What are levels of ecology and how can we remember them

Describe how a non-resistant staphylococcus aureus bacterium can produce a bacterium that is resistant to methicillin

Lactase is essential for digesting lactose in milk. this enzyme is specific for this sugar. why? molecules and active sites vary in size; only properly sized molecules can fit.there is a precise compatibility between the active site and the lactose molecule.specificity refers to the action of the enzyme, such as hydrolysis, and relatively few molecules can be hydrolyzed.reaction-specific enzymes assume a fit by folding around the most numerous substrate molecules.

Which layer of the eye completely surrounds the eye except for a dark, round opening called the pupil? a. sclerab. corneac. retinad. choroidthe answer is a sclera