What is meant by pure substances?

Answers to mastering biology drag the labels to their appropriate locations to complete the punnett squares for morgan's reciprocal cross. drag blue labels onto the blue targets to indicate the genotypes of the parents and offspring. drag pink labels onto the pink targets to indicate the genetic makeup of the gametes (sperm and egg). labels can be used once, more than once, or not at all. hints

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 of the following statements accurately defines epidermis? a. a thick protein fiber composed of the protein collagen b. hard, dense bone tissue found on the outer surface of a bone c. single layer of epithelial cells and the underlying basal lamina d. outer, protective layer of the skin composed of stratified squamous keratinized epithelial tissue