Two interactions within an ecosystem are predation and parasitism. In predation, predator organisms feed on prey organisms. In parasitism, parasites depend on host organisms. Which of the following correctly describes the relative numbers of organisms in parasitism or predation?

Which blood cell spend most of their time in the lymphatic system?

Which of these is not a nucleotide base found in dna?

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.