Classifying OrganismsLesson 1:

How Do Scientists Classify Organisms?

5th Grade ScienceMr. Hughes

Life Science Big Idea

• Students will understand how scientists classify living things into six kingdoms based on internal and external structures.

Life Science Concept Map

Scientists classify organisms accordingto how closely they

are related.

All organisms can beclassified into one of

six kingdoms: archaebacteria, eubacteria

protists, fungi, plants, and

animals.

All living things are made of cells. Multicellularorganisms have many

types of cells.

Kingdoms of Living Things

• Biologists use a scientific system that organizes living things into groups.

• Scientists use 6 kingdoms: archaebacteria, eubacteria, protists, fungi, plants, & animals.

• Organisms are classified according to internal and external characteristics.

• Scientists use dichotomous keys to help identify organisms.

Classifying Most Living Things

Single-celled?

NOYES

Makes its own food?

Nucleus incell?

NO YESYES NO

Eats food?NO

YES

Fungi Animal

Plants

Protists Bacteria

Bacteria• Bacteria are among the smallest of organisms and are

the most numerous.

• Bacteria can only be seen with a microscope.

• Bacteria are single-celled and do not have a nucleus.

• Bacteria are divided into 2 kingdoms: archaebacteria and eubacteria.

-Cocci: round shape; join together to form chains

-Bacilli: rod-shaped; found in soil and water

-Spirochetes: look like worms; wriggle when seen

under a microscope

• Archaebacteria are the oldest known

organisms.

Protists• Most protists are single-celled; all protist

cells have a nucleus.

• Some protists share characteristics with fungi, plants, or animals.

• Animal-like protists are call protozoa:

-amoebas: uses false foot to move

-can’t make own food, so take from surroundings

Protists• Plant-like protists use energy from sun to create

own food-algae: adds oxygen to air

http://simply-science-nbep.blogspot.com/2011/06/algae-vs-plants.html - to read how algae and plants differ.

• Fungi-like protists have harmful effects on plants and animals.-slime mold: ooze slowly over dead trees and piles of fallen leaves.

• Paramecium moves slowly using tiny, hair-like structures called cilia that cover most of its body-cilia work like oars to move paramecium

forward and backwards

Fungi• Fungi can be single-celled or multicellular

organisms; all fungal cells have a nucleus.

• Fungi cell walls are made of the same substance that forms insect shells.

• Fungi absorb nutrients from their environment by decomposing other organisms.

• Fungi grow fast and reproduce through spores.

• Mushrooms are examples of fungi.

Pictures of Protists

Slime Mold - Protist

Algae- Protist

Amoeba- Protist

Multicellular- ProtistSeaweed

Mushroom Life Cycle

cap

stalk

spores

mycelium

Mushroom Life Cycle(continued)

1. A mushroom with a stalk and cap is the above-ground part of certain fungi species.

2. Spores are released from the mushroom cap.

3. Spores grow on a surface and form the mycelium.

4. The mycelium produces mature mushrooms.