Restriction enzymes and or restriction endonucleases are involved at recognizing specific sequence of nucleotides and cutting or splicing them at appropriate regions to produce fragments that can either be sticky ends or blunt ends depending on where they cut and the nature of nucleotides involved within the fragments. They play an important role in genetic engineering, as geneticists can use them for placing into extra chromosomal information and or content of plasmids in certain bacteria, from other sources, for instance antibiotics, grow and or produce many individual colonies of bacteria, isolate them and one would have many sequences for instance that can code for an antibiotic that can be extracted and used further. Assuming the bacteria's plasmid can take in that sequence.
Answer:
In the mentioned case, both the cells will start to perform replication of their DNA. In the case of G0, that is, the stationary phase, the mammalian cell can pass the restriction point with the supplementation of extracellular proliferation signal. While in the case of G1, which actually does not require any kind of external proliferation signal, as once the cell is in G1 phase, it is ready to go get the next phase. However, both the mammalian cells will cease or halt at G2 checkpoint.
B. The Threshold describes the minimum level of stimulus required to ctive a neuron. Hope that helps
B. Controlling the flow of Blood to the skin seems to make the most sense
