What is used to represent something too big or too small to be observed directly

An equation or physical object that represents something that is too big, too small, too fast, or too slow to observe directly. Constant.

the answer is c.) there is a warm front in region a and a stationary front in region b.

an organism's phenotype is the  form of a trait  that it  displays. for  flowercolor, a pea  plant  can  display  a phenotype of purple or white flowers. an organism's  genotype  is the alleles of a gene it contains. based on his data, mendel concluded that a phenotype can be  determined  by more than one  genotype.