Fertilization of the haploid sperm and egg in animal species result in the restoration of the number of chromosomes in the zygote.

meteorologists would compare a new weather map with one 24 h old to see how fast a front is moving.

enzyme active site and substrate specificity

enzymes bind with chemical reactants called substrates. there may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. in some reactions, a single-reactant substrate is broken down into multiple products