lives, and genetic information.

Activity Time!!! Let’s practice classifying certain items in our classroom…OUR SHOES! Each person in the group will remove one shoe. The groups shoes will be placed in one pile. Groups will have 3 minutes to group together, or classify, shoes by their similarities. Be prepared to explain to the class what characteristics your group used to classify the shoes.

How are organisms classified? There are millions of different organisms on Earth. Scientists organize these organisms by sorting, or classifying, them into groups according to shared characteristics.

Classification Classification has been called the science of finding patterns. Classifying helps scientists identify, study, group, and name organisms.

Classification System One classification systems used today divides all organisms into 5 major groups called kingdoms. The broadest group an organism is classified into is a kingdom. Scientists classify organisms into kingdoms by carefully comparing their cells, tissues, organs, and organ systems.

Kingdoms Kingdoms are very broad groups. Do you think horses and spiders have much in common? They don’t, but they are both included in the animal kingdom. Smaller groups are needed to completely classify an organism. 6 subgroups are used to classify within kingdoms.

Subgroups Subgroups are: Phylum Class Order Family Genus Species

Species The narrowest group an organism can be classified into is a species. A species contains only organisms that are very closely related. A horse and a zebra share many traits, but they are not similar enough to be the same species. A horse and a pony are so similar that they are the same species.

“Read a Chart” Is a horse more closely related to a spider or a dog? A horse is more closely related to a dog because they are both in the same class. Spiders share only the same kingdom with the horse and dog.

Why are smaller groups necessary for classification? A large group, such as a kingdom, contains too many organisms. Smaller groups or similar organisms are easier to study.

What makes organisms in the animal kingdom different from organisms in the other kingdom? All animals are multicellular. Plants and animals are the only kingdoms that include only multicellular organisms. Animals do not make their own food like plants. They consume other organisms to get energy. Animal cells do not have cell walls. Many animals are capable of moving from place to place.

Animal kingdom One of the largest kingdoms! Features 9 phyla that belong to two major groups: Vertebrate Invertebrate

Vertebrates A vertebrate is an animal with a backbone. Within the vertebrate group, there are 7 classes: Amphibians Reptiles Birds Mammals And 3 classes of fish

Invertebrates An invertebrate is an animal without a backbone. The phyla includes: Mollusks – clams and snails Echinoderms – sea stars, sea cucumbers, and sea urchins Arthropods – Largest invertebrate phylum. More arthropod species than there are species in all the other animal phyla. Includes insects, spiders, crabs, and lobsters.

Review What is the broadest classification group? Kingdom What is the narrowest group? Species

“Critical Thinking” Why do scientists use only the genus and species names to identify an organism and not all of the classification groups? One possible reason would be that using all the names would be awkward.

Animal Kingdom What are some examples of organisms that are animals? Fish, snake, cow, sponge, dragonfly, and jellyfish. How are these animals alike? They move, eat food, and are made of many cells. How are these animals different? One main difference is some have backbones and some do not (vertebrates and invertebrates).

How are animals different from plants? Plants make their own food, stay in one place, and have different internal structures.

Which animal phylum contains the most species? The arthropods have the most species Which contains the fewest species? The echinoderms have the fewest species.

Review How would you classify a dog and a butterfly? Dogs are vertebrates. They have backbones. Butterflies are invertebrates. They do not have backbones.

Critical Thinking An organism looks like an animal, but it does not move. How could you determine if it is an animal? Look at the structure of its cells under a microscope. You can conclude the organism is an animal if it is made of animal cells.

Plant Kingdom The plant kingdom includes about 350,000 plant species. All plants are multicellular and make their own food. Plants are organized into 2 major groups: Vascular – contains tubes and vessels Nonvascular – do not have vascular tissue

Vascular Plants Vascular plants have a system of vessels that run up and down the body of the plant. Vascular tissue carries water and nutrients up form the plants roots to its leaves. It also move sugars made in the leaves to other parts of the plant.

Nonvascular Plants Nonvascular plants tend to be much smaller than vascular plants. They remain small and close to the ground where they soak up water. Examples: Mosses Hornworts Liverworts

Fungus Kingdom Fungi organisms include: Mushrooms Yeast Mold Although most fungi are multicellular, yeast are unicellular fungi. Fungi are different from plants. They must get energy by breaking down dead or decaying plants and animals. They do not make their own food.

Use of fungi Many fungi are used by humans. Yeast is used to make bread rise. Mold and yeast are also used to make some foods, such as cheese. Some fungi are used to make medicine. Fungi can even grow on the human body!

What cell part is in the cells of plants and fungi, but not animals? A cell wall

Which plant part is used to classify plants into two main groups? The presence or absence of vessels or tubes.

How are plants an fungi alike and how are they different? Both plants and fungi have cell walls, do not move from place to place, and do not have true sense organs. Plants differ from fungi because they can make their own food. Fungi must obtain food from other organisms.

What would happen to a forest without fungi? Dead organisms would be piled up because they were not broken down. The nutrients from once- living material would not be available to other organisms.

Bacteria and Protists The simplest unicellular organisms have no nucleus. They are divided into 2 kingdoms: Bacteria Archaea They do not have a nucleus. They do not have other organelles, such as mitochondria. Organisms in these kingdoms are found almost everywhere – your toothbrush, food, your skin, and inside your body! Some bacteria cause diseases and infections (strep throat), but many produce no harmful effects.

Bacteria and Archaea Some bacteria and archaea are useful and helpful to other organisms. Cows cannot digest the grass they eat without the help of archaea. The archaea breaks down the grass that the cow has stored in its stomach so that it can be digested. We even need bacteria for digestion. Bacteria is in your intestines and help break down food. They also produce vitamin K your body needs.

Protists The protist kingdom contains unicellular and multicellular organisms. These can either make their own food or eat other organisms. Protists are larger than bacteria, but are mostly microscopic. The cells of protists have a central nucleus and other membrane-bound organelles. Protists have simple body structures and lack specialized tissues. Protists include: algae, amoebas, and slime molds.

Bacteria and Protists Bacteria are unicellular. Protists can be either unicellular or multicellular. What structures are missing in bacteria cells? A nucleus and organelles How are bacteria different from archaea? Bacteria include germs and can be harmful. They are everywhere. Archaea can be helpful and mostly live in harsh environments.

How are protists different from bacteria? Protists can make their own food or eat other organisms. They are larger than bacteria and some, but not all, are microscopic. The cells of protists also have a nucleus and other membrane-bound organelles.

Three main kinds of protists Plant-like Animal-like Fungus-like

Viruses Viruses cannot be classified in any of the 6 kingdoms because they do not carry out all of the basic life process. They are very small. They are smaller than bacterial cells. Some viruses are not harmful, but some enter the body of an organism and cause it to get sick. The common cold, chicken pox, polio, and HIV-AIDS are all caused by a virus. Once inside the body, a virus attaches itself to a cell and takes control of the cell’s activities. The cell gets filled with the virus particles and bursts open releasing the virus to invade other cells causing infection or disease.