The photograph shows soil layers. What is the bottom layer of soil?

Over the past 60 years, many amphibian species have experienced significant population declines and some species have become extinct. scientists suspected that local human activities such as the destruction of wetlands, regional pollution, and deforestation were the main reasons for these losses. however, research over the past 20 years reveals significant amphibian population declines in protected areas of the world, such as nature preserves and parks. these global declines suggest widespread problems including increased ultraviolet radiation, acid rain, and disease. in switzerland, for example, 14 of the 20 native amphibian species are threatened with extinction. chytridiomycosis is a fungal disease first identified in 1998 as a cause of massive amphibian deaths. in some severely impacted populations, a few individuals have survived, perhaps because of some natural resistance. if these resistant individuals continue to survive and prosper, new resistant populations might emerge. this would be an example of the founder effect artificial selection genetic drift natural selection sexual selection

The process of meiosis produces only gametes, eggs or sperm. according to the diagram, how many sperm are formed from each cell that undergoes meiosis?

An enzymatic hydrolysis of fructose-1-p, fructose-1-p(aq) + h2o(l) - fructose (aq) + pi (aq) was allowed to proceed to equilibrium at 25°c. the original concentration of fructose-1-p was 0.2 m, but when the system had reached equilibrium, the concentration of fructose-1-p was only 6.52 x 10^-5 m. calculate the equilibrium constant for this reaction and the free energy of hydrolysis of fructose-1-p.