What is the difference between a hypothesis and a theory? A. A hypothesis is a possible explanation of a single event based on
observation, while a theory is a unifying explanation based on
many experiments and observations.
B. A theory is a possible explanation of a natural event that has not
been tested. A hypothesis is a question that cannot be answered
through scientific methods.
C. A hypothesis has been tested, but a theory cannot be tested.
D. A hypothesis is a description of events, but a theory explains why
the events took place.

An adult who follows a 2000-kcal healthy u.s.-style eating pattern should consume ounce-equivalents from the protein foods group per day.

Read this summary of a scientific theory: "cells are the most basic structural and functional units of life. all living organisms are made up of one or more cells. all cells that are alive in the world today came from pre-existing cells." which of the following would require this theory to be modified? -a.) a survey finds that a majority of people believe viruses carry out the basic processes of life. -b.) a prominent scientist says she feels strongly that one day the theory will be challenged by life on other planets. -c.) the dna of unicellular and multi-cellular organisms is shown to have many fundamental similarities. -d.) scientific observations show that microscopic organisms living in the deep ocean are not made up of cells.

Polar zones are cold and tend to be dry because of a pressure system of cold. low high