The rate r at which a disease spreads in a population of size p is jointly proportional to the number x of infected people and the number p − x who are not infected. an infection erupts in a small town with population p = 8000. (a) write an equation that expresses r as a function of x. (use k for the constant of proportionality and p for the population.) r=kx(p−x) (b) compare the rate of spread of this infection when 90 people are infected to the rate of spread when 900 people are infected. which rate is larger? by what factor? (round your answer to one decimal place.)

You decide that the introduction should also discuss the extremophiles that are referred to as the archaea. these single-cell organisms are considered "extremophiles" due to their ability to survive and reproduce in environmental conditions that would be hostile for most living organisms. archaea species have been isolated from highly acidic sulfur springs, ocean floor thermal vents with temperatures that exceed boiling, and subarctic ice well below freezing. while still considered to be prokaryotic, the archaea have numerous differences that place them apart from the bacteria. choose the characteristics that separate the archaea from other prokaryotic cells. select all that apply. view available hint(s) select all that apply. archaea lack true peptidoglycan in their cell walls. the morphology of the cell is rigid and is geometric in shape, similar to a sphere or cylinder. the cytoplasmic membrane lipids of archaea have branched or ringform hydrocarbon chains. all currently identified and characterized archaea have been linked as the causative agent to an animal or human disease.

In which layer do organisms on earth love?

Use the phylogenetic tree to the right to determine which statement below is true. organisms a and f are not related. organism e is more closely related to organism b than organism f. organisms c and d are more closely related than organisms a and b. phylogenetic trees