Entrance into piaget's preoperational stage of development is marked by

Proteins are made from amino acids. an amino acid has three parts that are joined to a central carbon atom. identify the three parts that create an amino acid.

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?

Which organelle breaks down sugar molecules that supply energy to the cell ?