The most common map used is ordnance survey maps
Because as trials go on scientists discover more information and alter the theories and that is why they are referred to as a "theory" instead of a scientific "law"
50% of their offsprings will have the recessive trait because if you use Punnett square to analyze the data you will see that only 50% of their children will have Tt as their allele
An organism can get new cells from either cell growth where the numbers of organelles increase or during mitosis.