Context and question: Epigenetic changes in eukaryotic biology serve to regulate the process of cellular differentiation. During morphogenesis, totipotent stem cells become the various pluripotent cell lines of the embryo, which in turn become fully differentiated cells. A single fertilized egg cell, the zygote, gives rise to the many different plant cell types including parenchyma, xylem vessel elements, phloem sieve tubes, guard cells of the epidermis, etc. as it continues to divide. The process results from the epigenetic activation of some genes and inhibition of others.
What process causes changes in plant cells?
Answer: Epigenetic changes
Context and question: On 1 September, Germany invaded Poland from the west. Within the first few days of the invasion, Germany began conducting massacres of Polish and Jewish civilians and POWs. These executions took place in over 30 towns and villages in the first month of German occupation. The Luftwaffe also took part by strafing fleeing civilian refugees on roads and carrying out a bombing campaign. The Soviet Union assisted German air forces by allowing them to use signals broadcast by the Soviet radio station at Minsk allegedly "for urgent aeronautical experiments".
How didn't the Russians communicate to the Germans in regards to bombing civilians trying to flee cities?
Answer: unanswerable
Context and question: Time has long been a major subject of study in religion, philosophy, and science, but defining it in a manner applicable to all fields without circularity has consistently eluded scholars. Nevertheless, diverse fields such as business, industry, sports, the sciences, and the performing arts all incorporate some notion of time into their respective measuring systems. Some simple definitions of time include "time is what clocks measure", which is a problematically vague and self-referential definition that utilizes the device used to measure the subject as the definition of the subject, and "time is what keeps everything from happening at once", which is without substantive meaning in the absence of the definition of simultaneity in the context of the limitations of human sensation, observation of events, and the perception of such events.
What does time measure?
Answer:
unanswerable