The lytic cycle is a virulent infection process where the bacteriophage hijacks the host's metabolic machinery to synthesize viral components. Once assembly is complete, the host cell undergoes lysis, releasing a large number of progeny virions into the surrounding environment to infect new host cells.
2162
What is the term for the loose, soluble macromolecular shield covering some bacteria?
The slime layer is a diffuse, unorganized, and easily removable layer of extracellular material that surrounds some bacterial cells. Unlike the capsule, which is rigid and well-organized, the slime layer is loose and soluble, providing protection and aiding in adherence to surfaces.
2163
To which taxonomic group does the genus Mucor belong?
The question asks for the classification of the genus Mucor. While Mucor is a member of the order Mucorales and the family Mucoraceae within the class Zygomycetes, the provided answer key identifies 'mucor' itself as the intended choice, which is technically redundant but reflects the source material.
2164
What term refers to dormant, thick-walled structures that are highly resistant to desiccation and environmental stress?
Cysts are specialized, dormant, thick-walled structures produced by certain bacteria to survive harsh environmental conditions such as nutrient deprivation or desiccation. While endospores are also resistant structures, the term 'cysts' is specifically used in many contexts to describe these protective, non-reproductive resting stages in various microbial groups.
2165
Which bacterial structure provides protection against phagocytosis?
The slime layer, often composed of polysaccharides, can help bacteria evade the host immune system by preventing phagocytosis. While capsules are also known for this function, the provided answer key identifies slime as the correct choice in this context. This may be due to specific terminology regarding extracellular polymeric substances.
2166
To which group of microorganisms does the genus Mycobacterium belong?
Mycobacterium is a genus of Actinobacteria, which are Gram-positive bacteria often characterized by their filamentous growth, similar to fungi. They are classified within the order Actinomycetales. This group is known for its high guanine and cytosine content in their DNA and includes many soil-dwelling species as well as significant human pathogens.
2167
Which term describes bacteria that possess a thin, flexible, and spiral-shaped morphology?
Spirochetes are characterized by their unique helical, flexible, and thin body structure. Unlike spirilla, which are rigid, spirochetes utilize axial filaments located between the cell wall and the outer sheath to achieve motility, allowing them to move in a corkscrew-like fashion through viscous environments.
2168
Which group of fungi is commonly referred to as the 'imperfect fungi'?
Deuteromycota, often called Fungi Imperfecti, is a group of fungi where a sexual reproductive stage has not been observed or is absent. They reproduce primarily through asexual spores called conidia. Modern classification often places these organisms within Ascomycota or Basidiomycota based on molecular data.
2169
To which taxonomic order does the genus Mucor belong?
The genus Mucor is the type genus for the order Mucorales. This order is a major group within the phylum Zygomycota (or Mucoromycota in modern classification), characterized by the production of coenocytic hyphae and the formation of zygospores during sexual reproduction.
2170
In the sarcina arrangement, how many planes of cell division occur?
Sarcina bacteria are characterized by cell division occurring in three perpendicular planes. This specific pattern of division results in the formation of cuboidal packets or clusters consisting of eight or more cells, which remain attached to each other after the division process is complete.
