Natural selection on
peppered moths vary in darkness. some have a lighter coloration and some have a darker coloration. before the industrial revolution only 2% of the moth population was darker coloration. after the industrial revolution, 95% of the population showed this darker coloration. birds eat the moths they can see on the trees.

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

the most common type of reef is the fringing reef. this type of reef grows seaward directly from the shore. they form borders along the shoreline and surrounding islands.

it is called the mitotic spindle