Imagine you are in a laboratory. you are exploring the following reaction: a + b → c when the product c is created, bubbles form. when 10ml of a is added to 10ml of b, the reaction takes twenty seconds. your teacher gives you three unknown substances (x, y, and z), one of which is a catalyst for the reaction. design an experiment to test substances x, y, and z to determine which one is a catalyst for the reaction.

The health, management and conservation of biodiversity, is a challenge facing ecosystems worldwide. the major factors that affect the health and function of the great barrier reef are climate change and pollution. which question investigates the effects of a biotic factor on the reef ecosystem?

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

Astudent is looking through a microscope at some cells of an onion root tip. many of these cells are undergoing division since the root tip grows quickly and requires more cells. which cell most recently underwent metaphase? w x y z