MicroBiology-240 Chapter 1 Study Questions

How long have single-celled organisms existed on Earth?

About 3.8 billion years.

What three types of cells are recognized in microbiology, and which contain a nucleus?

Eukaryotes (contain a nucleus), Prokaryotes, and Akaryotes (both lack a nucleus).

Helminths are

multicellular worms

What does it mean when we say microbes are "ubiquitous"?

Microbes are found everywhere and are essential to life.

How do microbes contribute to the Earth's atmosphere?

They produce atmospheric O₂, and also CO₂, NO, and CH₃ that help insulate Earth’s atmosphere.

What role do microbes play in the oceans?

They are the most abundant organisms in the oceans.

How do bacteria and fungi benefit plants?

They enhance nutrient uptake, improve soil structure, and protect against pathogens.

List five historical uses of microbes by humans.

Cheese production, treating wounds and lesions, mining precious metals, wastewater treatment, and antibiotic production.

What is biotechnology, and how is it applied?

Biotechnology is when humans manipulate microbes to create products in an industrial setting.

What is recombinant DNA technology used for?

To create new products and genetically modified organisms (GMOs).

What is bioremediation, and how do microbes contribute to it?

Bioremediation is the use of microbes to restore ecosystems and clean up toxic pollutants.

Are most microbes that associate with humans harmful or harmless?

The vast majority are harmless.

What is a pathogen?

A pathogen is a microorganism that causes disease.

What is an infectious disease?

A disease that is caused by a microorganism.

The science of organizing, classifying and naming living things is called

Taxonomy

How many different microbes are known to cause disease?

Over 2,000 different microbes.

What are emerging and re-emerging diseases? Give an example of each.

Emerging diseases are new, e.g., COVID-19 and HIV;
Re-emerging diseases were once common, declined, and are making a comeback, e.g., Tuberculosis.

What is the difference between eukaryotes and prokaryotes?

Eukaryotes have a nucleus; prokaryotes do not.

Which microorganisms are considered cellular, and which are acellular? (List all)

Cellular: Bacteria, Archaea, Fungi, Protozoa, Algae
→ Acellular: Viruses, Prions

What distinguishes bacteria from archaea?

Archaea are distinct from bacteria and often live in extreme environments. Their cell walls lack peptidoglycan.

Why aren’t viruses included in any of the three domains of life?

Because viruses are not cells.

What is binomial nomenclature, and how is a scientific name formatted?

It's a system where the scientific name combines genus and species; names are italicized in print and underlined in handwriting.

How do you properly abbreviate a scientific name?

Use the first letter of the genus (capitalized) and the full species name, e.g., E. coli.

List the 8 major taxonomic ranks from most general to most specific.

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

What domain includes organisms with peptidoglycan in their cell walls?

Domain Bacteria

Which domain includes organisms found in extreme environments?

Domain Archaea

Which domain includes fungi, protozoa, and helminths?

Domain Eukarya

Among eukaryotes, there are ______.

single-celled and multicellular organisms

Viruses are

• Acellular

• Not Living

• less complex than cells

Define cellular and acellular

• Cellular= Made up of cells

• Acellular= not made up of cells

Recombinant DNA technology involves the transfer of ______ from one organism to another.

genetic material

Which cell type is generally larger in size?

Eukaryotic cells