A female guinea pig that was pure-breeding for white fur, mated with a male guinea pig that was pure-breeding for brown fur.
All the offspring had brown fur.
One of the male offspring mated with a female with white fur.
What proportion of white offspring would be expected from this cross?
one half
none
one third
O one quarter

one half

Because they both were pure breed (bb and BB) and all the offspring came out as brown that means that brown is the dominant trait. So the offspring are all Bb and if the offspring mated with a white fur she would have to be bb meaning their children woild be either Bb or bb

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.