Allen and andrew both have the same biological parents. why do they not resemble either of there parents

According to piaget, children have acquired the cognitive skill of conservation when they're able to a. understand that six ounces of liquid in a jar and six ounces in an elongated tube are equal. b. understand the viewpoint of other people. c. relate objects around them to their own needs. d. realize that the term heavy describes an object one way and the term big describes it another way. it is not b nor c. did this 2 x wrong..

Transmission electron microscope are best for viewing a) microorganisms in pond water b) internal organs of a mouse c)internal structures of a cell d) surface features of a specimen

Freckles are a dominant trait in humans. both of the girls have the genotype ff for freckles. if either one marries a man with no freckles, what are the chances that their children will have freckles?