T-cell activation requires antigen being displayed in the context of an APC and interaction between co-stimulatory molecules on the APC and the T cell. In addition to these two signals, T cell activity is often influenced by cytokines. Which of the following is an example of how cytokines can influence T-cell activity in the presence of MHC presentation and costimulatory ligand interaction

A. Antigen-specific TCR binding to MHC peptide
B. Expression of CD4+ or CD8+
C. Interaction with CD80, CD86, or ICOS-L
D. Both A and B
E. Both A and C

What are chlorofluorocarbons made of

Study this image. which statements best describe the rock shown? check all that apply. the grains of this rock are jagged. this rock has several coarse grains. the grains in this rock are very large. this rock has a non-banded pattern. the color of this rock is determined by its texture.

With the description of the different cell walls, membranes, and associated proteins set in the students' minds, you now need to introduce them to the idea that the cell wall can also act as a foundation to build things upon. bacterial appendages require a strong foundation that will offer the support needed to move and function in a dynamic world. for example, flagella are long, whiplike protein structures that are used by many gram-positive and gram-negative bacteria for locomotion. in order to function effectively, a flagellum must be firmly anchored to the cell wall. how will you be able to get across the idea that the peptidoglycan cell wall is strong enough to support such a mechanism? with a protein rod that passes through the cell wall and protein rings used to anchor it in the membranes, these basal bodies are the rudimentary biological motors that use atp power to spin the hook and the flagella attached to it. bacterial flagella have a biological motor that spins within the cell wall and is powered by atp. this allows the flagella to spin in a whiplike motion to propel the bacterium.