Answer: 1) Bb = 100%; 2) BB = 25%, Bb = 50%, bb = 25%;
Explanation: The Punnett Square is a diagram in which shows the possible genotypes of a particular cross or breeding experiment.
1.) The crossing is between homozygous dominant and homozygous recessive or BB x bb. The Punnett Square is:
b b
B Bb Bb
B Bb Bb
So, as we can see from it, the crossing will give a progeny with heterozygous trait only or 100% Bb
2.) The crossing is between two heterozygous or Bb x Bb. The Punnett Square is:
B b
B BB Bb
b Bb bb
We can see this crossing gives a bigger variety of traits:
The progeny with genotype BB or homozygous dominant has 25% chance of happening.
For genotype Bb of heterozygous, it has a 50% chance of occuring.
For homozygous recessive or bb, it is a probability of 25%.