The activity of an Enzyme is affected by its environmental
conditions. Changing these alter the rate of reaction caused
by the enzyme. In nature organisms adjust the conditions of their
enzymes to produce an Optimum rate of reaction where necessary
or they may have enzymes which are adapted to function well in
extreme conditions where they live.
Restriction enzymes are DNA cutting enzymes found within bacteria. They can cut the DNA molecule.
Punnet squares are a useful tool for predicting what the offspring will look like when mating plants or animals. Reginald Crundall Punnett, a mathematician, came up with these in 1905, long after Mendel's experiments. Let's take a look at how Punnet squares work using the yellow and green peas example from im not sure about the tree by three thing but maybe this will help :)
The empirical formula is the simplest whole number ration that defines constituent atoms in a species. The molecular formula is always a multiple of the empirical formula.
Molecule Formula = 78.0 • g • mol ^ -1 = n(12.011 + 1.00794) • g • mol ^ -1
78
N = ——————————- = 6
12.011 + 1.00794
Molecular Formula = C6H6