B. The Threshold describes the minimum level of stimulus required to ctive a neuron. Hope that helps
D. Eukaryotic cells It happens in both plant and animal cells
B) The enzyme has active sites where the substrate binds with the enzyme to form a complex. When the substrate binds to the active site, an induced fit is formed where the enzyme changes its shape in order to better serve the substrate and lower the activation energy of the reaction
The flooding of half part of the forest have successful separate the population of frogs in that ecosystem into two different set of frogs. This is an example of allopatric speciation, that is, the population become separated as a result of geographical barrier. This separation will make the two set of frog population to become new species. On the long run, the two species may become unable to relate sexually.
