Order the following events in quorum sensing by Staphylococcus aureus: 1. Exotoxin expression increases, while expression of surface adhesins decreases. 2. AgrB-D-C-A operon is expressed at low levels. 3. RNA III accumulates. 4. AgrD peptide is processed and secreted by AgrB, creating the mature pheromone. 5. Pheromone accumulates when population densities are high. 6. AgrC phosphorylates AgrA. 7. AgrA-P binds to promoters P2 and P3, activating both. 8. Pheromone binds to the sensory kinase AgrC. Group of answer choices

Apopulation of black bears depends on salmon from a stream for food. if a drought causes the stream to run dry one year, how will this likely impact the black bear population?

Select the word from the list that best fits the definition a system made of 25 satellites

The kidney filters potentially toxic substances in the blood, and thus “clears” the blood of those substances. this clearance function is dependent upon and proportional to the diffusion gradient of the substance across filtering capillaries, i.e. if the concentration of the substance is doubled, twice as much will be cleared from each ml of blood that is filtered. suppose that the body produces a constant amount of a substance x per unit of time. the kidneys eliminate substance x at a rate directly proportional to the concentration of the substance and the volume of blood cleared each minute (c): elimination = c × [x], where [x] is the steady-state concentration of substance x. imagine an individual with an initial concentration of x equal to [x]0 who develops kidney disease. her baseline clearance c0 drops to one half of the original (½c0). what is the new steady state concentration of x? (for simplicity, assume that substance x is 100% filtered by the kidney).