chap456,161718 MICROEXAM STUDY

What are symbiotic relationships?

Interactions between organisms of different species, where microbes tend to live in communities with other microbes.

Define mutualism.

An interaction where both organisms benefit.

Define amensalism.

An interaction where one organism is harmed and the other is unaffected.

Define commensalism.

An interaction where one organism benefits and the other is unaffected.

Define neutralism.

An interaction where both organisms are unaffected.

Define parasitism.

An interaction where one organism benefits and the other is harmed.

What is the microbiome?

The collection of microbes and their genetic material that inhabit a specific organism or environment.

What characterizes Proteobacteria?

Gram-negative bacteria, subdivided into 5 groups, some from the microbiome and some are pathogens.

Give an example of a pathogenic Neisseria species.

Neisseria spp. causes gonorrhea and meningitis.

What distinguishes non-proteobacteria?

Gram-negative bacteria that are very different from the Proteobacteria group.

What are Gram-positive Bacteria characterized by?

They are classified by GC% content and are Gram-positive.

What defines deeply branching bacteria?

Evolutionary distinct from most other bacteria, exhibiting a wide variety of environmental tolerances.

What are unicellular parasites?

Also known as protists, these are single-celled organisms with specialized structures.

Give an example of a unicellular parasite that uses flagella for locomotion.

Euglena uses flagella for locomotion.

What are parasitic helminths?

Multi-cellular worms that are parasitic and most lay eggs or larvae.

What do fungi have in common?

They are a diverse group with cell walls that contain chitin and can be unicellular or multi-cellular.

What characterizes algae?

Photosynthetic protists that can be unicellular or multi-cellular.

What defines lichens?

A combination of algae and fungus in symbiosis.

What are the main characteristics of viruses?

Simple structures composed of genetic material covered in protein, relying on other organisms to complete their lifecycle.

What is host range?

The specific organisms a virus can infect; typically resolved to a specific cell type.

Define vector.

An organism that can harbor a virus and transmit it to its host, usually without negative effects.

What is a bacteriophage?

Viruses that are specific to bacteria; they 'eat' bacteria.

What is the common structure of a bacteriophage?

Most have a 'lunar lander' appearance with a genome encased by a protein capsid, tail fibers, and a sheath.

What is the difference between naked and enveloped viruses?

Enveloped viruses have an outer layer from their host's cell membrane; naked viruses do not require this outer layer to infect.

How are viruses typically classified?

Based on whether they are enveloped or naked and the type of genome (DNA or RNA, single-stranded or double-stranded, positive or negative).

What life cycles do virulent and temperate viruses exhibit?

Virulent viruses undergo only the Lytic cycle; temperate viruses can undergo both the Lytic and Lysogenic cycles.