MICROBESChapter 11

Standard Course of Study 6.03: Compare the life functions

of protists. 7.01: Compare and contrast

microbes. Students will be able to explain

the differences between protists, bacteria, and viruses.

VOCABULARY: virus, bacteria, protist, euglena, amoeba, paramecium, volvox

What is a microbe? A microbe is an organism

that can only be seen with the help of a microscope.

Microbes include: Viruses Bacteria Protists Fungi

ProtistsProtists are eukaryotes because they have a nucleus, but cannot be classified as plants, animals, or fungi.

Single- or multi-celledMay move with cilia, flagella, or pseudopods.

Size: 10 micrometers to 100 meters

Three Types of Protists1. Plant-like: get energy from sun

2. Animal-like: move through the environment & eat other organisms

3. Fungus-like: absorb nutrients from the environment

Examples of ProtistsEuglena: plant-like, but can be autotroph or heterotroph

Volvox: plant-like, lives in colonies

Amoeba: animal-like, moves with pseudopods

Paramecium: animal-like, moves with cilia

Diagram of a Protist•Nucleus•Nucleolus•Vacuoles•Mitochondria•Chloroplasts

Which statement best explains the movement of Euglena?A) It expands and contracts its muscles.

B) It sways its tentacles.C) It floats in its environment.

D) It swings its flagella.

How do Amoebae move? A) They move by using cilia.B) They move by using pseudopods.

C) They move by using a flagellum.

D) The cells move by swimming together.

What is one way Amoebae are different from Paramecia? A) Amoebae move in a way

different from that of Paramecia. B) Amoebae are decomposers,

but Paramecia are producers. C) Amoebae produce their own

food, but Paramecia do not. D) Amoebae have cilia, but Paramecia do not.

Bacteria Single-celled Bacteria are prokaryotes. Their

genetic material is not found in a nucleus.

Size: 1-2 micrometers Three main shapes: spherical,

rodlike, or spiral.

Examples of Bacteria Cyanobacteria E. coli Lyme disease Pneumonia Syphilis Strep throat Anthrax Tetanus

Bacteria Diagram

•Genetic material•Ribosomes•Cell wall•Cell membrane•Cytoplasm•Flagella

Viruses A virus is a tiny, non-living

particle that enters and then reproduces inside of a living cell.

A virus may have DNA or RNA Many shapes of viruses. Size: 10-1,000 nanometers

Examples of VirusesEbolaHIV Influenza (flu)Chicken poxHepatitisRabiesPolio

Virus StructureViruses have two parts: Genetic material (DNA or RNA)

Protein coat

Virus Reproduction

Which microorganisms are generally classified as nonliving?

A) bacteriaB) fungiC) protistsD) viruses

Which would be the most complex to study due to its changing structure?

A) polio virusB) influenza virusC) leprosy bacteriaD) pneumonia bacteria

Which list of microbes is arranged in order of increasing size? A) virus, protist, bacteriaB) virus, bacteria, protistC) bacteria, virus, protistD) bacteria, protist, virus

Which is a microbe that contains genetic material and protein and is unable to reproduce outside a living cell? A) virus

B) fungusC) protistD) bacteria

Which structure is found only in eukaryotes? A) nucleusB) ribosomeC) cell wallD) cell membrane

Which best describes the main structural difference between viruses and bacteria? A) Bacteria have DNA only; viruses

have a cell wall and DNA. B) Bacteria have a cell membrane

and DNA; viruses have DNA only. C) Bacteria have a protein coat and

DNA; viruses have a cell membrane and DNA.

D) Bacteria have a cell wall, DNA, cytoplasm, and ribsomes; viruses consist of a protein coat and DNA.

Influenza is caused by which microbe?

A) bacteriumB) fungusC) parasiteD) virus

Why are viruses not considered living organisms? A) They cannot grow.B) They do not require oxygen.C) They cannot reproduce on their own.

D) They do not have a semi-permeable membrane.

Which statement best contrasts a bacterium and a virus? A) A bacterium can reproduce,

whereas a virus will not reproduce. B) A bacterium does not live on living

things, whereas a virus does. C) A bacterium is a one-celled living

organism, whereas a virus is a nonliving organism.

D) A bacterium is a nonliving organism, whereas a virus is a one-celled living organism.

How does the size of bacteria compare to the size of viruses? A) Bacteria are larger than viruses.

B) Bacteria are smaller than viruses.

C) They are both relatively the same size.

D) The size depends on the specific virus or bacteria.