The development factored into the development of complex organisms.

ozone
oxygen
cyanobacteria
all of the above

the end of the paleozoic era was signaled

the development of humans
mass extinction of land and sea animals
the development of organisms with hard parts
both a and b

reptiles evolved from an ancestor of amphibians that developed a(

egg with a strong outer shell that kept it from drying out
hard set of teeth
thick eyelid
long tail

What sre the effects of hemolytic disease of a newborn

Directions: read the descriptions of the four islands presented in the lesson. 1. list two new traits that each new species of rat might demonstrate as it adapts to the conditions on each island. 2. introduce one of the four new rat species to another island and describe one challenge it would encounter and one success as it adapts to its new environment.

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.