Which of the following statements about elements and compounds is accurate?
A. Elements are many different types of atoms together but
compounds are just one type of atom.
B. Elements are pure substances that cannot be broken down
physically but compounds are pure substances that can be broken
down physically.
C. Elements are not found on the Periodic Table but compounds are
found on the Periodic Table.
D. Elements are pure substances that cannot be broken down
chemically but compounds are pure substances that can be broken
down chemically.

If a checkpoint detects damaged dna, the checkpoint may

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.

Drag the tiles to the correct boxes to complete the pairs. not all tiles will be used. match each type of organism to a characteristic that describes it.