Session #25

Front

What is the function of the complement system in the immune response?

Back

The complement system enhances the ability of antibodies and phagocytic cells to clear pathogens from an organism. It promotes inflammation, opsonization, and the formation of the membrane attack complex.

Front

What is the role of the sigma factor in bacterial transcription?

Back

Sigma factors are proteins that bind to RNA polymerase and direct it to specific promoters, initiating transcription. They are crucial for the regulation of gene expression in bacteria.

Front

Define amensalism in ecological terms.

Back

Amensalism is a type of interaction between two species where one is harmed while the other is unaffected. An example is the production of penicillin by Penicillium chrysogenum, which inhibits bacterial growth.

Front

What is the significance of the sigma factor spo0A?

Back

Spo0A is known as the 'Master regulator' in Bacillus subtilis, controlling the initiation of sporulation and other developmental processes.

Front

What does the appearance of the spore core indicate during germination?

Back

The core of the spore appears black near the end of germination, indicating that metabolic activity is resuming as the spore transitions to a vegetative state.

Front

What is the role of σG in bacterial sporulation?

Back

σG is a sigma factor that activates the expression of genes necessary for the later stages of sporulation in Bacillus subtilis.

Front

Explain the term 'phagocyte recruitment' in the immune system.

Back

Phagocyte recruitment refers to the process by which immune cells, such as macrophages and neutrophils, are attracted to sites of infection or inflammation to engulf and destroy pathogens.

Front

What is the membrane attack complex (MAC)?

Back

The membrane attack complex is a structure formed by the complement system that creates pores in the membranes of target cells, leading to cell lysis and death.

Front

Differentiate between commensalism and mutualism.

Back

Commensalism is a relationship where one species benefits while the other is neither helped nor harmed, whereas mutualism is a relationship where both species benefit from the interaction.

Front

What is the function of inflammatory agents in the immune response?

Back

Inflammatory agents, such as cytokines and chemokines, are signaling molecules that promote inflammation, recruit immune cells, and enhance the immune response to pathogens.