When loading samples into an agarose gel
a. add 6x dye to ALL samples and pipet the SAME total volume for each well.
b. use the SAME micropipetter tip for ALL samples.
c. add control DNA to ALL your samples.
d. load ALL samples BEFORE electrophoresis buffer is added fully over the gel in the electrophoresis rig.
e. always go to the second stop of the micropipette to fully dispense ALL of the sample into its well.

a "theory" a suggestion that is not 100 % accurate, or a figure. some people say its a theory because they of all the passed theory's about one subject. it depends sometimes theory might be accurate and sometimes they are.

1. loamy sand is about 80% sand with 10% clay and defined mostly by sand particles with some clay to provide structure and fertility. the sand particles are easily visible and the soil holds structure but breaks apart easily.

2. scott sand can improve his soil quality by incorporating more silt and organic matter into the soil. peat moss and organic matter can also be incorporated.

i believe it's c. the trait for large beaks will be passed on to future generations through natural selection.

since eventually smaller beaks would have to find another source of food or even eventually just die out from the lack of food.