The PCR technique doubles the amount of DNA in a sample in each cycle. If you started the PCR technique with two fragments of double-stranded DNA, calculate how many double-stranded DNA fragments you would you have after four cycles.

In natural selection, what is actually “selected? ” a) alleles are directly selected b) genotypes are directly selected c) phenotypes are directly selected d) entire populations are directly selected

Which of the following is not a defining characteristic of plants?

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.