Dr. Semmelweis, a physician from Austria, wanted to locate the cause of childbed fever in his maternity wards. He suggested that the doctors in the hospital were
transferring a disease-causing substance to the pregnant mothers because they were
not washing their hands. His suggestion was a:
observation
hypothesis
theory
controlled experiment

Hydrilla (hydrilla verticillata) is an invasive aquatic plant and one of the most serious aquatic pests in florida. hydrilla has already been introduced to hundreds of bodies of water throughout florida, hydrilla is difficult to control because it grows rapidly and survives in many different water depths and conditions. hydrilla • describe how hydrilla affects native plant and animal species. include both a biotic and an abiotic limiting factor. • suggest one biotic and one abiotic recommendation that could slow the spread of hydrilla

Guinea pig coat color is determined by a single gene. the allele for black coat color is dominant to brown. in a cross between twoblack-haired guinea pigs, 20 offspring are born. if both parents were heterozygous, probability would predict that approximately howmany of the 20 offspring would have brown hair?

All organisms contribute some water to the water cycle by conducting