16-22: Two protein kinases, K1 and K2, function sequentially in an intracellular signaling pathway. If either kinase contains a mutation that permanently inactivates its function, no response is seen in cells when an extracellular signal is received. A different mutation in K1 makes it permanently active, so that in cells containing that mutation a response is observed even in the absence of an extracellular signal. You characterize a double-mutant cell that contains K2 with the inactivating mutation and K1 with the activating mutation. You observe that the response is seen even in the absence of an extracellular signal. In the normal signaling pathway, does K1 activate K2 or does K2 activate K1

The earth consists of a variety of different organisms. despite their diversity, however, some similarities on the structural and metabolic levels may be seen. these similarities can be attributed to a. similarities among organisms in their proteins and nucleic acids. b. the ability of organisms to readily adapt to sudden environmental changes. c. similarities in organisms' habitats and niches. d. the ability of all organisms to interbreed and produce new species.

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.

The activity of the modern sample is 1.10 bq . how long does that measurement take?