Unit 2

Which structural feature is present in both prokaryotic and eukaryotic cells?

Ribosomes

Gram-positive cell envelopes are distinguished by having:

A thick peptidoglycan layer containg teichoic acids

What term describes a chain-like arrangement of spherical bacterial cells

Streptococci

How does prokaryotic DNA typically differ from eukaryotic DNA?

Prokaryotic DNA is circular and generally smaller with fewer genes.

what is the main function of bacterial fimbriae?

Attaching to surfaces and host epithelial cells to stay put.

Which bacterial shape is characterized by a helical or corkscrew-like form?

Spirilla or Spirochete

What is the main function of bacterial fimbriae?

Attaching to surfaces and host epithelial cells to stay put.

Which bacterial shape is characterized by a helical or corkscrew-like form?

Spirilla or Spirochete

What is the role of Gram’s iodine in the Gran staining procedure?

Mordant that stabilizes crystal violet into larger complexes.

Which bacterial appendage functions primarily as a rotating motor for motility?

Flagellum

Whic structural component is unique to bacterial cell walls and forms a rigid mesh layer?

Peptidoglycan

Which of the following structures is found in eukaryotic cells but is absent in prokaryotic cells?

Membrane enclosed nucleus

According to the Endosymbiont Theory, which eukaryotic organelles originated as independent prokaryotes that were enveloped by an ancestral eukaryotic host cell?

Mitchondria and Chloroplasts

Which structural component is found in the cell walls of fungi, distinguishing them from algae and plant cell walls?

Chitin

Which organelle acts as the “post office” of the cell by modifying proteins (adding lipids and sugars) and packaging them for transport to their final destination?

Golgi Apparatus

What is the primary functional difference between the Rough Endoplasmic Reticulum (RER) and the Smooth Endoplasmic Reticulum (SER)?

The RER is studded with ribosomes and houses proteins, while the SER processes non-protein commonents like lipids.

How do eukaryotic ribosome compare to prokaryotic ribosomes?

Eukaryotic cytoslic Horibosomes are 80s, while prokaryotic ribosomes are 70s

How are protozoans defined as a group?

Unicellular or colonial eukaryotic organims that lack true tissues.

Protozoans are frequently categorized based on their mechanisms of movement. Which structure is used by amoebas for movement and feeding?

Pseudopods

In the life cycle of many parastitic protozoans, what is the key difference between a trophozoite and a cyst?

A trophozoite is the active feeding and replicating stage, while a cyst is the protected dormant survival stage.

A patient is admitted to the hospital with a productive cough and trouble breathing. The patient recalls cleaning out an old shed with visible mouse droppings. A sputum sample is taken and fuzzy hair-like structures are visible under the microscope. Further staining reveals the organism is multicellular and contains a nucleus. What is the likely identity of this organsim?

A fungus

A memeber of the ciliates lives in the ocean and hunts for food. In order to find its food source, it must take sips of the environment to find chemical singals related to their food. This is an example of?

Pinocytosis

All bacterial cells posses a cell membrane, cytoplasm, double-stranded circular DNA, and ribososomes.

True

Which sequence correctly outlines the steps of bacterial binary fission?

Parent cell elongates and replictaes DNA → DNA segregates → septum forms → Cells spilts into two identical daughter cells

In the protozoan life cycle, the active, motile, feeding stage is called the ______, whereas the dormant, resistant survival stage is the ______.

Trophozoite; cyst

Passive diffusion differs from active transport across the prokaryotic cell membrane becuase passive diffusion:

Moves molecules down their concentration gradient without expending cellular energy (ATP).

Which of the following is the defining structural characteristic of all prokaryoitic cells?

Absence of a membrane-enclosed nucleus.

What occurs when a bacterial cell is placed in a hypertonic solution?

The cell loses water and undergoes plasmolysis.

During bacterial conjugation, plasmid DNA is transferred from a dnor bacterium to a recipient bacterium through which specialized appendage?

S*x pilus (F-pilus)

Pairs of rod-shaped bacterial cells is termed ______.

Diplobacilli

What is the Endosymbiont Theory?

The theory that eukaryotic cells evolved when ancient cells formed a symbiotic relationship with prokaryotic cells.