Please help me with this biology thing.

1.

a)dd

b) dd

c) 0%

2.

a) 25%

b) 75%

c) 25%

3.

a) 03

b) 0

c) tt

4.

a) FF x ff OR FF x Ff OR FF x FF

b) Because all the children have freckles

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).

b tumor cells have a cell wall instead of a membrane

explanation:

tumor cells different from normal cells because tumor cells have a cell wall instead of a membrane.