JeffState Microbiology Ch #5

What are the three domains of life that evolved from the Last Common Ancestor (LCA)?

Bacteria, Archaea, and Eukarya.

How did endosymbiosis contribute to the development of eukaryotic cells?

Mitochondria and chloroplasts originated when bacterial or archaeal cells were engulfed by larger eukaryotic cells, forming a permanent symbiotic relationship.

What evidence supports the endosymbiotic theory?

Mitochondria and chloroplasts possess their own circular DNA, 70S ribosomes, and two-layer membranes.

Which eukaryotic microorganisms are always unicellular?

Protozoa.

Which eukaryotic microorganisms may be unicellular or multicellular?

Fungi and Algae.

Which eukaryotic microorganisms are always multicellular?

Helminths.

What is the function of the glycocalyx in eukaryotic cells?

Protection, adherence, and signal reception.

What are the main structural components of a nucleus?

Nuclear envelope, nucleolus, and chromatin.

What is the role of the rough endoplasmic reticulum (RER)?

Holds proteins for packaging and transport; studded with ribosomes.

What is the function of the smooth endoplasmic reticulum (SER)?

Synthesizes and stores nonprotein molecules such as lipids and steroids.

What is the function of the Golgi apparatus?

Modifies proteins by adding polysaccharides/lipids and packages them into vesicles.

What is the primary function of mitochondria?

Cellular powerhouses for ATP generation.

What distinguishes eukaryotic ribosomes from bacterial ribosomes?

Eukaryotic ribosomes are 80S, while bacterial/mitochondrial ribosomes are 70S.

What are the three main fibers of the cytoskeleton?

Actin filaments, intermediate filaments, and microtubules.

What is the structure and function of eukaryotic flagella?

10× thicker and more complex than bacterial flagella, covered by the cell membrane, and moves in a whipping motion.

What is the structure and function of cilia?

Shorter and more numerous than flagella, found in certain protozoa and animal cells, used for motility, feeding, and filtering.

What is the composition of eukaryotic cell walls?

Contain chitin or cellulose and differ chemically from bacterial cell walls.

What is the process of protein transport in eukaryotic cells?

Genetic code from nucleus → mRNA to RER → proteins synthesized → vesicles to Golgi → modification and packaging → secretion or delivery.

What are lysosomes and their function?

Contain digestive enzymes for intracellular digestion and protection.

What are vacuoles and their function?

Membrane-bound sacs for storage, digestion, or water regulation.

What is the significance of the nucleolus?

Site of rRNA synthesis within the nucleus.

What is the role of chloroplasts in eukaryotic cells?

Convert sunlight into chemical energy via photosynthesis.

What is the difference between tissues and organs?

Tissues are groups of similar cells working together, while organs are structures composed of multiple tissue types.

What is the typical cell wall characteristic of fungi?

Fungal cell walls contain chitin.

Which group of eukaryotic microorganisms usually lacks a cell wall?

Protozoa.

Do bacterial and archaeal cells have a true nucleus?

No

Do eukaryotic cells have a true nucleus?

Yes

What type of genetic material do bacterial cells have?

Single circular chromosome

What type of genetic material do eukaryotic cells have?

Multiple linear chromosomes

What type of genetic material do viruses have?

DNA or RNA

Do bacterial cells undergo mitosis or meiosis?

No

Do eukaryotic cells undergo mitosis or meiosis?

Yes

Do viruses undergo mitosis or meiosis?

No

What type of ribosomes do bacterial cells have?

70S ribosomes

What type of ribosomes do eukaryotic cells have?

80S ribosomes

Do viruses have ribosomes?

No

Do bacterial cells have mitochondria?

No

Do eukaryotic cells have mitochondria?

Yes

Do viruses have mitochondria?

No

What is the general size range of bacterial cells?

0.5 - 3 µm

What is the general size range of eukaryotic cells?

2 - 100 µm

What is the general size of viruses?

< 0.2 µm

What type of locomotion do bacterial cells have?

Bacterial type flagella

What type of locomotion do eukaryotic cells have?

Eukaryotic flagella (9+2 arrangement)

Do viruses have locomotion?

No

What is a characteristic of fungal cells?

All fungi are heterotrophic

What is mycelium?

A woven mass of hyphae that makes up the colony of a mold

What are the two types of fungal spores?

Asexual spores (Sporangiospores and Conidiospores) and sexual spores

What is a dimorphic fungus?

A fungus that can switch between yeast and hyphae forms depending on conditions

What is the primary mode of reproduction in fungi?

Spores

What are the two major groups of helminths?

Flatworms (Platyhelminthes) and Roundworms (Nematodes)

What is the life cycle of a typical helminth?

Fertilized Egg → Larval Stage → Adult Stage

What type of nutrition do protozoa exhibit?

Heterotrophic

What are the three means of locomotion exhibited by protozoa?

Pseudopods, Flagella, and Cilia