Week 1: Classification Flashcards
Age of Earth? Age of Microorganisms?
Earth 4.5 billion years, microorganisms 3.8 billion years.
On what basis are organisms classified by?
Evolutionary ancestry
List the eight levels of groupings in a classification scheme, beginning with domains.
Dear King Philip Came Over For Good Soup….Domain-Kingdom-Phylum-Class-Order-Family-Genus-Species
What are the three domains into which all living things are classified? Which of these groups are prokaryotic? Which of these groups contain microorganisms?
Bacteria, Archaea, and Eukarya. Bacteria and Archaea are prokaryotic. All 3 contain microorganisms.
What characteristics are shared by bacteria and archaea?
Prokaryotes, smaller than eukaryotes, superficially resemble each other, unicellular, asexual reproduction.
On what basis was it determined that bacteria and archaea should be classified into different domains?
Based on differences in ribosomal RNA sequences.
What characteristics differ between bacteria and archaea?
Bacteria have peptidoglycan cell walls while archaea do not. Archaea are also extremophiles.
Do fungi represent an evolutionary grouping?
Yes
List the general features common to all fungi.
Eukaryotic, rigid cell walls, chemoheterotrophs, both unicellular and multicellular membranes, mostly sprobes some pathogens.
Chemoheterotrophs
Obtain carbon and energy from other organisms.
Are fungi unicellular or multicellular?
Some are unicellular (yeast), some multicellular (mold/mushrooms), and some are dimorphic (exist in both forms).
Dimorphic
Organism that has can switch between unicellular and multicellular during it’s life cycle.
How do fungi get their energy?
They obtain carbon and energy from other organisms (chemoheterotrophs). Normally dead things, some can obtain nutrients from live things (saprobes vs. pathogens).
Saprobes vs. Pathogens
Food from dead things vs. live things
How are fungi important in the environment and humans?
Play a role in food production, antibiotics, and food spoilage. Also major decomposes in the environment.
Two diseases caused by fungi?
Athletes foot and oral/vaginal yest infections.
Describe the relationship present in mycorrhizae, including the benefits gained by each partner.
Beneficial association between fungi and plant roots. Fungi get carbohydrates and plants get increased ability to absorb water and minerals.
Describe the relationship present in lichen, including the benefits gained by each partner.
Beneficial association between fungi and a photosynthetic partner. Fungi provides nutrients, water, and protection. Algae or cyanobacterium provides carbohydrates.
Why are viruses considered non-living?
Because they are not composed of cells and are obligate intracellular parasites.
Proins
-Only protein no genetic material, normally occurring protein
-folded into an aberrant shape
-causes degeneration of brain function resulting in mad cow disease and chronic wasting disease.
Viroids
Small circular RNA molecules, infectious and pathogenic in plants.
Viruses
DNA or RNA surrounded by capsid, infectious agent.
List the three types of non-living infectious agents?
Viruses, Viroids, Proins
What characteristics do non-living groups share with each other?
Not composed of cells and are obligate intracellular parasites.
How are fungi and bacteria alike? How are they different?
- Fungi are eukaryotes while bacteria are prokaryotes.
- Bacteria are single celled whereas most fungi are multicellular except for yeast.
- The compositions within their cell walls are different.
- Fungi are heterotrophs while Bacteria can be autotrophs or heterotrophs.
- Bacteria have 3 distinct shapes while fungi have various shapes.
- Bacteria reproduce sexually via binary whereas fungi are capable of reproducing both sexually or asexually.
Do algae represent an evolutionary grouping?
No
List the general features common to all algae.
Eukaryotes that perform oxygenic photosynthesis in chloroplasts. Unicellular, colonial, or multicellular. Similar repro structure than plants. Mostly aquatic and produces most of the worlds oxygen.
How are algae important to humans and the environment?
Source of food for aquatic and marine animals. Produces the majority of the worlds oxygen.
How are algae and bacteria alike? How are they different?
Algae are photosynthetic eukaryotes, bacteria are not. Bacteria are unicellular and algae can exist as uni, multi and colonial organisms. They both represent an evolutionary group and have rigid cell walls.
How are algae similar to fungi? How are they different?
-They are both eukaryotes
-can exist as uni or multicellular organisms,
-rigid cell walls and both diverse groups of eukaryotes.
-They differ in their composition
-purposes they serve to their environment, algae produce O2 and fungi are decomposers.
Do protozoa represent an evolutionary grouping?
No
List the general features common to all protozoa.
Diverse group of eukaryotes defined by 3 characteristics (eukaryotic, unicellular, lack a cell wall). Most heterotrophs but some photosynthetic, most motile via cilia, flagella, or pseudopodia, most aquatic, some parasitic, cause disease in humans.
Are protozoa unicellular or multicellular?
Unicellular
How do most protozoa get their energy?
Hetertrophs
How do protozoa move?
Cillia, flangella, or pseudopodia.
List at least two diseases caused by protozoa, including the causative agent of each.
Malaria caused by the protozoa of the genesis plasmodium. Giardiasis caused by giardia duodenalis “giardia”.
How are protozoans and bacteria alike? How are they different?
They are both unicellular. Protozoans are eukaroytic while bacteria are prokaryotic. Protozoans have no cell wall and bacteria do. Bacteria produce a sexually through binary fission and protozoans do not.
How are protozoans and fungi alike? How are they different?
-Both are eukaryotic.
-Fungi are dimorphic while protozoans are unicellular.
-Fungi have rigid cell walls while protozoans do not have a cell wall.
-Fungi are composed of polysaccharide chitin.
ow are protozoans and algae alike? How are they different?
Protozoans are uni cellular and algae can exist in this form. Both eukaryotes. Algae have rigid cell walls while protozoans do not have cell walls.
Are helminths microscopic? Explain.
No, macroscopic but are normally microscopic in early lifecycle stages.
Helminths
Parasitic worms
Why are helminths studied in a microbiology course?
importance as disease- causing organisms.
Three groups of helminths?
Round worm, tapeworm, flukes
Are helminthes unicellular or multicellular?
Multicellular
To which eukaryotic kingdom do helminths belong?
Kindgom Animalia
How are helminths and bacteria alike? How are they different?
Both can be pathogenic
Bacteria are Prokaryotes and Helminths are Eukaryotes
Bacteria are micro and helminths are macro
Bacteria have cell walls and helminths do not
Bacteria are unicellular and helminths are multi
How are helminths and fungi alike? How are they different?
Both are Eukaryotic
Both can both exist as multi cellular organisms
Both can be pathogenic
Fungi have rigid cell walls helminths lack them
Fungi are micro and helminths are macro
Fungi are decomposers and helminths are parasites
How are helminths and algae alike? How are they different?
Both can exist as multicellular organisms
Both are eukaryotes
Helminths lack cell walls and algae have them
Helminths are macroscopic algae are micro
Helminths are parasites algae are photosynthetic
How are helminths and protozoa alike? How are they different?
Both are eukaroytic
Both lack cell walls
Helminths are multi and protozoa are uni
Helminths are macro and protozoa are micro
Which of the following is NOT a domain into which living organisms are classified?
Question options:
A) Algae
B) all of these groups ARE domains into which living organisms are classified
C) Archaea
D) Bacteria
E) Eukarya
A) Alage
Which of the following is NOT a feature of all protozoa?
Question options:
A) unicellular
B) ALL of these are features of protozoa
C) possessing internal membranes
D) eukaryotic
E) lacking a cell wall
C) Possessing internal membranes