What is a proposed explanation that can be tested

What type of specimens where you able to see under each of the microscopes in the microscope activity

Guinea pig coat color is determined by a single gene. the allele for black coat color is dominant to brown. in a cross between twoblack-haired guinea pigs, 20 offspring are born. if both parents were heterozygous, probability would predict that approximately howmany of the 20 offspring would have brown hair?

Witch theory suggests all living things are made up of cell or cells